Simple piezoresistive accelerometer

Transcription

1 Simple piezoresistive pressure sensor

2 Simple piezoresistive accelerometer

3 Simple capacitive accelerometer Cap wafer C(x)=C(x(a)) Cap wafer may be micromachined silicon, pyrex, Serves as over-range protection, ti and ddamping Typically would have a bottom cap as well.

4 Simple capacitive pressure sensor C(x)=C(x(P))

5 ADXL50 Accelerometer +-50g Polysilicon MEMS & BiCMOS 3x3mm die I i f Integration of electronics!

6 ADXL50 Sensing Mechanism Balanced differential capacitor output Under acceleration, capacitor plates move changing capacitance and hence output voltage On-chip feedback circuit drives on-chip force-feedback to recenter capacitor plates (improved linearity).

7 Analog Devices Polysilicon MEMS

8 ADXL50 block diagram

9 MEMS Gyroscope Chip Rotation induces Coriolis acceleration Proof Mass Sense Circuit Digital Output Electrostatic Drive Circuit J. Seeger, X. Jiang, and B. Boser

10 MEMS Gyroscope Chip J. Seeger, X. Jiang, and B. Boser

11 Two-Axis Gyro, IMI(Integrated Micro Instruments Inc.)/ADI (fab)

12 Single chip six-degree-of-freedom inertial measurement unit (uimu) designed d by IMI principals and fabricated by Sandia National Laboratories

13 TI Digital Micromirror Device

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16 NEU/ADI/Radant/MAT Microswitches p Surface Micromachined Post-Process Integration with CMOS V Electrostatic Actuation ~100 Micron Size Drain Gate Beam Source Beam Drain Gate Source Gate SEM of NEU microswitch Landing ring MEMS Seal ring Drain Source Feedthrough Microbump Dielectric Package Substrate MAT Microswitch

17 Contact End of Switch Contact Detail

18 Spectrometer cross-section Surface Micromachined Spring System Electrostatic Actuator Plates 9/11/2008

19 9/11/2008 Fabricated Microspectrometers

20 Intensity vs. Wavelength 1.2 λ =515 nm FWHM = 25nm RP = 21 λ = 575nm FWHM = 30nm RP = 20 λ =625nm FWHM = 39nm 1 RP = 16 In ntensity (arb b. units) Wavelength (nm)

21 Packaged Plasma Source Top View Die in Hybrid Package Side View

22 Fabrication PR Cr/Au/TiW Glass Wafer Expose/Dev. TiW etch Electroplate Gold PR strip TiW/Au/Cr etch spiral coil to vacuum system Bond to 10 mm diam. glass chamber interdigitated capacitor SEM of Interdigitated Capacitor Structure

23 Optical MEMS Vibration Sensors Uniform cantilever beam Foster Miller - Diaphragm Cantilevered paddle Cantilevered supported diaphragm

24 Optically interrogated MEMS sensors 55 µm length cantilevered paddle after 7 hours of B.O.E. releasing and lifted up with a 1µm probe (~0.35µm thick, 2µm gap)

25 Courtesy Connie Chang-Hasnain

26 Courtesy Connie Chang-Hasnain

27 Micromachining Ink Jet Nozzles Microtechnology group, TU Berlin

28 (UCLA, Fan)

29 (Gruning)

30 Gene chips, proteomics arrays.

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43 NEMS: TOWARD PHONON COUNTING: Quantum Limit of Heat Flow. Roukes Group Cal Tech Tito

44 From Ashcroft and Mermin, Solid State Physics.

45 Other: NSF-Funded NSEC, Center for High-Rate Nanomanufacturing (CHN): High-rate Directed Self-Assembly of Nanoelements Proof of Concept Testbed Nanotemplate: Layer of assembled nanostructures transferred to a wafer. Template is intended to be used for thousands of wafers. Nanotube Memory Device Partner: Nantero first to make memory devices using nanotubes Properties: nonvolatile, high speed at <3ns, lifetime (>10 15 cycles), resistant to heat, cold, magnetism, vibration, and cosmic radiation.

46 Switch Logic, 1996, Zavracky, Northeastern Inverter NOR Gate

47 Simple Carbon Nanotube Switch Diameter: 1.2 nm Elastic Modulus: 1 TPa Electrostatic Gap: 2 nm Binding Energy to Substrate: 8.7x10-20 J/nm Length at which adhesion = restoring force: 16 nm Actuation Voltage at 16 nm = 2 V Resonant frequency at 16 nm = 25 GHz Electric Field = 10 9 V/m or 10 7 V/cm + Geom. (F-N tunneling at > 10 7 V/cm) Stored Mechanical Energy (1/2 k x 2 )=4x10-19 J=25eV x = ½ CV 2 gives C = 2 x << electrode capacitance! Much more energy stored in local electrodes than switch.

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49 Biological Nanomotor