A 1024-element high-performance silicon tactile imager

A 32-*32-element capacitive silicon tactile imager has been developed for use in precision robotics applications where high density and high resolution are important. The silicon chip measures 1.8 cm*1.7 cm and is organized in an X-Y matrix of 1024 capacitor elements on 0.5-mm centers. The process uses two boron diffusions (deep and shallow) followed by a silicon-to-glass electrostatic bonding step and subsequent unmasked wafer dissolution. This results in a thick center plate for the sense capacitor supported by thinner beams. A data acquisition system used with the device offers over 7-bit force resolution with a maximum operating force of about 1 gm/element.<>