Investigation and Implementation of Elastomer Filament Strain Sensors for Monitoring of Hand Gestures

The recognition of human gestures in real-time using body attached sensors has brought attention in recent years due to the manifold potential applications. The implemented sensors must be flexible, easy to adapt to bodily parts, highly sensitive and biocompatible. In this work a novel strain sensor is investigated which is based on a conductive thermoplastic polyurethane (CTPU) blended with a biocompatible soft thermoplastic polyurethane polymer (STPU). The sensor shows a high capability to transfer the mechanical deformation into an electrical response with high sensitivity. An investigation of the sensing properties using different mixture percentage of STPU/CTPU starting from 10/0 to 0/10 is carried out. The sensing behavior is characterized based on several mechanical and electrical properties e.g. stretchability, sensitivity, linearity, repeatability and hysteresis. The composition STPU/CTPU 7/3 showed a better performance compared to other studied compositions, where the elastic zone estimated was ∼13 (linearity = 0.98 within elastic zone) and 39 of sensitivity. The mentioned sensor's response demonstrates high repeatability and low hysteresis effect. Finally, the selected sensor composition was attached to a glove where the movement of a finger was successfully tracked.