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 wireanemometry. The device includes a miniaturized probe kept at constant temperature by a dedicatedcontrol. The sensor fires a signal whenever it detects an increase in the convective heat transfer associatedwith the occurrence of mechanical slip. The sensor is microfabricated by patterning multi-layer electrodeson a flat glass substrate. The operating principle, fabrication procedures, and control strategy for the deviceare described in detail. A simple experimental setup was used to test the effectiveness of the proposeddevice. 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 resultsshow that, with careful choice of the operational parameters, slip can be detected with a response timecomparable to that of human skin receptors. The performance of the device can be further improvedwhen used in conjunction with a separate pressure sensor and by improving the accuracy of the electricalresistance readings.