Microloading Effect

Demonstration of microloading effect where etch depth increases with trench width. Image is of 10 µm deep Si using RIE with Cl/ F chemistry.

Bosch process

Deep reactive ion etching (DRIE) using Bosch process enables high aspect ratio structures

Each cantilever is functionalized on one side with a different oligonucleotide base sequence (red or blue). (A) The differential signal is set to zero. (B) After injection of the first complementary oligonucleotide (green), hybridization occurs on the cantilever that provides the matching sequence (red), increasing the differential signal Delta x. (C) Injection of the second complementary oligonucleotide (yellow) causes the cantilever functionalized with the second oligonucleotide (blue) to bend.

Deflection-based sensors

Science 14 April 2000:Vol. 288. no. 5464, pp. 316 - 318

Array of cantilevers used as deflection sensors for chemical solvent vapors. Cantilevers are coated with different polymers in order to define a particular set of responses based on how each polymer responds to a given analyte.

Resonance-based sensors

Nanoscale gold dot can be used with thiol-based chemistries to localize analyte binding. This device is capable of detecting attogram quantities of thiol-terminated SAMs

Gold dot

2 um

SEM image of single E. coli bound on cantilever tip. This cantilever measured the mass of a single cell to be 665 fg

5 um

Nanostring resonator

Doubly-clamped nanomechanical resonator defined nonlithographicall where electrospun fibers are used as etch mask.

Cantilever Array

Arranging cantilever-based sensors into arrays allows detection of multiple analytes from a single sample

Resonance peaks from resonance-based sensors

Example of resonant peaks measured between reaction steps in the detection of virus particles.

Before and after virus-specific antibody layer depositionResonance peak after

virus binding