Some examples of fabricated prototypes include:
Devices 44K image for this project have been micromachined in the Nanofabrication Technology Laboratory and are assembled using anodic bonding.
(2) Biomedical MEMS
An optical flow cell 22 K byte image is shown in the photomicrograph. This optical flow dell device was demonstrated at the request of an instrument maker to be used in the inspection of biological fluids. Biological fluids, diluted with a solvent, are injected into the narrow end of the flow channel and exits at the wide end. A microscope with a CCD camera images the fluids in the transparent area near the wide exit port.
Automotive Projects
(1) Anemometer
This device 19K byte image was developed to measure airflow in an automobile engine. The device was tested over a range of flow ranges and operating temperatures.
The anemometer was fabricated with bulk micromachining on a low stress silicon nitride membrane. Two thin film devices were built on the membrane: one for the flow measurement and the second for temperature measurement (for temperature compensation of the sensor). The device was fabricated in the Nanofabrication Technology Laboratory.
(2)Binary Concentration Mass Flow Sensor
This novel device 38 K byte image has been demonstrated for automotive applications.
It was designed to measure the concentration of the principal two
components in a flowing gas mixture.
The device has been fabricated in two versions,
one with surface micromachining and a second with bulk micromachining. The device operates by heating the gas using a heater strip on the chip and sensing the temperature of the downstram gas with several sequential thin film sensors. Gas components can be determined by computing the gas conductivity from the sequential temperature measurements. This technique is expected to be useful for measuring the composition of natural gas for alternate fuel vehicles (and allow optimum combustion) or alternately the fuel/air ratio for stoichometric combustion. Breadboard electronics was constructed for computation and closed-loop control.
Semiconductor Projects
(1)Low Cost Ridge Waveguide Laser (8K)
(2)Chemical Sensor (49K)
(3)Semiconductor Resistivity Meter
(4)Microsprings
The design and demonstration of microsprings was sponsored by a
Costa Mesa company.
Devices 57K byte image were fabricated in the Nanofabrication Technology Laboratory.
The image shows an array of test devices with different spring designs.
The length of these springs is approximately 100 microns.
The interest of the sponsor is the development of a new class of
microactuators and sensors that can be used with
micro-optics applications.
This project was initiated as a SBIR project.
Microsprings have been fabricated using both surface and bulk micromachining.
(5) Properties of Thin Integrated Circuits There is considerable interest in very thin integrated circuits for smart cards, smart shipping labels, and wearable computers. The usual integrated circuits are 500 to 1000 micrometers in thickness. We are investigating the properties of semiconductor and MEMS devices with substrate thicknesses down to 10 micrometers or less. Interesting phenomena occurring at these smaller thickness include threshold shifts due to charge on the back of the wafer, changing bandgap with chip flexing and piezoresistive effects with chip flexing. These thin chips are very flexible but also brittle. A tester has been assembled to examine the mechanical properties of thinned die. The photomicrograph 228K byte image shows a fracture that begins along a polishing groove on the back of the wafer. The fracture quickly transitions to the lower fracture strength crystal axes.
Combustion Projects
Links to some Engineering Laboratories:
The UCI Technology Outreach Program
provides support to businesses and entrepreneurs including product prototyping, education courses, measurement
services, and analysis.
Email comments to top@uci.edu