Soft Fabric-Based Pneumatic Sensor for Bending Angles and Contact Force Detection

This paper presents the design and the development of a novel fabric-based pneumatic sensor for sensing external bending angles and compressive contact forces. This sensor system is a soft sensor system aimed at addressing issues with the use of sensors alongside soft actuators, where the material compliance is of key importance. The principle of the sensor system is based on the detection of changes in the pressure within its mechanical component, a fabric air chamber, in response to an externally applied force. A comprehensive suite of characterization tests was carried out on the sensor system to elucidate its responses to a range of bending and compressive loads. The key advantages of the sensor system are the material compliance of its fabric construction, allowing for adherence to mechanical structures, and the physical separation of the mechanical and electrical components, allowing for flexibility in the sensor's deployment. As a proof of concept, the fabric-based sensor was deployed in two distinct application domains: as a sensorized assistive glove for hand-impaired patients, and as an additional sensor for an industrial gripper. The fabric-based sensor system was successfully deployed in both cases, showing good preliminary results in providing closed-loop feedback in the assistive glove, as well as in providing contact and slippage sensing in the industrial gripper.