A membrane type Si-MEMS tactile imager with fingerprint structure for realization of slip sensing capability

This paper reports a newly developed Si-MEMS integrated tactile imager that can detect tri-axial input force and `slip' on the surface of the sensor in high spatial resolution (several hundreds micron). Tactile imaging is performed by a large area silicon membrane which is integrating sensor pixel array including strain gauge circuits. The new imager device presented in this paper has fingerprint-like patterns formed by Deep-RIE on the silicon sensor diaphragm. The patterns generate a rotational motion for horizontal axis input force, and it is similar with the role of human's fingerprints. Basic principle of the tactile imager was examined with FEM analysis for multi-axis input forces and the slip sensing ability. In addition, tri-axial load was successfully detected in each pixel by the new membrane sensor structure with low cross-axis sensitivities.