Simple piezoresistive pressure sensor · 2008. 9. 11. · Simple piezoresistive pressure sensor....
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Simple piezoresistive pressure sensor sensor
Transcript of Simple piezoresistive pressure sensor · 2008. 9. 11. · Simple piezoresistive pressure sensor....
Simple piezoresistive pressure sensorsensor
Simple piezoresistive accelerometer
Simple capacitive accelerometerC(x)=C(x(a))
Cap waferCap wafer
C f b i hi d ili• Cap wafer may be micromachined silicon, pyrex, …S t ti d d i• Serves as over-range protection, and damping
• Typically would have a bottom cap as well.
Simple capacitive pressure sensorC(x)=C(x(P))
ADXL50 Accelerometer
• +-50g• PolysiliconPolysilicon
MEMS & BiCMOSBiCMOS
• 3x3mm dieI i f• Integration of electronics!
ADXL50 Sensing Mechanismg• Balanced differential capacitor output• Under acceleration, capacitor plates move changing
capacitance and hence output voltagecapacitance and hence output voltage• On-chip feedback circuit drives on-chip force-feedback to re-
center capacitor plates (improved linearity).
Analog Devices PolysiliconAnalog Devices Polysilicon MEMS
ADXL50 – block diagram• http://www.analog.com/en/mems-and-sensors/imems-accelerometers/products/index.html
MEMS Gyroscope Chip
SenseProof
Digital OutputSense
CircuitProof MassRotation
induces Coriolis
l ti
Electrostatic
acceleration
Drive Circuit
J. Seeger, X. Jiang, and B. Boser
MEMS Gyroscope ChipMEMS Gyroscope Chip
J. Seeger, X. Jiang, and B. Boser
Two-Axis Gyro, IMI(Integrated Micro Instruments Inc.)/ADI (fab)
Single chip six-degree-of-freedom inertial i ( IMU) d i d b IMImeasurement unit (uIMU) designed by IMI
principals and fabricated by Sandia National Laboratories
TI Digital Micromirror Deviceg
NEU/ADI/Radant/MAT Microswitcheshttp://www.radantmems.com/radantmems/switchoperation.html
Gate
p p
Surface MicromachinedPost-Process Integration with CMOS20 100 V El i A i
Drain SourceBeam20-100 V Electrostatic Actuation~100 Micron Size
Beam
Drain Gate Source
Beam
SEM of NEU microswitchGate
Seal ringLanding MEMS
Drain Source Feedthrough Dielectric
ring
Microbump
Landingring
Package Substrate
MEMS
MAT Microswitch
Contact DetailContact End of Switch
Spectrometer cross-section
Surface MicromachinedSpring System
ElectrostaticActuator Plates
9/11/2008
Fabricated Microspectrometers
9/11/2008
Intensity vs. Wavelength
λλ 515515 λ λ = 575nm= 575nm
1
1.2λλ =515 nm=515 nm
FWHM = 25nmFWHM = 25nm
RP = 21RP = 21
λ λ 575nm 575nm
FWHM = 30nmFWHM = 30nm
RP = 20RP = 20λλ =625nm=625nm
FWHM = 39nmFWHM = 39nm
RP = 16RP = 16
0.8
b. u
nits
)
0.4
0.6
nten
sity
(arb
0.2
In
0450 500 550 600 650 700 750
Wavelength (nm)
Packaged Plasma SourceTop View
Die in Hybrid Package
Side ViewSide View
Fabrication
PRPR
Glass WaferCr/Au/TiW
Expose/Dev.TiW etch
ElectroplateGold
PR stripTiW/Au/Cr etch
Bond to 10 mm diam.glass chamberspiral coil
SEM of Interdigitated glass chamberspiral coil
interdigitated capacitor
to vacuum system
Capacitor Structure
Optical MEMS Vibration SensorsOptical MEMS Vibration Sensors
Uniform cantilever beam Foster Miller - Diaphragm
Cantilevered paddle Cantilevered supported diaphragm
Optically interrogated MEMS sensorsOptically 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)
Courtesy Connie Chang-Hasnain
Courtesy Connie Chang-Hasnain
Micromachining Ink Jet Nozzles
Microtechnology group, TU Berlin
(UCLA, Fan)
(Gruning)
Gene chips, proteomics arrays.
NEMS: TOWARD PHONON COUNTING: Quantum Limit of Heat Flow.
RoukesGGroupCal TechTito
From Ashcroft andMermin, SolidMermin, Solid State Physics.
Other: NSF-Funded NSEC, Center for High-Rate Nanomanufacturing (CHN): High-rate Directed Self-Assembly of
NanoelementsNanoelements
Proof of Concept Testbed
Nanotube Memory DevicePartner: NanteroNanotemplate: Partner: Nantero first to make memory devices using nanotubes
Properties: nonvolatile, high speed at <3ns lifetime (>1015 cycles)
Nanotemplate:Layer of assembled
nanostructures transferred to a wafer. Template is intended
at <3ns, lifetime (>1015 cycles), resistant to heat, cold, magnetism, vibration, and cosmic radiation.
to be used for thousands of wafers.
Switch Logic, 1996, Zavracky, Northeastern
Inverter NOR Gate
Simple Carbon Nanotube Switch
Diameter: 1.2 nmElastic Modulus: 1 TPaElectrostatic Gap: 2 nmBinding Energy to Substrate: 8.7x10-20 J/nm
Length at which adhesion = restoring force: 16 nmActuation Voltage at 16 nm = 2 VgResonant frequency at 16 nm = 25 GHzElectric Field = 109 V/m or 107 V/cm + Geom.
(F-N tunneling at > 107 V/cm)Stored Mechanical Energy (1/2 k x2 ) = 4 x 10-19 J = 2 5 eVStored Mechanical Energy (1/2 k x2 ) = 4 x 10-19 J = 2.5 eV4 x 10-19 = ½ CV2 gives C = 2 x 10-19 << electrode capacitance! Much more energy stored in local electrodes than switch.
Biological Nanomotor
