AN INKJET PRINTED PIEZORESISTIVE BACK-TO-BACK GRAPHENE TACTILE SENSOR FOR ENDOSURGICAL PALPATION APPLICATIONS

Abstract

The paper presents a tactile sensor design mimicking human finger touch to differentiate tissue hardness for endosurgical palpation applications. The sensor comprises two inkjet-printed piezoresistive graphene-based sensing elements linked back-to-back for force and displacement detection, respectively. Experimental results indicate the sensor registers 2.1 and 5.3 mN force feedback from the fat and muscle tissues of pig, respectively, when pressed to the tissues with the same 100 mu m displacement. This difference of similar to 2.5 times in force feedback provides a compelling method by which doctors can more intuitively perceive hardness and tissue differences during endosurgery in comparison with the prior arts.