A novel 3-axis tiny tactile sensor developed by 3-D microstructuring using punch creep forming process

摘要

This research has newly developed a high temperature punch creep forming technique combined with an impurity diffusion process for a downsizing of 3-axis piezoresistive tactile sensor made of single crystal silicon (Si) film. The punch creep forming for micron-thick Si films was able to realize a large out-of-plane deformation in a small area. This research has also estimated the creep coefficient, a, and the creep exponent, β, used in the creep constitutive equation for the Si films at 1050n^onC, by the backward analysis; where α=7.52×10n^-11nMPan^-βn·sn^-1nand β=1.67 were identified as the creep parameters, which was quite different from those of bulk Si [1, 2]. As a result, the three-dimensionally (3-D) deformed piezoresistive tiny tactile sensor with a diameter of 320 μm as its sensing area was designed by finite element analyses (FEA) using the creep parameters. Finally, we have succeeded in fabricating the tactile sensor by the punch creep forming. Here, the effect of the punch creep forming on the piezoresistivity without strain was little. Sensitivities in the horizontal and vertical directions of the tactile sensor roughly agreed with predicted values in FEA.