Institute For Micromachine And Microfabrication Research

1. SUB-NANOGRAM MASS MEASUREMENT IN LIQUID

A new micromachined mass measurement tool can now detect changes of less than 0.5 nanogram (half a billionth of a gram) in liquid media. This is much smaller than the mass of many living cells and because it works under water or in solution, it means that the changing mass of a single living cell can be observed during natural life processes. The new device is based on a 180 mm long micromachined cantilever arm that resonates. On-chip circuitry detects subtle changes in resonance frequency and hence infers the mass of anything on the 'balance' arm. Many biomedical and microbiological applications for the device exist.

Design: J. Chen, S. Prescesky, R. Turner, A. Parameswaran

Fabrication: J. Chen, S. Prescesky

2. PRESSURE TIME RECORDER

With no moving parts, requiring no power and readable by the naked eye this device is useful to doctors who need to know the product of pressure and time (PT) in medical applications. Some pneumatically powered medical instruments need to be serviced after operating at pressure for a certain length of time. Also, the device is valuable in the field in the Third world for PT sensitive procedures such as changing tourniquets, etc. It is currently being tested in the operating rooms of the Vancouver General Hospital.

Design: P. Gadgil

Fabrication: P. Gadgil, K. Chung

3. THERMAL PERISTALTIC PUMP (FRONT AND BACK VIEWS)

A micropump without valves that moves microlitre volumes of fluids by thermal expansion or phase change. Ten sequentially powered tiny heating elements under a micromachined channel drive the fluid from one end to the other. This pump was designed under a joint collaboration agreement with the Mechanical Engineering Lab in Tsukuba, Japan.

Design: M. Mehta, H. Takagi, A. Parameswaran

Fabrication: M. Mehta, H. Takagi

4. DNA AMPLIFICATION CHAMBER

Recent developments with the Polymerase Chain Reaction (PCR) have allowed genetics researchers to replicate a specific strand of DNA in quantity for identification and other experimental purposes. This tiny PCR reaction chamber reduces the time required for the PCR reaction. In normal practice this reaction must be repeated many times to amplify one sample. The process is all automated, but due to necessary heating and cooling times, a typical reaction cycle takes about 10 minutes. The new micromachined reaction vessel holds about 40 microlitres of DNA solution and cycles in only 6 minutes. The reaction cavity is located behind the resistor in the centre of the chip on the left. The project is a collaboration with Dr. Robin Turner at the UBC Biotechnology Laboratory.

Design: S. Wu, A. Parameswaran, R. Turner

Fabrication: S. Wu

5. MICROMACHINED DNA PURIFICATION UNITS

These two devices purify DNA by pumping a DNA-containing solution through micromachined columns. DNA is precipitated on specially prepared column walls. Subsequent flushing yields more concentrated and purified DNA. This first generation device is shown on a 4" silicon wafer. A miniaturized version is shown at upper right as a semi-packaged unit with glass inlet and outlet ports.

Design: C. Haynes, A. Parameswaran, R. Turner

Fabrication: G. Waynes, A. Parameswaran

6. TACTILE SENSOR FOR ENDOSCOPIC SURGERY

This preliminary prototype is mounted on a standard chip package for testing but ultimately the micromachined pressure sensor assembly would be mounted on the gripping ends of an endoscopic surgery tool. Such tools are in common use for less invasive surgery on gallstones, hernias and other procedures. A problem is the lack of tactile feedback these tools provide the surgeon. The new tactile tool will solve this by giving different feedback signals depending on what the tool is grasping--fat, muscle, tumor, etc.

Design: M. Mehta, A. Parameswaran, S. Payandeh

Fabrication: M. Mehta

7. APPLIED PRESSURE SENSOR FOR CLINICAL USE

This prototype micromachined silicon pressure sensor package can be used to measure exact pressure under a cuff or a tourniquet or in specialized surgical procedures. The long curving tube is a vent, part of the sensor package, which enables high dynamic range operation and back pressurization for equalization and hysteresis compensation.

Design: J. Melin, A. Parameswaran, J. McEwen

Fabrication: J. Melin

8. PROSTATE CANCER DETECTOR

This prototype packaged device combines pressure and flow sensors on a single substrate to allow dynamic measurement of voiding urine to identify early symptoms of prostate trouble. Urine passes through the plastic tube and sensors are mounted on the chip carrier. The two dies sitting on the left side of the chip carrier are the flow (L) and pressure (R) sensors which are combined in the sensor housing on the chip carrier beneath the plastic tubing.

Design: V. Gupta, A. Parameswaran, J. McEwen

Fabrication: V. Gupta, M. Paranjape

9. CMOS MICROMACHINED FLOW SENSOR

Six polysilicon resistors fabricated in the centre of this suspended platform are at the heart of this sensor. While one of the resistors heats the platform, on board circuitry senses the change in resistance in the other five due to the cooling effect of gas flow across the surface. The microscopic device costs pennies to produce and can be used in air conditioning systems for monitoring gas flow in process control systems.

Design: A. Parameswaran

Fabrication: Northern Telecom Electronics (CMC)

10. DYNAMIC THERMAL SCENE SIMULATOR

An example of integrating micromachining and circuitry on the same substrate: this four element (2x2) CMOS micromachined device can produce two dimensional infra-red images for calibration and testing of navigational guidance systems. The technology has been applied in commercial products by Optical ETC Inc. of Huntsville, Alabama.

Design: R. Chung, A. Parameswaran, M. Syrzycki

Fabrication: Northern Telecom Electronics (CMC)

11. INCANDESCENT PIXEL

An example of a CMOS micromachined polysilicon filament (144 x 102µm) producing an incandescent glow. The device consumes 45 milliwatts to produce a filament temperature of 1200 °ree;K.

Design: A. Parameswaran

Fabrication: Northern Telecom Electronics (CMC)

Characterization: J. Geist and D. Blackburn, NIST, Gaithersburg, Maryland.

12. MULTIPROJECT WAFER (FRONT AND BACK)

This wafer is an example of the micromachine work done at the Institute of Micromachine and Microfabrication at Simon Fraser University. The 4" wafer sports an assortment of pressure sensors, flow sensors, and DNA processing chambers.

Design: A. Parameswaran, M. Paranjape

Fabrication: M. Paranjape