Design concept of high-performance flexible tactile sensors with a robust structure

We introduce a new concept of a flexible tactile sensor array capable of sensing contact force and position with high performance and high spatial resolution. The proposed sensor array consists of a sub-millimetre-size bar-shaped semi-conductor strain gage array attached to a thin and flexible printed circuit board covered by stretchable elastomeric material on both sides. This design incorporates the benefits of both materials, the semiconductors' high performance and the polymer's mechanical flexibility and robustness, while overcoming the drawbacks of those two materials. For this paper, we have tested the feasibility of using this concept to develop high performance flexible tactile sensors; we fabricated a 5 x 5 sensor array of tactile sensors with commercial semiconductor strain gages. Each sensor element shows the good performances in terms of resolution better than 0.4 kPa, repeatability less than 1%, hysteresis less than 3%, zero return error less than 1%, and no observable drift over time.