A slip sensor for biorobotic applications using a hot wire anemometry approach

We report on a novel slip microsensor that uses a strategy similar to the one employed in hot wire anemometry. The device includes a miniaturized probe kept at constant temperature by a dedicated control. The sensor fires a signal whenever it detects an increase in the convective heat transfer associated with the occurrence of mechanical slip. The sensor is microfabricated by patterning multi-layer electrodes on a flat glass substrate. The operating principle, fabrication procedures, and control strategy for the device are described in detail. A simple experimental setup was used to test the effectiveness of the proposed device. Tests were performed on bars of four commonly used materials with varying thermal properties. Also, the slip speed was varied and its effect on the performance of the sensor was evaluated. The results show that, with careful choice of the operational parameters, slip can be detected with a response time comparable to that of human skin receptors. The performance of the device can be further improved when used in conjunction with a separate pressure sensor and by improving the accuracy of the electrical resistance readings.