Flexible and tactile sensor based on a photosensitive polymer

This paper presents a novel design of tactile sensing arrays with integrated strain gauges for the measurement of contact force. Surface stress or strain changes on the sensor area due to applied force are measured by the encapsulated Au gauges. The fabricated tactile sensors are highly flexible and durable so that they can conform to more complex surfaces without damaging the skin structure and the metal interconnects on the sensing array. The experimental results show the output characteristics are linear with contact force from 0 to 700 gf and a sensitivity of 3%/100 gf within the full scale range of 700 gf. The effect of electrode structure and position on the enhancement of sensitivity are also numerically simulated by a finite element method and verified experimentally. The measured tactile sensors are robust enough for direct contact with human and contaminants without undue care. (C) 2009 Elsevier B.V. All rights reserved.