A capacitive proximity sensor in dual implementation with tactile imaging capability on a single flexible platform for robot assistant applications

In this paper, we have proposed and demonstrated a dual mode proximity sensor which can detect not only proximity but also touch of an object for robot assistant applications. The sensor operates in two modes: proximity mode and tactile mode. Initially, the sensor operates in proximity mode until it touches an object. When the proximity mode detects the contact of any objects, the sensor will switch its mode into tactile sensing mode for acquiring an image from an object. We have used the same platform that we developed for the tactile sensor which was presented in the last MEMS conference [1]. In the current work, we have assessed if the existing platform is suitable for dual implementation. We have tested various designs and configurations in a simple PCB fixture in order to determine the proper electrode configuration of the proximity sensor. We found that the best detection range has been obtained from the largest electrodes with the smallest gap. This implies that the dual implementation is quite plausible in the original tactile sensor platform which has a 1 mm gap between electrodes and 22 mm in length. Finally, we have demonstrated that proximity detection up to 10 cm is possible in the dual implementation in a flexible platform with adequate electrode configuration and sensing circuitry.