Title :
A very high density bulk micromachined capacitive tactile imager
Author :
De Souza, Richard J. ; Wise, Kensall D.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Michigan Univ., Ann Arbor, MI, USA
Abstract :
This paper reports the design and fabrication of very high density planar capacitive tactile imagers intended for eventual use in live-scan fingerprinting. Prototype 16×16-element arrays have been fabricated with both 300 dots-per-inch (dpi) and 500 dpi spatial resolution. Each pixel is formed by the intersection of metal column lines on glass and p+ silicon row electrodes that are suspended by dual angular beams. Fabrication is achieved using a simple 7-mask high-yield dissolved-wafer process. The 300 dpi and 500 dpi tactile imagers have a force sensitivity of 150 N/m and 90 N/m, respectively; this can be easily adjusted by varying the beam thicknesses
Keywords :
elemental semiconductors; fingerprint identification; image scanners; microsensors; silicon; tactile sensors; Si; Si bulk micromachined capacitive tactile imager; beam thicknesses; design; dissolved-wafer process; dual angular beams; fabrication; force sensitivity; force transducer; glass; intersection; live-scan fingerprinting; mechanical design; metal column lines; p+ Si row electrodes; scanner; spatial resolution; Capacitance; Capacitive sensors; Capacitors; Circuits; Electrodes; Fingerprint recognition; Force sensors; Glass; Pixel; Silicon;
Conference_Titel :
Solid State Sensors and Actuators, 1997. TRANSDUCERS '97 Chicago., 1997 International Conference on
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-3829-4
DOI :
10.1109/SENSOR.1997.635743
