A triboelectric tactile sensor with flower-shaped holes for texture recognition

Touch is one of the important ways to perceive the surrounding environment. The surface texture is an essential character of an object. Here, we propose a dual-layer shielding triboelectric tactile sensor with patterned flower-shaped holes. The object surface to be measured is able to rub against the tribo-layer through the flower-shaped holes to produce a signal output. The patterned design of the tactile sensor is evolved from the contact state of the fingertips during human finger touch. In addition, two shielding layers were designed. The inner-shielding layer is used to shield the influence of the human body potential on the output signal, in order to achieve more accurate identification. The outer-shielding layer enables the flower-shaped holes to play their structural role. The proposed tactile sensor has the advantage of a single channel, resulting in a smaller amount of data collection and processing than the multi-channel scheme. With a designed convolutional neural network model, the recognition accuracy reaches 96.03% when recognizing 7 objects with designed different surface textures and 92.58% when recognizing 5 kinds of fruits and vegetables. The tactile sensing module can be easily integrated into intelligent haptic prosthesis and play an important role in future human-machine interfaces.