SENSORS

Better sensors and, crucially, better ways of handling the data that they produce, are needed by the US military to properly exploit the advanced technologies being developed for intelligence, surveillance and reconnaissance (ISR) applications

US warfighters and analysts were now faced with a monumental and escalating task to handle all of the information being provided. “We are swimming in sensors; drowning in data,” said the DARPA chief. Much of that data is produced by optical sensors, for example visible-range surveillance, infrared cameras and hyperspectral imager

“A TCP/IP for ISR”

And, referring to one of DARPA’s greatest past achievements; Dugan told delegates that the sensory overload could be aided by the development of a smart network, analogous to the Internet. “We need a TCP/IP for ISR,” she said, recalling the Internet Protocol research that DARPA embarked on in the early 1970s, and which generated the standards on which today’s Internet is constructed.

Doing that would ultimately enable the ISR equivalent of social networking, based on resilient and adaptable information architectures, said Dugan, referring to the natural hierarchies that result from the dissemination of true information across networking sites such as Facebook and Twitter, and which played a critical role in the revolutions that have swept Tunisia and Egypt.

DARPA projects that might evolve to offer that capability include the “Insight” effort that envisages a “global ISR workstation”. It aims to combine self-aware sensors, for

example hyperspectral images and Doppler lidar, to deliver more useful data to the military, in a form that can be directly exploited.

DARPA's MSEE to develop new mathematical language, race of sentient

machinesBy Christopher Trout   posted Jan 13th 2011 6:25AMThe hyper-ambitious folks at DARPA are totally over the current state of military data collection, and they're pretty sure they know how to fix it: teach sensors how to think. Well, they've got an idea how to fix it, but they've put out a call for mathematician to do the dirty work. The Mathematics of Sensing, Exploitation, and Execution (MSEE) program seeks a unified mathematical language that can teach sensors not only to collect data, but to interpret, and act on it too. The aim is to eliminate the "data deluge" that comes from ever-increasing streams of information, like cellphone intercepts and video drone feeds, allowing analysts to focus on the important stuff. Currently the onus falls on humans to interpret the overwhelming amount of information collected by military sensors, but DARPA is confident that the right algorithm could have machines interpreting the world as early as 2014. Which gives you right around three years to fulfill every fantasy you've ever had.

Wide area infra-red persistent surveillance system.

Last week DARPA awarded two contracts funding high-resolution, wide area infra-red persistent surveillance system. The U.S. Air Force awarded BAE Systems about US$50 million to deliver a high resolution sensor for persistent surveillance over a wide area. BAE has been developing such a system under two other programs – DARPA  Autonomous Real-time Ground Ubiquitous Surveillance-Imaging System (ARGUS-IS) and  Army Airborne Wide Area Persistent Surveillance Sensor (AWAPSS)programs. The current system will be designed to enable a joint forces command in theater to constantly monitor critical areas of interest, using infra-red and video imagers, offering high degree of target location accuracy.

Part of the capabilities of WAMI sensors are to automatically track moving targets over a wide area. These images present two methods of presenting moving targets over surveillance images, showing multiple individual tracks and functional areas determined based on densities of movements.

DARPA is also seeking to improve the processing of the vast volumes of imagery data produced by WAMI sensor systems. Last week the agency has awarded Kitware Inc. a US$13.8 million contract for the development of image analysis support for wide area motion imagery systems. Kitware is developing these new workstations as part of the Persistent Motion Imagery Analysis Tool for Exploitation (PerMIATE) program, assisting analysts in discovering and analyzing high-value intelligence content embedded in massive amount of WAMI data, both online and forensically. Leveraging advanced computer vision, machine learning, artificial intelligence, and data visualization in an integrated workstation PerMIATE will reveal and highlight the most critical information in a clear and intuitive presentation, enabling video analyst to quickly validate or refute intelligence leads through deep exploration of the underlying evidence, resulting in substantial reductions in analyst workload as well as increasing the quality and accuracy of intelligence yield. DARPA is developing such analytic tools as part of the Persistent Stare Exploitation and Analysis System (PerSEAS) currently underway.

The New Generation of Persistent Wide Area Motion Video Surveillance (WAMI) Systems

The Defense Advanced Research Projects Agency (DARPA) is moving forward with groundbreaking programs providing the warfighter persistent, wide area coverage of large areas, enabling joint forces at tactical and operational levels conducting ubiquitous, monitor of urban or rural areas, attempting to alert, intercept and eliminate hostile elements in a secured area, requiring minimal presence on the ground. DARPA and the U.S. Ari Force have been supporting several programs developing platforms, sensors, image processing and analyst support systems, which will bring such capabilities to reality.

Since 2007 the U.S military has fielded the first generation of airborne wide area surveillance – namely the Army's Constant Hawk and Air Force and Marine Corps Angel Fire. Analysts operating these systems try to determine all the entities going to and from an event or point of interest to ascertain the unique source of destination of the people or vehicles associated with a specific event. These manual tracks take many hours and are prone to human error. Furthermore, they result in text reports or simple sketches which cannot be processed by machines. Therefore, existing WAMI assets like Angel Fire are limited to a small number of subframes and used primarily for force protection. Events of interest can include staring points and destinations of tracks and nodes of related entities within the persistent field of view. They can also include activity and event-based normalcy and anomaly detections, such as unique driving behaviors occurring before the detonation of suicidal vehicle. Other types of events can be used to discover or highlight 'patterns of life' associated with a variety of network types, including social, political, regional, economic or military networks.

Part of the capabilities of WAMI sensors are to automatically track moving targets over a wide area. These images present two methods of presenting moving targets over surveillance images, showing multiple individual tracks and functional areas determined based on densities of movements. Photos: Kitware Inc.

WAMI surveillance efforts are directed primarily around roads, buildings and distinctive scene features. Exploitation of these entities yields tracks but, in a complex urban environment these tracks are severely fragmented due to occlusions, stops and other factors

involving irregularities. PerSEAS will use advanced algorithms to associate these track fragments to identify localized events and discover relationships and anomalies that could be indicative of suspicious behavior, match previously learned threat activity, or match specific, user defined patterns. While a localized event may occur over a small 'window' of time and space, the overall activity sequence may span over much longer time and wider area – PerSEAS will be able to track, link and highlight as potential threat activity, by pooling together multiple weak pieces of evidence, the system's engine should be able to detect a potentially threatening activities.

Persistent Stare Exploitation and Analysis System (PerSEAS) is a software system developed to automatically and interactively discover actionable intelligence from wide area motion imagery (WAMI) of complex urban, suburban and rural environments. Used in a forensic mode, the system will exploit hours and days of WAMI data to identify threat activities and the underlying threat indicators. Used in a near real-time mode, the system will alert the user to developing threat activities intime to interdict. In addition to the electro-optical/infrared (EO/IR) data available from WAMI sensors, PerSEAS will interact with other intelligence sources. Overall, the system will significantly reduce the time required to perform current exploitation tasks and greatly enhance the analysts' ability to exploit the huge volume of imagery data available to them.

DARPA awarded Kitware Inc. a US$13.8 million contract for the development of image analysis support for wide area motion imagery (WAMI) systems. Kitware is developing these new workstations as part of the Persistent Motion Imagery Analysis Tool for Exploitation (PerMIATE) program, assisting analysts in discovering and analyzing high-value intelligence content embedded in massive amount of WAMI data, both online and forensically. Leveraging advanced computer vision, machine learning, artificial intelligence, and data visualization in an integrated workstation PerMIATE will reveal and highlight the most critical information in a clear and intuitive presentation, enabling video analyst to quickly validate or refute intelligence leads through deep exploration of the underlying evidence, resulting in substantial reductions in analyst workload as well as increasing the quality and accuracy of intelligence yield.

Persistent surveillance capabilities like those available by PerMIATE require platforms with extremely long endurance. The U.S. military is considering several alternatives for these tasks, including the A160 Hummingbird rotary-wing UAV, a tethered aerostat platform or an airship.

ITT Introduces New Sensor Architecture Supporting Wide Area Airborne Surveillance (WAAS) Capabilities

ITT has developed a Wide Area Airborne Surveillance (WAAS) sensor architecture enabling the warfighter to access collection of data from multiple sources. The company is also presenting a new day/night WAAS W turret sensor designed to operate with the new architecture. The new sensor generates multiple, simultaneous high resolution views of specific region across the payload's widest footprint, enabling users to track multiple targets in different parts of the field of view. The system enables the user to instantly obtain high resolution, detailed images sufficient to track dismounts.

The primary sensor is a 160 megapixel imaging sensor coupled with a fixed optical lens supporting wide field of view coverage in day and night). This sensor captures high resolution images at a rate of two frames per second. A mid-wave infrared 64 Megapixel sensor also scans a fixed field of view at a rate of 'multi frames per second', according to ITT. Weighing 144 kg (317 lbs) including all peripherals, the new payload is gyro stabilized in five axes, maintaining an accuracy of 2 micro-radians RMS. With outer diameter is 63 cm (24.8") the WAAS W is sized and designed to be compatible with manned aircraft and large unmanned platforms.

The new architecture supports instant playback and forensic review of data, 'progressive image streaming' facilitating rapid delivery of motion video and high resolution images, eliminating lengthy waiting for image download on low bandwidth uses. The system supports low bandwidths under 10 Mb/sec and up to full Common Datalink (CDL) speed of over 200 Mb/sec

Northrop Grumman joins Honeywell in DARPA program to develop precision micro-gyro sensor for smart munitions

RLINGTON, Va., 30 March 2011. Micro-sensor experts at the Northrop Grumman Corp. Electronic Systems segment in Woodland Hills, Calif., are joining a project of the U.S. Defense Advanced Research Projects Agency (DARPA) in Arlington, Va., to develop a miniature gyroscope for smart munitions, ships, vehicles, aircraft, and infantry soldiers.

DARPA scientists awarded Northrop Grumman a $4.8 million contract Monday for the three-year Microscale Rate Integrating Gyroscope (MRIG)program, which seeks to develop a micro-sensor vibrating-structure gyroscope to measure rotation over a wide range of dynamic conditions.

Northrop Grumman joins the Honeywell Aerospace Microelectronics & Precision Sensors segment in Plymouth, Minn., on the MRIG micro-gyro project. DARPA awarded Honeywell a $5.9 million MRIG research contract earlier this month.

DARPA is asking microelectronics experts at Northrop Grumman and Honeywell to develop the micro-scale gyro for self-contained chip-scale inertial navigation and precision guidance systems that would help eliminate dependence on the satellite-based Global Positioning System (GPS) or any other external signals for uncompromised navigation and guidance.

A vibrating-structure gyroscope operates on the principle that a vibrating object tends to keep vibrating in the same plane as its support is rotated. It is simpler and cheaper to design and build than is a conventional rotating gyroscope of similar accuracy, DARPA officials say.

DARPA scientists are asking the two companies to develop these kinds of micro sensors as crucial parts of advanced inertial measurement units, and small enough for guided munitions, hand-held devices, and add-in portable guidance, navigation, and control units.

Northrop Grumman and Honeywell experts will develop micro-gyros that are not influenced by the kinds of mechanical shocks, temperatures, vibrations, spin rates and accelerations that are common in guided munitions. The devices that Northrop Grumman and Honeywell scientists will develop are expected to operate on no more power than a few tens of milliwatts.

DARPA's primary goal of the MRIG program is to create a vibratory gyroscope able to measure the angle of rotation directly such that the gyros will extend their dynamic range, as well as eliminate the need for integrating angular rate information. In this way, DARPA and Honeywell researchers expect to eliminate an accumulation of errors due to numerical and electronic integration.

DARPA scientists are asking Northrop Grumman and Honeywell to develop isotropic two-degree-of-freedom resonators -- especially microscopic 3-D shell resonators -- which are spheres, wine-glass shaped structures, or any spatially distributed shells with an axis of symmetry.

Rate integrating gyroscopes have high dynamic range, accuracy due to direct measurement of the angle of rotation, and ability to operate interchangeably in the whole angle and angular rate modes, DARPA experts point out.

The two companies have substantial challenges ahead, as rate integrating gyroscope technology has never been demonstrated on the microscale level. Rate integrating gyroscope miniaturization would offer the potential for developing an inertial navigation system for spin-stabilized missiles, pointing technology for high-G munitions, and azimuth-based target mapping.

For more information contact Northrop Grumman Electronic Systems online at www.es.northropgrumman.com, or Honeywell Aerospace Microelectronics & Precision Sensors (formerly the Honeywell Solid-State Electronics Center) online at www.ssec.honeywell.com, or DARPA at www.darpa.mil.

DARPA to develop microscale navigational gyro for guided munitions and hand-held devices

Apr 29, 2010

Posted by John Keller

ARLINGTON, Va., 29 April 2010. Navigation and guidance experts at the U.S. Defense Advanced Research Projects Agency (DARPA) in Arlington, Va., are asking industry to develop a miniature gyroscope for precision-guided munitions, ships, vehicles, aircraft, and even individual combatants.

DARPA on Wednesday issued a broad agency announcement (DARPA-BAA-10-39) for the three-year Microscale Rate Integrating Gyroscope (MRIG) program, which seeks to develop a microscale vibrating-structure gyroscope to measure rotation over a wide range of dynamic conditions.

Essentially, DARPA wants to develop a component for self-contained chip-scale inertial navigation and precision guidance systems that would help eliminate the dependence on the satellite-based Global Positioning System (GPS) or any other external signals for uncompromised navigation and guidance.

A vibrating-structure gyroscope operates on the principle that a vibrating object tends to keep vibrating in the same plane as its support is rotated. It is simpler and cheaper than is a conventional rotating gyroscope of similar accuracy.

DARPA scientists envision these micro sensors to be crucial parts of advanced inertial measurement units, and small enough for guided munitions, hand-held devices, and add-in portable guidance, navigation, and control units.

The kinds of mechanical shocks, temperatures, vibrations, spin rates and accelerations of guided munitions must not influence the micro gyro's performance, and the device must operate on no more power than a few tens of milliwatts.

In addition, DARPA expects these micro gyros to be fabricated with large-scale manufacturability, not on boutique processes that require individual fabrication of components and subsequent discrete assemblies.

DARPA's primary goal of the MRIG program is to create a vibratory gyroscope able to measure the angle of rotation directly to extend the dynamic range and eliminating the need for integrating the angular rate information. In this way, DARPA researchers expect to eliminate an accumulation of errors due to numerical and electronic integration.

DARPA is looking for industry proposals that involve isotropic two-degree-of-freedom resonators -- especially microscopic 3-D shell resonators -- which are spheres, wine-glass shaped structures, or any spatially distributed shells with an axis of symmetry.

Rate integrating gyroscopes have high dynamic range, accuracy due to direct measurement of the angle of rotation, and ability to operate interchangeably in the whole angle and angular rate modes, DARPA experts point out.

Still, rate integrating gyroscope technology has never been demonstrated on the microscale. Rate integrating gyroscope miniaturization, however, offers the potential for developing an inertial navigation system for spin-stabilized missiles, pointing technology for high-g munitions, and azimuth-based target mapping.

Companies interested should send proposal abstracts to DARPA no later than 2 June 2010, and full proposals no later than 20 July 2010.

For questions or concerns, contact the MRIG program manager, Andrei Shkel, by phone at 703-351-8468, by e-mail atDARPA-BAA-10-39@darpa.mil, by fax at 703-812-5051, or by post at DARPA/MTO, ATTN: DARPA-BAA-10-39, 3701 North Fairfax Dr., Arlington, VA 22203-1714.

More information is online at https://www.fbo.gov/spg/ODA/DARPA/CMO/DARPA-BAA-10-39/listing.html.

Breakthroughs in inertial sensors to augment GPS will guide future of precision-guided munitions

Putting a smart bomb through a window during the first Persian Gulf War was just the beginning of the future ofprecision-guided munitions. Next up for smart munitions will be smart bullets for infantry weapons, GPS receivers built into the soldier's boot, eliminating enemy snipers before they have a chance to shoot, and counter-RPG systems.

Most of the world first became aware of the new era of precision guided munitions (PGMs) in the early days of the first Gulf war, when CNN correspondents, watching from the upper floors of their downtown Baghdad hotel, reported seeing an American missile fly down the street -- and turn a corner (see related story, Directed-energy weapons will be the next generation of precision-guided munitions).

The level of precision in smart munitions available in 1991, while revolutionary, is several generations obsolete less than two decades later. But what is now being developed in military and industrial labs will make today's precision-guided munitions seem even more crude by comparison, in less than a decade. Perhaps much sooner.

In a progression from hitting a specific building to hitting a specific room, the next generation will, among other things, turn the foot soldier into a precision strike weapon, able to navigate without GPS thanks to a chip in his boot, and to fire guided bullets at targets like would-be snipers before they have a chance to fire at him.

"GPS guidance is great -- so long as you precisely know where the target is"Dave Dorman, vice president business development & strategyAlliant Techsystems Advanced Weapons Division

Most precision-guided munitions today depend heavily on GPS for location and navigation, adding some advanced sensors for terminal target identification and guidance. Advances in inertial navigation systems (INS) also have added to the precision of weapons now deployed to Iraq and Afghanistan.

The future will be more focused on revolution than evolution involving new technologies to enhance the precision of precision strike weapons. Most of these efforts are still in the research and development -- especially the Defense Advanced Research Projects Agency (DARPA) -- with a significant number expected to leave the lab for fielding in the next decade.

A wide range of precision strike-related programs are scattered among several DARPA offices, such as Defense Sciences (DSO), Strategic Technology (STO), Microsystems Technology (MTO), Information Processing Techniques (IPTO). Some may share components or break-through technologies or ultimately may be combined to achieve a specific goal.

Precision Inertial Navigation Systems (PINS)

PINS is an effort to address the vulnerabilities of GPS navigation -- jamming, spoofing, blind spots, etc. -- by using ultra-cold atom interferometers to reduce the positional accuracy drift of INS by several magnitudes to achieve near-GPS accuracies. Such a system could be used as a backup in case of GPS denial, or as an alternative to GPS on some platforms.

"I feel like atom interferometry is the core technology for future improvements in high-end INS. We have been looking very hard at global strike and this is a technology that is very promising in that realm," says U.S. Air Force Lt. Col. Jay Lowell, PINS program manager within DSO. "If you set an INS down on a table, it thinks it is moving at one mile per hour, because that is the typical INS drift in an aircraft-size box. The smaller the box, the greater the drift. We're looking for a 70x improvement in that drift -- from a mile an hour to tens of meters an hour."

Basically, an atom interferometer takes a cloud of about 1 billion Cesium or Rubidium alkali atoms and cools them to a temperature one-millionth of a degree above absolute zero. Lasers then launch those atoms into an ultra-high vacuum enclosure, where their path is measured.

"We use one laser beam to split the cloud of atoms, making them behave like they are in two places at the same point in time. We then

use another laser pulse to recombine those atoms and, in that process, are able to determine the interference between the two paths that cloud took," he says. "What happens during that time when the two atom waves are separated tells us about the inertial forces that have acted on those atoms. And that inertial force is what we are after in a navigation system.

"Our current challenge is to improve the sensor bandwidth to enable operations with a 10G input, so it is not only useful underwater, but will be a navigation technology available for aircraft and missile applications, as well. The predominant challenge is improving the sensor bandwidth, miniaturizing and integrating subsystems to enable that."

The program is moving toward a targeted airborne test in about three and one-half years, he adds, while having a "routinely fieldable application around 2015 or 2016 is not out of the question".

EXtreme ACcuracy Tasked Ordinance (EXACTO)

EXACTO uses a combination of a maneuverable bullet and a real-time guidance system to track the target and deliver the projectile to target. Technology development includes the design and integration of aero-actuation controls, power sources and sensors, according to DARPA. The components must fit into the limited volume of a 50-caliber projectile and be designed to withstand a high acceleration environment. The EXACTO technology is planned for transition to the Army by 2012.

Based on a new .50 caliber BMG gun and improved scope, EXACTO would incorporate a variety of technologies, including fin- and spin-stabilized projectiles, internal or external aero-actuation control methods, projectile guidance technologies, tamper proofing, small stable power supplies, as well as advanced sighting, optical resolution, and clarity.

"DARPA's goal is to remove the effect on accuracy of target motion and random variances in the environment through use of a guided bullet," explains DARPA program manager Dr. Lyn Beamer (IPTO). "Such variances cannot be accounted for in the initial aim point and include unknown winds, range-to-target, altitude differences between shooter and target and round-to-round differences, among other factors."

One benefit of this is that EXACTO no longer requires snipers to take several calibration shots to 'walk' to the target for long-range shots or shots in adverse conditions, which avoids warning the target and risking their position. EXACTO is mid-way through phase I, which will demonstrate all key components, concluding with a simulation tying actual hardware together in a software environment to evaluate system performance. Phase II will demonstrate a working prototype.

Counter-Sniper Program (C-Sniper)

C-Sniper could be seen as the counter-weight to EXACTO, intended to detect and neutralize enemy snipers before they can engage U.S. forces. A primary objective is to deliver a field testable prototype as an integrated part of another DARPA program -- Crosshairs (see below). Able to operate day and night from a moving vehicle, C-Sniper will provide data and controls to point and track an on-board weapon the human operator then can use to engage the target before the enemy can fire.

According to DARPA, challenges to designing a combat-capable system include detecting enemy snipers carrying weapons before they fire a shot by determining where the shot may come from; developing techniques to reject clutter; reducing system design complexity by keeping the number of moving parts to a minimum; and integrating C-Sniper with Crosshairs on military vehicles.

Crosshairs

The purpose of the Crosshairs system is to detect enemy bullets, rocket-propelled grenades (RPGs) and mortars fired at U.S. military vehicles, and then prevent them from striking the vehicle.

"Crosshairs is really a set of five capabilities, and it's modular, so every vehicle may not have the full set," says DARPA program manager Dr. Karen Wood (STO). "Crosshairs capability includes being able to answer the question, 'What's coming in at me? What's the threat? And where is the shooter?' The next capability is, 'How do I respond?' The third is controls and display -- now I have a piece that tells me where in the scene the shooter or shooters are, so I can designate targets or improve my situational awareness.

"The fourth capability is networking. We use EPLARS (Enhanced Position Location and Reporting System) compatible radios, which are military standard, to network to the vehicles around me so they know there's a shooter over here shooting this particular threat. The fifth capability is an active protection system. In Crosshairs, we're using another DARPA technology called Iron Curtain, which defeats an incoming RPG round; we're looking at some of the more advanced rounds right now, as well."

Micro inertial navigation technology (MINT)

MINT seeks to create high-precision navigation aiding sensors that directly measure intermediate inertial variables, such as velocity and distance, to mitigate the error growth encountered by integrating signals from accelerometers and gyroscopes alone. The goal is to combine microscale inertial sensors and velocity sensors into an integrated circuit with very low power requirements, using energy harvesting technologies to replace batteries.

MINT would enable a variety of new applications, such as incorporating the sensor suite into the sole of a shoe for accurate and precise velocity sensing using zero velocity updaTing (ZUPTing) events while walking. In a GPS-denied environment, such as urban canyons or thick jungle canopy, that could provide navigation accuracies equal to or exceeding GPS, even after several hours of walking.

Phase I has demonstrated an average position error of four meters at the end of a half-hour walk, which is several orders of magnitude better than the direct, uncompensated integration of inertial information. Position and orientation are expected to be projected on a digital map and perhaps shared with a squad.

"We also are exploring some new initiatives when self-calibration algorithms will be applied to sensors themselves, thus limiting the growth of error, and a new self-calibration paradigm and ZUPTing-on-a-chip, which is based on Earth magnetic field updates," says program manager Dr. Andrei Shkel (MTO). "Those potentially new developments will be directly applicable to terminal guidance and other non-ground navigation/guidance."

A second DARPA goal is to combine inertial measurement units (IMUs) and velocity sensors for unmanned aerial vehicle (UAV) flight controls, enhancing the ability of several UAVs to navigate in close proximity while avoiding collisions.

"You can think of a UAV as the first step in precision strike, with precision guided munitions being an extension of that"David G. Dawes, manager of business development for DOD applicationsGoodrich ISR Systems

"The focus is to develop a precision zero velocity event detection sensor and incorporate it with a chip-scale MEMS IMU. The information is processed by the Zero Velocity Update Algorithm, resetting the Kalman Filter estimator when a zero velocity event is detected (i.e., foot touching the ground)," Shkel says. "Effectively,

the performers are exploring several concepts for a personal micronavigation device that uses a high-resolution, gait-corrected IMU."

NGIMG involves the development of tiny, low-power, rotation rate sensors that can provide navigational accuracy in GPS-denied environments for individual soldiers, micro-UAVs, unmanned underwater vehicles and even insect-sized robots. Together with CSACs (see below) and location-tracking algorithms that harness additional kinetic information, chip-scale NGIMG's should allow man-portable dead-reckoning devices with unprecedented precision, with and without GPS.

DARPA believes the subsequent growth in applications also is expected to generate a need for high volume manufacturing that, combined with wafer-level batch fabrication methods enabled by MEMS technology, should substantially lower the cost of miniature navigation systems and further fuel expansion NGIMG applications.

According to Shkel, who also is program manager for NGIMG and CSAC, among the enabling technologies required for NGIMG are chip-scale atomic precession, spin-stabilization of Rubidium and Cesium isotopes, duality of elastic waves and electrostatic levitation and high-speed spinning of micro-structures.

Chip-scale atomic clock program (CSAC)

The CSAC program is designed to create ultra-miniaturized, low-power atomic time and frequency reference units that will achieve, relative to present approaches, a 200X reduction in size and a 300X reduction in power consumption, with no loss in accuracy. A projected application is a wristwatch-size high security UHF communicator and jam-resistant GPS receiver, but overall CSAC could drastically improve channel selectivity and density for all military communications.

It also will enable ultra-fast frequency hopping in synchronized spread-spectrum communication for improved security and jam resistance and strong encryption in data communication. In military GPS receivers, it will greatly improve the jamming margin in high-jamming environments, reacquisition capability and position identification accuracy. In surveillance applications, CSACs can be used to improve resolution in Doppler radars and enhance accuracy of location identification of radio emitters. Other uses include missile and munitions guidance, robust electronic and information defense networks and high-confidence identification-friend-or-foe.

Shkel says stable atomic transitions between energy levels and laser cooling of atoms on a micro-scale are among the required enabling technologies for CSAC, which already has been selected by the Army for its Manufacturing Technology efforts and will be tested for performance in a weightless environment aboard the International Space Station in 2010.

In combination, CSAC and NGIMG offer "a self-contained position, orientation and timing solution on a single chip," he adds. "It will not require any external signals and cannot be affected by weather, interference or deception by enemies."

Beyond DARPA

Army, Air Force and Navy labs and dozens of contractors, working both government-funded and internal development programs, also are pushing the state-of-the-art in precision.

One approach involves the use of Shortwave Infrared (SWIR) imaging sensors for terminal guidance systems. For example, Goodrich ISR Systems in Princeton, N.J., is developing two-dimensional photodiode arrays that are sensitive from about 900 to 1700 nanometers -- the SWIR band -- which contains the majority of wavelengths for laser sources.

"That can be a 1 micron target designator, a 1.5 micron eye-safe laser, etc.," notes David G. Dawes, Goodrich's business development manager for U.S. Department of Defense (DOD) applications. "We also can extend that to shorter wavelengths, down to 700 nanometers, via a special process that gives us the ability to capture near-IR, most importantly the 850 nanometer laser pointers used by most weapons aiming sights.

"So an imaging sensor can see and confirm where designators are targeting; at present, most systems have a 'point-and-pray' mode of operation -- praying they hit the right target. To get confirmation you are on target, you need to see the laser spot; our sensor is one of the few that can do that. It also could be used defensively, to determine if you are being lased for a missile launch."

Lighter weight, ultra-sensitive imaging sensors also may enhance the capabilities of UAVs for intelligence, reconnaissance and surveillance (ISR) missions, enhance the targeting capabilities of weaponized UAVs or, eventually, become part of a precision-guided munition seeker.

Lightweight imaging sensors

"It's all about discrimination and positive ID of targets, especially in an urban theater of operations. Having seekers that can discriminate and track targets with better precision is the direction we're going -- and imaging sensors are the key enablers for that effort," Dawes says. "And the key enablers for those sensors mean being able to see targets in all kinds of environments and weather conditions, with all the contextual clues you really need for good identification rather than just detection.

"SWIR has advantages in having an intuitive visible light quality -- the image it produces is similar to what you would get in the visible arena, based on reflected light. Thermal images are based on emitted light from objects themselves and you lose all the details of surface texture needed to really identify an object as a specific target. And, on top of all that, you have the ability to see lasers. All of this is in a compact 90g package, with smaller ones in development with higher resolution."

Goodrich also is involved in a DARPA program called Dual-Detector Ensemble (DuDE), which uses a SWIR focal plane on which a microbolometer long-wave detector layer has been deposited.

"The bottom layer is an InGaAS (indium-gallium-arsenide) shortwave IR and the top layer is a microbolometer focal plane. This is a sensor that can simultaneously image shortwave and long-wave IR bands," Dawes says. "That gives you the best of both worlds -- the thermal sensor's ability to detect targets when there is no light available and the shortwave sensor's ability to positively ID targets and add contextual clues.

"It could be used in a range of applications, from a sniperscope to an ISR UAV to a PGM. DuDE is a next generation sensor that will be in development for the next five years, providing what I think is the key in precision strike -- positive identification. If you are not 100 percent sure the target you have in your sights is the right target, I don't think that qualifies as precision strike."

Smart artillery rounds

Precision guidance technologies already have turned traditional area suppression weapons into precision or near-precision munitions. One example is Excalibur, a GPS-guided artillery projectile extending the range and accuracy of current and future 155 mm howitzers. Another is development of the Army's Precision Guidance Kit (PGK), which replaces the fuse in the nose of conventional 155 mm artillery, essentially doing for artillery rounds what the Air Force Joint Direct Attack Munition (JDAM) did for "dumb" bombs.

"PGK provides accuracy for the Army requirement of a 50 meter CEP (Circular Error Probable) throughout all ranges, depending on the particular round being fired," says Dave Dorman, vice president of business development & strategy at Alliant Techsystems' (ATK) Advanced Weapons Division in Plymouth, Minn. "The norm is about 175 meters at 20 kilometers, so we have dramatically increased the accuracy of the round. At 30 kilometers, the normal dispersion is 273 meters with a rocket-assisted projectile and we would put a 50-meter accuracy on that at the same range, as well."

The Project Manager-Combat Ammunition Systems (PM-CAS) within PEO-Ammo is responsible for many current and future developments in precision weapons for the Army. And the Army Armament Research and Development Center's (ARDEC) Munitions Engineering Technology Center (METC) at Picatinny Arsenal, N.J., deals with current and new generations of PGK and Excalibur, as well as the Advanced Precision Mortar Initiative (APMI -- GPS guidance for 120mm mortars) and the Very Affordable Precision Projectile (VAPP) to increase ground force precision strike.

"The rules of engagement are pushing our direction for precision, as is the broader use of precision. We want to reduce collateral damage; we need precision for force protection of both friendlies and non-combatants; we're looking at scalable lethality, from non-lethal to lethal responses," says Bill Smith, METC's director for fuse & precision technologies. "All of that will push our targeting needs and the state-of-the-art in target locating devices; it also means smaller munitions and so smaller precision components."

Smart power for smart weapons

How to power new generations of precision-guided munitions -- and ensure long shelf life between combat requirements -- is a growing concern, especially given the push toward smaller systems to allow for larger explosives within a given munition size.

"A lot of precision munitions have needed to rely on thermal batteries, which are fairly large, to meet current demands to fit on the shelf for 10 to 15 years, then provide a massive current draw for a few seconds," notes Pete Burke, acting deputy product manager-mortars, PM-CAS. "So we have been investing in improvements in the chemistry of those. But we've also looked at energy harvesting devices, such as oscillating masses; for example, a spring that would oscillate, like a flashlight you shake to initiate a charge, but tuned to the vibration you would expect from gun launch shock."

The evolution of new technologies has, in many ways, changed what defines a precision weapon. For the first quarter of the 21st Century, the military is looking not only for weapons that can hit a specific small target, but do so with variable levels of lethality; that can be redirected -- or even terminated -- in-flight; can be used in any environment, with or without GPS; can use electronics to change the shape of an explosion, which also requires precise timing of the detonation.

"Precision gives you flexibility to tailor warhead effects to what you want. If you know exactly where the warhead will land, you can have a much smaller blast effect and so avoid collateral damage," ATK's Dorman says.

Precision also may play a larger role in smaller applications in the future, although each such advance will need to be considered on a cost-benefit basis.

"Miniaturization will afford the opportunity to get precision into smaller and smaller munitions, bringing a more direct effect to the individual warfighter -- so much so that having precision in 40mm rounds is not too far away," Smith says. "However, precision is more expensive and, as you deliver more rounds, it's a tradeoff between how many dumb bullets do you need on target versus precision rounds and what is the total cost of that change."

Smart munitions commonality

Some cost savings also may come from a push toward commonality across munitions.

"Even though we may not achieve everything the first time out of the box, all the component and GPS providers know everything should work for a 155, 105, and even an 81 millimeter munition," notes Paul Manz, Chief-Advanced Systems at PM-CAS. "Commonality then drives you to the smallest form factor and harshest environment, with a balance of performance and cost."

In the end, the future of precision guidance -- precision strike -- is a combination of many factors that not only use, but also direct technological evolution and revolution.

"There is kind of a metatrend in navigation -- the democratization of high-end technologies into a broader set of applications. In this case, doing what had been reserved for high-end systems on smaller munitions available in greater numbers," Lowell concludes. "DARPA really has been pushing the development of a broad range of these technologies into newer and many, many different applications.

"The PINS program really is not about a specific targeted point, but rather the development of an underlying technology that is a key aspect of the future of precision navigation. And the idea of moving precision

navigation to be better and more broadly used is really the cornerstone of the agency's investment for a long time now. It has enabled the technologies in use today -- and those coming in the foreseeable future."

Dugan cited the example of the “HALO” project for collecting airborne sensor data, which has cut dramatically the time required for aircraft to survey the landscape in Afghanistan, and had a direct impact on the ability of military pilots to find safe places to land.

Ultimately, that operational improvement has boiled down to the development of more sensitive detectors operating in the short-wave infrared (SWIR) spectrum. Now sensitive to just ten photons, rather than hundreds or thousands, much faster image capture has been enabled.

RedXDefense® Technology

At RedXDefense, we believe that explosives detection should be simple, fast, and affordable. We believe that users in the field need a system designed to be rugged, one that can be dropped or thrown in the back of a jeep, one that is unstopped by dirt and weather, one that is ready in 90 seconds with no warm up or calibration, one that is easily maintained.

Deployed since 2007, the XPAK is in use by foreign and U.S. Military, civilian, and private sector customers. Example applications include force protection, vehicle check points, clearance of unattended packages or cargo, and as a complement to canines. To date, the XPAK has had outstanding performance even in austere field environments such as Iraq and Afghanistan. Arguably, it has the most

field ‘up time’ of any trace explosives detection device available today.

RedXDefense employs an optical approach to explosives sensing, using fluorescent detection technology originally developed by the University of California, San Diego, and subsequently advanced by RedXDefense.  The optimized technology simultaneously detects trace levels of conventional high explosives, including TNT, DNT, RDX, PETN, HMX, Semtex, Tetryl, C4, PE -4, COMP B, Deta sheet, Prima sheet, Det cord, Prima cord, Picric Acid, TNB, DNB,Nitroglycerin, and the NEW HME capability: Urea Nitrate, Ammonium Nitrate, Ammonium Nitrate/Fuel Oil and TATP.

The proprietary fluorescent detection ink glows blue under UV light, but appears dark in the presence of explosives.  Thus trace explosives can be easily visualized as dark spots against the blue background of the ink.  The simple optical technique allows for simplified engineering into easy-to-use, intuitive detection devices that do not require warm-up time, calibration, or lengthy decontamination procedures.

RedX has purposefully designed explosive detection products, such as the XPAK® and XPAK-i and continue to develop innovative technologies as new threats emerge.

RedXDefense has an aggressive Intellectual Property development program. RedX’s team of professionals has extensive experience in IP portfolio management, development, and licensing.

In addition to a world-wide exclusive license with the University of California, San Diego, RedX has four issued patents and six original patents pending, covering innovative product designs and advances in the detection technology. This diverse portfolio provides the foundation for RedX's pioneering approach to the detection of trace explosives and offers advantages in ruggedness, throughput, cost, reliability, and packaging. Such advances enable widespread use in applications as diverse as military and first responder portable detection, transportation security, critical infrastructure and large venue protection, among others.

RedX’s team of scientists and engineers continue to advance this and related technologies.

The next generation XPAK G2.

In response to the persistent worldwide IED problem, RedX has developed the next generation XPAK G2with expanded range of explosives detection capability. The list of detectable explosives now includesHME (Homemade Explosives) making the XPAK G2 an effective tool in combatting IEDs. Call us for a demo today.

Darpa’s Butterfly-Inspired Sensors Light Up at Chem Threats

The Pentagon’s got a new game plan to detect deadly chemical threats: tiny, iridescent sensors that are designed to mimic one of nature’s most colorful creatures.

It’s the latest in a series of Darpa-funded efforts to use insects to spot weapons. Last year, the agency tapped researchers at Agiltron Corporation to implant larvae with micromechanical chemical sensors. In 2005, Darpa-backed scientists started training honey bees to become bomb sniffers.This time, Darpa’s interested in the chemical-sensing talents of butterflies. The agency’s awarded $6.3 million to a consortium, led by GE Global Research, that’ll develop synthetic versions of the nanostructures found on the scales of butterfly wings.

The project’s lead researcher, Dr. Radislav Potyrailo, likens the nanostructures on the butterfly wing scales, which each measure around 50 by 100 microns, to “tiles on a roof.” The science of chemical response behind the structures is based on photonics. The wings of Morpho butterflies change spectral reflectivity depending on the exposure of the scales to different vapors. As Potyrailo and his team write in a 2007 paper, published in Nature Photonics, “this optical response dramatically outperforms that of existing nano-engineered photonic sensors.”

“This is a fundamentally different approach,” he tells Danger Room. “Existing sensors can measure individual gases in the environment,

but they suffer, big time, from interferences. This approach overcomes that hurdle.”

A single sensor would be tailored to detect certain types of chemical agents or explosives, and do so without hindrance from other chemicals, airborne molecules or even humidity. Water molecules, Potyrailo points out, can overload a dangerous gas that’s sparsely distributed but “is still able to have actionable effects in a military setting.” And, much like their biological inspiration, the sensors would do the job with remarkable specificity.

“It would be science fiction to say ‘here is my sensor, it can selectively detect 1,000 different chemicals’,” he says. “But what we’re saying is that we can detect and distinguish between several important chemicals — without making mistakes, without false responses.”

At around 1 x 1 cm apiece, the sensors are also small enough to be attached to clothing, installed in buildings or deployed “like confetti” over widespread regions. And they’d have helpful civilian uses, as well, from food safety and water purification tests to emissions monitoring at power plants. So be careful, the next time you swat an insect. It just might save your skin.

Collaboration of GE Global Research, Air force research laboratory, University at Albini, University of Exeter

Team Members: Dr. Helen Ghiradella, from State University at Albany, an expert on the biology of structural color; Dr. Peter Vukusic, from the University of Exeter, an expert on the physics of structural color; Dr. Rajesh Naik, from the Air Force Research Laboratory, with a strong background in bio-inspired functional materials and surface functionalization; and Dr. John Hartley, also from State University at Albany, specializing in advanced lithographic nanofabrication.

These team members will complement GE’s strong multidisciplinary team of analytical chemists, material scientists, polymer chemists, optical engineers and nanofabrication engineers who are contributing to development of this new platform.

Darpa Looks to Upgrade Bio-Threat Detectors By Katie Drummond   October 19, 2009  |  5:28 pm  |  

Infectious microorganisms are on the rise, and the Pentagon’s on a mad dash for better detection, treatment and even all-out prevention. With a need for turbocharged response, it’s no surprise that Darpa, the military’s mad-science division, is playing a major role in combating bioterror attacks and natural threats like H1N1.

Now the agency’s requesting proposals for a device that would enable faster, more accurate detection of a broad range of biological agents. The Antibody Technology Program hopes to create a biosensor that would identify viral and bacterial threats, and do so using a natural first-line of defense: human antibodies.

This isn’t the first time Darpa’s asked for better, more versatile microorganism detectors. In 2002, they launched the Biosensors Technology Program [pdf], to figure out the fastest, most effective way to detect a wide array of bio-agents with a single device. Among the contenders were mass spectrometry, a technique to separate and identify molecules based on mass, and hand-held nucleic acid sensors, which would analyze the DNA and RNA of potentially dangerous substances. According to Darpa’s new solicitation, antibody biosensors offered the most reliable detection, across the broadest range of bio-agents. And now, they want to make the sensors even better.

Darpa’s asking for proposals that would address the two downsides of antibody-based biosensors. Antibody proteins are fragile, so they’re unable to withstand extreme temperatures or survive longer than a few weeks in storage. That’s hardly practical for civilian medical centers, let alone a war-zone. Darpa wants the new biosensors to be as resilient as possible. They’re asking for molecular manipulation of the antibodies, so that the biosensors will be stable for five years, and work at temperatures that range from 25 to 70 degrees Celsius (77 to a sweltering 158 degrees Fahrenheit).

When they haven’t been tinkered with in a lab, antibodies are produced by the body in reaction to a foreign viral or bacterial threat, called an antigen. A particular antibody can only bind to a single antigen, but science has already created antibodies that can bind to several different ones. Now, Darpa wants them to have even an more diverse “affinity level”: the ability to bind to a potentially endless array of viral or bacterial antigens. The tip of an antibody is extremely variable, which is why different antibodies attach to different antigens. It’s this binding that’s used by biosensors to identify various microorganisms, and distinguish between them. Darpa wants to control, or “fine-tune” antibody affinity, so that one “master antibody” can bind with millions of antigens.Darpa’s request isn’t specific about how they expect the master antibody, and it’s accompanying biosensor, to be created. But artificial antibodies have been in-the-making for years, offer a cheaper, more easily manipulated platform, and are becoming more reliable thanks to new technology. Plus, researchers at Portland State University have already manufactured a hand-held antibody biosensor, so chances are good that the detection of biothreats will look cooler than a throat swab, too.

Army Seeks Super-Sniffer to Detect Explosives, Bio-AgentsCoverage of the new technology of metamaterials   has tended to focus on the possibility of a real-life invisibility cloak. That kind of application is a long way off, but in the much shorter term the Army is developing new materials to build an ultra-sensitive sensor capable of detecting the faintest trace of a scent: a nose like no other.No artificial sensor has ever been able to match the sensitivity of, say, a sniffer dog. But that might change if a research effort by the US Army’s Aviation and Missile Research Development and Engineering Center   (AMRDEC) comes to fruition. This is based on the technology of plasmonics, which involves capturing light waves.What does light have to do with sniffing? This particular super-sniffer would be based on Surface Enhanced Raman Spectroscopy (SERS). As with other types of spectroscopy, it allows a substance to be analyzed by looking at the spectrum of light coming off it. Normally you need a large amount of the material in order to get a reading, but in SERS the scattering effect is boosted. The right shape of micro-

structure can capture photons, trapping them as surface waves known as plasmons. These plasmons will interact with specific molecules and hugely increase the scattering effect, so that a tiny sample is needed. Under the right conditions, this technique is hundreds of millions of times more sensitive than it would be without the surface effect.SERS means a detector can pick up the tiniest traces of a substance in the air; in theory, one could detect a single molecule. Sound outlandish? Nature already has sensors this good: a male silkworm moth can detect a single molecule of scent   released by a female .

Some SERS detectors already exist, but the technology is in its infancy and the underlying physics is not well understood. Early work used a simple roughened surface to capture plasmons, but AMRDEC would take the technology to a new level by the precise fabrication of a metal surface. Computer modeling is used to determine an effective shape, and this is then created by drilling very precise microscopic holes in metal foil using a beam of high-energy ions. This image – a view magnified 20,000 times — illustrates.

What is the potential application? In the first instance, AMRDEC want novel detectors to detect bacteria and chemical warfare agents. Unlike a dog, a detector can tell you which specific agent it can sense. Other possible applications might include spotting explosives from a distance — warning of the presence of a booby trap, car bomb or suicide vest. The same technology could be used to detecting smuggled drugs or airborne pollutants.

The AMRDEC team is still evaluating how effective their different designs are for plasmon-trapping material. Once this is completed, they will then be able to integrate it into a sensor. It may not be as glamorous as an invisibility cloak, but a new ultra-sensitive sniffer might be just as useful for saving lives

DARPA Eyes Thermal Sensors for Cell PhonesThe technology research arm of the Department of Defense (DoD) is eyeing the development of high-performance thermal-sensing

imaging technology that can be used on devices as small as cell phones and PDAs.

For musicians, podcasters, voice over artists, the iRig Microphone is an excellent mobile recording companion for the iPhone, iPod Touch and iPad.

The Defense Advanced Research Projects Agency (DARPA) is seeking proposals for its Low Cost Thermal Imager Manufacturing (LCTI-M) program, which aims to develop inexpensive thermal cameras soldiers can use in the field to increase their visibility within short distances in all weather conditions, according to a request for proposals the agency posted on FedBizOpps.gov.This type of technology will address a "key shortfall" in current intelligence, surveillance, and reconnaissance systems the DoD has: "the lack of a thermal imaging capability available for each warfighter and adequate [infrared] camera form-factors suitable for using with network-enabled small sensor platforms," according to the RFP.

DARPA has very specific size, feature, and cost requests for the technology it plans to develop, according to the RFP. It wants to create wafer-scale optics that can be mass produced to keep the cost down and allow for the use of the sensors in small form factors.At the same time, the quality of the images the sensors produce must be high. The cameras must not only be able to detect an "upright, stationary adult human being" at close range, but also whether that person poses a threat to the soldier with a weapon, according to the RFP.With these features, the cost for the cameras should still be less than $500, a figure that includes recurring and non-recurring costs related to camera production, according to the RFP.Firms have until March 9 to respond to DARPA's RFP for the LCTI-M program. To be considered for the work, they will have to produce prototypes of the cameras and their core technology, according to the RFP.The military has expressed keen interest lately in creating more personalized technology for soldiers, particularly through the use of handheld devices they keep with them during combat. For example, the Army is deploying smartphones to soldiers loaded with applications that will help them perform better in both the classroom

and the field through a program called Connecting Soldiers to Digital Applications.

DARPA, Lockheed Martin develop sensor system that uses gravity to locate, identify underground targets

By Andrew Nusca | July 19, 2010, 7:42 AM PDT

The Pentagon’s research division, DARPA, has commissioneddefense contractor Lockheed Martin to develop a sensor system that can locate and identify underground targets — with a little help from gravity.The prototype sensor and system is for DARPA’s Gravity Anomaly for Tunnel Exposure, or GATE, program. The mission? To “detect, classify, and characterize subterranean threats such as tunnels, bunkers, and caches.”

At the center of the sensor system is a gravity gradiometer, which measures tiny variations in gravitational forces. By detecting variations, the sensor can identify a man-made void from naturally-occurring topographical features.In other words: a near real-time map of what’s underground from an airborne vehicle.

“Our expertise in gravity gradiometers will help increase the capability to detect and characterize subterranean tactical threats by its anomalous gravity signature,” said James Archibald, general manager of Lockheed’s New York-based Niagara Operation, in a

statement. “This capability will help prevent both underground infiltration of secure perimeters and tactical underground operations, keeping our assets and troops protected.”

Gravity gradiometers have previously been used to explore natural resources, particularly those underground. Variations in density hint at geologic structures that may reveal a simply void — or a deposit of ore, oil or gas that’s of interest to energy firms in search of the next hydrocarbon cache.

Lockheed Martin will develop the sensor and system’s conceptual design in a 12-month contract. If it’s to DARPA’s liking, Lockheed will be contracted for 18 months to produce a prototype system.

[via Danger Room]Illustration: Lockheed Martin

DARPA awards Georgia Tech $4.3m to develop biochemical sensors

10 Dec 2010

The US Defense Advanced Research Projects Agency (DARPA) has awarded the Georgia Institute of Technology $4.3m to develop a new class of sensors able to detect multiple biological and chemical threats simultaneously.

 Using integrated photonics, the new class of sensors will be capable of detecting chemical agents, such as toxins, pollutants and trace gases, and biological agents, such as proteins, viruses and antibodies, simultaneously on the same chip.

The sensors will have applications in clinical screening, drug discovery, food safety, environmental monitoring and national security.

“The proposed sensors will detect multiple biological and chemical threats on a compact integrated platform faster, less expensively and more sensitively than the current state-of-the-art sensors,” said Ali

Adibi, a professor in the School of Electrical and Computer Engineering at Georgia Tech.

The Defense Advanced Research Projects Agency (DARPA) is funding a two-year $4.3 million center as one of its Centers in Integrated Photonics Engineering Research (CIPhER), which investigate innovative approaches that enable revolutionary advances in science, devices or systems.

For its center, Georgia Tech is working with researchers from Emory University; Massachusetts Institute of Technology; University of California, Santa Cruz; and Yale University. The team also includes industry collaborators Rockwell Collins, Kotura, Santur Corporation and NanoRods.

To create an integrated chip that will simultaneously detect multiple biological and chemical agents, the researchers need to achieve three major goals:

design and fabricate photonic and optomechanical structures to sense differences in a sample’s refractive index, Raman emission, fluorescence, absorption and mass;

functionalize the sensor surface with coatings that chemical and biological agents will attach to and create differences that can be detected; and

develop the sample preparation method and microfluidic sample delivery device, and connect the device to the coated photonic structure.

Adibi is leading the first thrust, which is primarily focused on fabricating the millimeter-square sensing structures and on-chip spectrometers that will enable multiplexing — the detection of multiple agents using the same sensing modules.

The sensors will detect changes in the refractive index, Raman emission, fluorescence, absorption spectra and optomechanical properties when a sample that includes specific biological or chemical particles interacts with the sensor coatings. Combining information obtained from the five different sensing modalities will maximize the sensor specificity and minimize its false detection rate, the researchers say.

“The goal is to achieve very high sensitivity for each modality and investigate the advantages of each modality for different classes of biological and chemical agents in order to develop a clear set of guidelines for combining different modalities to achieve the desired performance for a specific set of agents,” explained Adibi.

Massachusetts Institute of Technology chemistry professor Timothy Swager is leading the second part of this project, which aims to design surface coatings that will achieve maximum sensor specificity in detecting multiple biological and chemical agents.

“We plan to develop glycan-based surface coatings to sense biological agents and polymer-based surface coatings to sense chemical agents,” noted Adibi.

For the third thrust, which is being led by Massachusetts Institute of Technology electrical engineering associate professor Jongyoon Han, the researchers will develop optimal sample preparation and delivery techniques. Their goal is to maximize the biological or chemical particle concentration in the sample and limit detection time to minutes.

“In two years, we hope to have a lab-on-a-chip system that includes all of the sensing modalities with appropriate coatings and microfluidic delivery,” said Adibi. “To show the feasibility of the technology, we plan to demonstrate the high sensitivity and high selectivity of each sensor individually and be able to use at least two of the sensing modalities simultaneously to detect two or three different chemical or biological agents.”

 

Millimetre Wave and Terahertz Sensors and Technology III, Keith A. Krapels;Neil A. Salmon, Editors, 783703

Date: 8 October 2010

Paper Abstract

Millimeter-wave monolithic integrated circuit (MMIC) technology is now widely recognized as a key to many modern applications in safety and security, ranging from

near and far-field imaging and sensing to non-invasive material inspection. In this paper, we apply our state-of-the-art MMIC technology to the analysis of gaseous media by spectroscopic techniques. The paper presents recent developments of amplifying and frequency-translating MMICs based on metamorphic HEMT technology and their application to the spectroscopic analysis of the frequency range from 250 to 330 GHz, including the important absorption line of water around 321 GHz.

THz imaging with low-cost 130 nm CMOS transistors (Proceedings Paper)

Millimetre Wave and Terahertz Sensors and Technology III, Keith A. Krapels;Neil A. Salmon, Editors, 783704

Date: 20 October 2010

Paper Abstract

We report on active imaging with CMOS transistors at 300 GHz and 1.05 THz. Two basic focal plane arrays consisting of nMOS transistors and wide-band bow-tie antennas have been implemented in a low-cost 130 nm CMOS technology. Raster scan imaging of objects concealed in a paper envelope has been achieved at 300 GHz with a commercial radiation source. The images clearly reveal the concealed objects with a dynamic range of 35 dB and a resolution of 3 mm. At 1.05 THz, the pixels achieve a responsivity of 50 V/W and a noise equivalent power of 900 pW/Hz0.5.

Light Sensor Breakthrough Could Enhance Digital CamerasScienceDaily (June 22, 2009) —  New research by a team of University of Toronto scientists could lead to substantial advancements in the performance of a variety of electronic devices including digital cameras.

See Also:Matter & Energy Optics Technology Energy Technology

Computers & Math Photography Computer Graphics Mobile Computing

Reference Webcam MRAM Semiconductor

Quantum dot

Researchers created a light sensor – like a pixel in a digital camera – that benefits from a phenomenon known as multi-exciton generation (MEG). Until now, no group had collected an electrical current from a device that takes advantage of MEG."Digital cameras are now universal, but they suffer from a major limitation: they take poor pictures under dim light. One reason for this is that the image sensor chips inside cameras collect, at most, one electron's worth of current for every photon (particle of light) that strikes the pixel," says Ted Sargent, professor in U of T's Department of Electrical and Computer Engineering. "Instead generating multiple excitons per photon could ultimately lead to better low-light pictures."In solar cells and digital cameras, particles of light - known as photons - are absorbed in a semiconductor, such a silicon, and generate excited electrons, known as excitons. The semiconductor chip then measures a current that flows as a result. Normally, each photon is converted into at most one exciton. This lowers the efficiency of solar cells and it limits the sensitivity of digital cameras. When a scene is dimly lit, small portable cameras like those in laptops suffer from noise and grainy images as a result of the small number excitons."Multi-exciton generation breaks the conventional rules that bind traditional semiconductor devices," says Sargent. "This finding shows that it's more than a fascinating concept: the tangible benefits of multiple excitons can be seen in a light sensor's measured current."The research was supported by grants from the King Abdullah University of Science and Technology, the Natural Sciences and Engineering Research Council of Canada, the Canada Research Chairs, and the Canada Foundation for Innovation and the Ontario Innovation Trus

U of T research holds promise for optical chip

University of Toronto researchers have developed a hybrid plastic that can produce light at wavelengths used for fibre-optic communication, paving the way for an optical computer chip.

The material, developed by a joint team of engineers and chemists, is a plastic embedded with quantum dots - crystals just five billionths of a metre in size - that convert electrons into photons. The findings hold promise for directly linking high-speed computers with networks that transmit information using light - the largest capacity carrier of information available.

"While others have worked in quantum dots before," says investigator Ted Sargent, a professor in the Edward S. Rogers Sr. Department of Electrical and Computer Engineering, "we have shown how quantum dots can be tuned and incorporated into the right materials to address the whole set of communication wavelengths.

"Our study is the first to demonstrate experimentally that we can convert electrical current into light using a particularly promising class of nanocrystals," says Sargent, who holds the Nortel Networks-Canada Research Chair in Emerging Technologies. The study appears in the April 28 issue of the journal Applied Physics Letters.

"Our research is based on nanotechnology: engineering based on the length of a nanometer - one billionth of a metre," he says. "We are building custom materials from the ground up." Working with colleagues in Professor Gregory Scholes' group from U of T's Department of Chemistry, the team created nanocrystals of lead sulphide using a cost-effective technique that allowed them to work at room pressure and at temperatures of less than 150 degrees Celsius. Traditionally, creating the crystals used in generating light for fibre-optic communications means working in a vacuum at temperatures approaching 600 to 800 degrees Celsius.

Despite the precise way in which quantum dot nanocrystals are created, the surfaces of the crystals are unstable, Scholes explains. To stabilize them, the team placed a special layer of

molecules around the nanocrystals. These crystals were combined with a semiconducting polymer material to create a thin, smooth film of the hybrid polymer.

Sargent explains that when electrons cross the conductive polymer, they encounter what are essentially "canyons," with a quantum dot located at the bottom. Electrons must fall over the edge of the "canyon" and reach the bottom before producing light. The team tailored the stabilizing molecules so they would hold special electrical properties, ensuring a flow of electrons into the light-producing "canyons."

The colours of light the researchers generated, ranging from 1.3 microns to 1.6 microns in wavelength, spanned the full range of colours used to communicate information using light.

"Our work represents a step towards the integration of many fibre-optic communications devices on one chip," says Sargent. "We've shown that our hybrid plastic can convert electric current into light, with promising efficiency and with a defined path towards further improvement. With this light source combined with fast electronic transistors, light modulators, light guides and detectors, the optical chip is in view."

The research team included Ludmila Bakueva, Sergei Musikhin, Margaret Hines, Tung-Wah Frederick Chang and Marian Tzolov from the departments of chemistry and electrical and computer engineering. The research was supported by Nortel Networks, the Natural Sciences and Engineering Research Council of Canada, Materials and Manufacturing Ontario, the Canada Foundation for Innovation, the Ontario Innovation Trust and the Canada Research Chairs Program.

###

CONTACT:

Ted SargentEdward S. Rogers Department of Electrical and Computer Engineering416-946-5051ted.sargent@utoronto.ca

Nicolle WahlU of T Public Affairs416-978-6974nicolle.wahl@utoronto.ca

New sensor can even detect TNT

Researchers from MIT have developed a sensor so precise that it can detect just a single molecule of an explosive, which could be useful for the military and certain commercial businesses. 

Michael Strano, study leader and Charles and Hilda Roddey Career Development Associate Professor of Chemical Engineering at MIT, along with Daniel Heller, lead author of the paper and former graduate in Strano's lab, and a team of chemical engineers,created the revolutionary sensor. 

Currently, explosives detectors that are used in airports, for example, utilize spectrometry to identify charged particles in the air. However, these detectors are not as sensitive as those developed in Strano's lab.

"Ion mobility spectrometers are widely deployed because they are inexpensive and very reliable," said Strano. "However, this next generation of nanosensors can improve upon this by having the ultimate detection limit, [detecting] single molecules of explosives at room temperature and atmospheric pressure." 

Strano and his team created the sensor using carbon nanotubes, which are hollow cylinders made of pure carbon. These carbon nanotubes are coated with protein fragments called bombolitins, which are normally found in bee venom. These carbon nanotubes have a natural fluorescence, and when a target binds to the protein fragments on the nanotubes, the fluorescent light's wavelength is shifted, which allows for easy detection. 

A previous study by Strano worked similarly. He had created carbon nanotube sensors that detect hydrogen peroxide, nitric oxide and nerve gas sarin. A molecule is used to bind to a specific target, and when the target is attached, the fluorescent light brightens or dims, changing in intensity rather than wavelength.  

The new sensors are a bit easier to use because they are not influenced by ambient light. According to Strano, using the intensity of fluorescent light to gauge whether a target is bound or not is more prone to errors than measuring wavelength. 

The new sensor is capable of detecting different explosives and even pesticides by using different nanotubes coated with different types of bombolitins because each nanotube-peptide duo reacts in a different way to nitro-aromatic compounds. 

"Compounds such as TNT decompose in the environment, creating other molecule types, and those derivatives could also be identified with this type of sensor," said Strano. "Because molecules in the environment are constantly changing into other chemicals, we need sensor platforms that can detect the entire network and classes of chemicals, instead of just one type." 

Strano and his team believe this new sensor could be beneficial for the military, commercial businesses like airports and environmental purposes like pesticide detection. But he noted that it is not quite ready for these applications yet.