An integrated flexible temperature and tactile sensing array using PI-copper films

This paper presents the design, fabrication and measurement of a flexible 8 × 8 temperature and tactile sensing array which will be used as the artificial skin for robot applications. The temperature and tactile sensing elements are heterogeneously integrated on a flexible copper-PI film using micromachining techniques. The tactile sensing elements are formed by dispensing conductive polymer on the pre-defined interdigital copper electrodes. This novel fabrication method can effectively reduce the crosstalk between each sensing element. The strategy and the verification for reducing crosstalk currents are described. The mechanical and electrical properties of tactile sensing elements are measured. Also, discrete temperature sensor chips are employed as the temperature-sensing cells. Scanning circuits are implemented. Finally, measured temperature and tactile images have been successfully obtained by using the integrated 8 × 8 sensing arrays. The flexible sensor arrays are bendable down to a 4-mm radius without any degradation in functionality.