Simple piezoresistive pressure sensor Simple piezoresistive accelerometer Simple

Simple piezoresistive pressure sensor

Simple piezoresistive accelerometer

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

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

ADXL 50 Accelerometer • +-50 g • Polysilicon MEMS & Bi. CMOS • 3 x 3 mm die • Integration of electronics!

ADXL 50 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).

Analog Devices Polysilicon MEMS

ADXL 50 – block diagram • http: //www. analog. com/en/mems-and-sensors/imems-accelerometers/products/index. html

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

MEMS Gyroscope Chip 1 m e iv Dr J. Seeger, X. Jiang, and B. Boser m Å 1 0. 0 e s n Se

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

Single chip six-degree-of-freedom inertial measurement unit (u. IMU) designed by IMI principals and fabricated by Sandia National Laboratories

TI Digital Micromirror Device

www. dlp. com

NEU/ADI/Radant/MAT Microswitches http: //www. radantmems. com/radantmems/switchoperation. html Surface Micromachined Post-Process Integration with CMOS 20 -100 V Electrostatic Actuation ~100 Micron Size Gate Drain Beam Source Beam Drain Gate Source Gate SEM of NEU microswitch Landing ring Drain Source MEMS Seal ring Microbump Feedthrough Dielectric Package Substrate MAT Microswitch

Contact End of Switch Contact Detail

Packaged Plasma Source Top View Die in Hybrid Package Side View

Fabrication SEM of Interdigitated Capacitor Structure

Spectrometer cross-section Surface Micromachined Spring System Electrostatic Actuator Plates 11/29/2020

Fabricated Microspectrometers 11/29/2020

Intensity vs. Wavelength l =515 nm l = 575 nm FWHM = 25 nm FWHM = 30 nm l =625 nm RP = 21 RP = 20 FWHM = 39 nm RP = 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 Sensors Uniform cantilever beam Cantilevered paddle Foster Miller - Diaphragm Cantilevered supported diaphragm

Optically interrogated MEMS sensors 55 mm length cantilevered paddle after 7 hours of B. O. E. releasing and lifted up with a 1 mm probe (~0. 35 mm thick, 2 mm 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. Roukes Group Cal Tech Tito

From Ashcroft and Mermin, Solid State Physics.

Other: NSF-Funded NSEC, Center for High-Rate Nanomanufacturing (CHN): High-rate Directed Self-Assembly of Nanoelements Proof of Concept Testbed Nanotube Memory Device Nanotemplate: Ø Layer of assembled nanostructures transferred to a wafer. Template is intended to be used for thousands of wafers. Partner: Nantero first to make memory devices using nanotubes Properties: nonvolatile, high speed at <3 ns, lifetime (>1015 cycles), resistant to heat, cold, magnetism, vibration, and cosmic radiation.

Switch Logic, 1996, Zavracky, Northeastern Inverter NOR Gate

Simple Carbon Nanotube Switch Diameter: 1. 2 nm Elastic Modulus: 1 TPa Electrostatic Gap: 2 nm Binding Energy to Substrate: 8. 7 x 10 -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 = 109 V/m or 107 V/cm + Geom. (F-N tunneling at > 107 V/cm) Stored Mechanical Energy (1/2 k x 2 ) = 4 x 10 -19 J = 2. 5 e. V 4 x 10 -19 = ½ CV 2 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