![Page 1: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/1.jpg)
Mirasol Displays
MAE 268
Erik Bettis
Josh Saylor
![Page 2: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/2.jpg)
Introduction
• MEMS device developed by Qualcomm– Low power display
• Uses ambient light as source• Operation requires very low voltages
– Replacement for current LCD screens• Cell phones and other small devices
– Enhance viewability in direct light• Brightness of display increases as ambient light
intensifies• Light reflection of up to 50%
Erik Bettis
![Page 3: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/3.jpg)
Current Products
Inventec V112 Smartphone
G-Core Mini Caddy
Hisense C108 Handset
Erik Bettis
![Page 4: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/4.jpg)
Mirasol Technology
• Interferometric Modulation (IMOD)• Low power consumption• Increased readability in direct light• Bistability
– Hysteresis– Built in Memory
• Pixels– Color Generation
• Interference• Spatial Dithering
Erik Bettis
![Page 5: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/5.jpg)
Interfermetric Modulation(IMOD)• Enables reflective, direct view and flat panel
displays• Refresh rates on the order of microseconds
– Video-rate capable• Contrast Ratio: >15:1• Reflectivity: ~ 50%• Wall Street Journal
– Contrast Ratio: 4:1– Reflectivity: ~ 60%
Erik Bettis
![Page 6: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/6.jpg)
Power Metrics
• Mirasol IMOD Display vs. TFT LCD Displays
Video Time Typical Use Multi Media Use
4.5 Hours 206 min 160 min
3.3 Hours 70 min 24 min
Erik Bettis
![Page 7: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/7.jpg)
Increased Readabilty
Erik Bettis
![Page 8: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/8.jpg)
What is Bistability?
• Main feature of Mirasol devices that allows for low power consumption.
• Allows for pixels to be left on or off with near-zero power drain.– Uses imbalance between electro-mechanical
forces and mechanical forces to hold membrane in place with very low power.
• Provides built in memory for pixel placement
Erik Bettis
![Page 9: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/9.jpg)
Hysteresis
• Stage 1– Constant bias voltage holds membrane in open state
• Stage 2– Positive pulse applied to drive membrane into
collapsed state• Stage 3
– Constant bias voltage holds membrane in collapsed state
• State 4– Negative pulse applied to snap membrane back to
open position
Erik Bettis
![Page 10: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/10.jpg)
Bistability and Hysteresis in Mirasol
Erik Bettis
![Page 11: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/11.jpg)
Pixel Design and Color Generation• Pixels create patterns of Red, Green and Blue to create 256k
color range– Interference
• Reflects different wavelengths to create different colors– Red: λ = 675 nm– Green: λ = 520 nm– Blue: λ = 450 nm
– Dithering• Meshes different amounts of Red, Green and Blue to create
new colors– Similar to mixing paint colors on the nano-scale
Josh Saylor
![Page 12: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/12.jpg)
Examples of Spatial DitheringColor perceivedColors as Assigned
Josh Saylor
![Page 13: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/13.jpg)
Interference
Josh Saylor
![Page 14: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/14.jpg)
Side Profile
Thin Film ElectrodeGlass
Spring Analog operating region (225 nm)
Rigid SiO2 Support
Mirror
50 μm
(not to scale)
Pull in distance (450 nm)
Si substrate
Advantage: Analog mirror control allows for multiple colors from a single unit
Blue: 450 nmGreen: 520 nmRed: 675 nm
Proposal of New Design
Josh Saylor
![Page 15: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/15.jpg)
Spring Material
Spring can easily be machined by standard surface micro-machining procedures
SiO2 Support
Compressible Design
0 V
Spring Fabrication
Josh Saylor
![Page 16: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/16.jpg)
Values Used
Max Voltage = 5 V
Permittivity = ε0 = 8.85x10-12 F/m
Area = (50 μm)2 = 2.5x10-9 m2
Initial spacing = 675 nm
k = Fpull-in / Δxspring = 6.1 N/m
Fpull-in = = 1.4x10-6 N
Vpull-in = = 5 V
Mirror will collapse against thin film at
5 Volts
Pull In Voltage and Spacing
Josh Saylor
![Page 17: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/17.jpg)
Current Design42 units per pixelOne color per unit
New Design4 units per pixel
350 μm100 μm
Resolution Scaling Factor of 10
The old 1.4 inch display with 176 x 144 resolution
would increase to 1760 x 1440 pixels with new design
Temporal and Spatial
dithering still possible
Pixel Design of New Layout
Josh Saylor
![Page 18: Mirasol Displays MAE 268 Erik Bettis Josh Saylor](https://reader031.vdocument.in/reader031/viewer/2022012914/56649e535503460f94b48957/html5/thumbnails/18.jpg)
Questions