Analysis of deflection behavior of microcantilevers embedded in elastomer for miniature tactile sensor

摘要

Tactile sensing recently becomes more important in the robotics field and many tactile sensors have been researched and developed, however, miniature and low-cost sensors have not been widely used in practical applications. For miniaturization and cost reduction, we have proposed and developed tactile sensor using microcantilevers fabricated by technologies of micro-electro-mechanical systems on the surface of a silicon chip and embedded in the elastomer with the hemispherical bump. In this study, to optimization of sensitivity of the tactile sensor, we have analyzed behavior of multiple microcantilevers in the elastomer. Deflection behavior of microcantilever models with application of force to the elastomer was calculated by the finite element analysis. From the analysis result, deflection amount and surface compressive strain of microcantilevers increases with applying force to the bump of elastomer. Furthermore, increase of deflection and compressive strain for microcantilevers arranged in external side is larger than that in internal side. On the other hand, the sensitivity of resistance of strain gauge on the microcantilever to force was measured experimentally. The sensitivity for the microcantilever arranged in external side on the chip surface is larger than that in internal side and indicates similar tendency to compressive strain. Therefore, by analyzing compressive strain corresponding to sensitivity using the finite element method, we can optimize the sensitivity of the tactile sensor.