Simple piezoresistive pressure sensor

Simple piezoresistive accelerometer

Simple capacitive accelerometer

• Cap wafer may be micromachined silicon, pyrex, …• Serves as over-range protection, and damping• Typically would have a bottom cap as well.

C(x)=C(x(a))

Cap wafer

Simple capacitive pressure sensorC(x)=C(x(P))

ADXL50 Accelerometer

• +-50g

• Polysilicon MEMS & BiCMOS

• 3x3mm die

• Integration of electronics!

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 re-

center capacitor plates (improved linearity).

Analog Devices Polysilicon MEMS

ADXL50 – block diagram• http://www.analog.com/en/mems-and-sensors/imems-accelerometers/products/index.html

Sense Circuit

Electrostatic Drive Circuit

Proof Mass

Digital Output

MEMS Gyroscope Chip

Rotation induces Coriolis

acceleration

J. Seeger, X. Jiang, and B. Boserhalteres

MEMS Gyroscope Chip

1m D

rive

0.01Å Sen

se

J. Seeger, X. Jiang, and B. Boser

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

Single chip six-degree-of-freedom inertial measurement unit (uIMU) designed by IMI

principals and fabricated by Sandia National Laboratories

TI Digital Micromirror Device

www.dlp.com

NEU/ADI/Radant/MAT Microswitches

SEM of NEU microswitch

Drain Source

Gate

Beam

Drain Gate Source

Beam

Drain

Gate

Source

Surface MicromachinedPost-Process Integration with CMOS20-100 V Electrostatic Actuation~100 Micron Size

Feedthrough Dielectric

Seal ring

Microbump

Landing ring

Package Substrate

MEMS

MAT Microswitch

http://www.radantmems.com/radantmems/switchoperation.html

Contact End of Switch Contact Detail

Packaged Plasma SourceTop View

Side View

Die in Hybrid Package

Fabrication

PR

Glass WaferCr/Au/TiW

Expose/Dev.TiW etch

ElectroplateGold

PR stripTiW/Au/Cr etch

Bond to 10 mm diam.glass chamberspiral coil

interdigitated capacitor

to vacuum system

SEM of Interdigitated Capacitor Structure

04/21/23

Spectrometer cross-section

Surface MicromachinedSpring System

ElectrostaticActuator Plates

04/21/23

Fabricated Microspectrometers

Intensity vs. Wavelength

0

0.2

0.4

0.6

0.8

1

1.2

450 500 550 600 650 700 750

Wavelength (nm)

Inte

ns

ity

(arb

. un

its

)

=515 nm=515 nm

FWHM = 25nmFWHM = 25nm

RP = 21RP = 21

= 575nm= 575nm

FWHM = 30nmFWHM = 30nm

RP = 20RP = 20

=625nm=625nm

FWHM = 39nmFWHM = 39nm

RP = 16RP = 16

Figure 1. Qualcomm Mirasol Display IMOD Structure Showing Light Reflecting off the Thin-film Stack and Mirror Interfering to Produce Color.

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 m length cantilevered paddle after 7 hours of B.O.E. releasing and lifted up with a

1m probe (~0.35m thick, 2m gap)

Courtesy Connie Chang-Hasnain

Courtesy Connie Chang-Hasnain

Micromachining Ink Jet Nozzles

Microtechnology group, TU Berlin

Microfluidic Chips

(UCLA, Fan)

(Gruning)

Gene chips, proteomics arrays.

NEMS: TOWARD PHONON COUNTING: Quantum Limit of Heat Flow.

RoukesGroupCal TechTito

From Ashcroft andMermin, Solid State Physics.

Other: NSF-Funded NSEC, Center for High-Rate Nanomanufacturing (CHN): High-rate Directed Self-Assembly of

Nanoelements

Nanotemplate: Layer of assembled nanostructures transferred to a wafer. Template is intended to be used for thousands of wafers.

Nanotube Memory DevicePartner: Nantero first to make memory devices using nanotubes

Properties: nonvolatile, high speed

at <3ns, lifetime (>1015 cycles), resistant to heat, cold, magnetism, vibration, and cosmic radiation.

Proof of Concept Testbed

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 VResonant 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 eV4 x 10-19 = ½ CV2 gives C = 2 x 10-19 F << electrode capacitance! Much more energy stored in local electrodes than switch.

NEMS Switch Fabrication: To be discussed.

(a) Silicon chip with 500 nm of thermally grown oxide, 20 nm of tungsten, and PMMA. (b) Electron beam lithography was used to define features in the PMMA layer. An ICP etch was used to pattern the tungsten and etch down into the oxide. (c) A Cr/Au layer was evaporated and lifted off by removing the tungsten. (d) DEP was performed to assemble a small bundle of nanotubes traversing the trench between the two side electrodes.

NEMS Switch Operation

(a) Scanning electron micrograph of a switch. Atomic force microscopy scans before (b) and after (c) switch actuation. (d) Initial (solid lines), second (dashed lines), and third (dotted lines) I-V sweeps for the device seen in (a-c). This device had a vertical gap of 24 nm and a trench width of 195 nm.

NEMS Switch Problems During Operation

NEMS Switch Electro-Mechanical Model

Carbon Nanotube for Adhesion Measurement

Biological Nanomotor