Mechanical filtering effect of elastic cover for tactile sensor

Tactile sensors are ordinarily covered with an elastic cover to protect the sensor from being damaged by shock or chemical contamination. The cover, however, greatly decreases the sensor´s spatial resolution. This effect becomes serious in the fabrication of a high-spatial-resolution sensor, even if the cover is only 0.2 mm thick, when the sensor requires a spatial resolution of less than 1 mm. This paper analyzes the low-pass spatial filtering effect of the cover, calculates the filtering gain for different types of elastic cover materials using the finite-element method, and gives preliminary experimental results