A Pneumatic Optical Soft Sensor for Fingertip Force Sensing

Abstract

This paper presents the design and development of a pneumatic optical soft sensor with a potential application to fingertip force sensing. To enable safe and successful interaction with delicate objects, it is important to measure contact force. In particular, prosthetic hands require force sensing at fingertips to enable prosthetic hands to apply appropriate force on objects when performing tasks in daily life. Emerging artificial skins usually feature delicate electronics requiring special packaging to survive in an unstructured environment. In this project, we present a robust soft force sensor with a low profile and high compliance. It consists of a soft silicone base, an inflatable chamber, a hyperelastic membrane, and a photo interrupter. External force applied on the inflated membrane will cause the change of light reflection inside the chamber and thus change the signal output of the photo interrupter. The working principle of the developed sensor is modeled, and experimental studies are performed to evaluate the working performance of the sensor and calibrate the measurements.