A 32 x 32 temperature and tactile sensing array using PI-copper films

The development of a flexible 32 x 32 temperature and tactile sensing array, which will serve as the artificial skin for robot applications, is presented in this work. Pressure conductive rubber is employed as the tactile sensing material, and discrete temperature sensor chips are employed as the temperature sensing cells. Small disks of pressure conductive rubber are bonded on predefined interdigital copper electrode pairs which are patterned on a flexible copper-polyimide substrate which is fabricated by micromachining techniques. This approach can effectively reduce the crosstalk between each tactile sensing element. The mechanical and electrical properties of tactile sensing elements are measured. Also, the corresponding scanning circuits are designed and implemented. The temperature and tactile sensing elements are heterogeneously integrated on the flexible substrate. By using the integrated 32 x 32 sensing arrays, temperature and tactile images induced by the heaters/stamps of different shapes have been successfully measured. The flexible sensor arrays are bendable down to a 4-mm radius without any degradation in functionality.