Highly sensitive and wide-range flexible strain sensors based on dual conductive networks and multilayer bending structures for multi-deformation detection

Abstract

The challenge in the development of flexible strain sensors is achieving high sensitivity and wide detection range, which is important for multi-deformation detection. In this study, a strain sensor based on dual conductive networks and multilayer bending structures was studied for multi-deformation detection. The dual-layer conductive network was obtained by uniformly depositing CNTs and graphene on the surface of the flexible substrate through ultrasonic vibration. The multilayer bending structures were fabricated by a sacrificial mould printed by a fused deposition 3D printer. The result shows that the flexible strain sensor exhibits high sensitivity (GF = 1021.93, 200 % ≤ ε ≤ 240 %), broad detection range (strain up to 240 %), low detection limit (0.3 %) and rapid response time (360 ms). Furthermore, the sensor can be used for multi-deformation detection, such as stretching, twisting and bending. These properties enable the flexible strain sensor to provide real-time monitoring larger movements of human behaviour, such as finger bending and leg bending. It also can monitor small movements, such as the recognition of the sound at the throat, and the word written by the pen tip. In addition, a sensory glove based on five sensors were designed to realize the recognition of different gestures and different size objects.