Research on composite strain and stress sensors based on piezoresistive and triboelectric effects

Abstract In view of the problems that robotic arms find it difficult to effectively identify and grasp workpieces with different textures and hardness in complex industrial environments, and the low path planning accuracy of robotic arms in practical application scenarios, this paper proposes a composite sensor based on piezoresistive effect and triboelectric effect. The composite sensor simultaneously generates piezoresistive and triboelectric signals. By comparing the output signals of the sensor, it is possible to achieve high-precision dynamic monitoring of the flexible grasping and joint movement processes of the robotic arm. The base material of the piezoresistive sensor and the negative electrode material of the triboelectric sensor are both porous MXene/PDMS structures. The piezoresistive sensor enhances its conductivity by spin-coating CNT slurry on the surface of the base material and uses PVA hydrogel as the electrode. The triboelectric sensor uses copper as the positive electrode material. Experiments show that the developed sensor has a measurement range (0.015–70 kPa) and good repeatability. The experiment verifies that the composite sensor can be applied to the high-precision detection of robotic arm’s flexible gripping and joint movements.