Abstract
Although the optical three-axis tactile sensor has unique characteristics capable of detecting three-axis components of applied force to each sensing element of the tactile sensor, it has inevitable defects such as blind spots between sensing elements and unstable contact status on the sensor-tip. In order to overcome these defects, the authors developed a tactile sensor based on human skin structure in the previous studies. However, the tactile sensor has still even a new defect, which decreases its sensitivity by means of the skin rubber. In this paper, we introduce a new fingerprint structure to increase its sensitivity. In order to obtain the best structure of fingerprint, we perform a series of FEM analysis and experiments using the fingerprint structure. As the results of numerical simulations and actual experiments, we found the best structure, in which skin-rubber thickness is 2.5 mm and fingerprint-ridge and sensing element align in-phase.
