All-Textile Piezoelectric Nanogenerator Based on 3D Knitted Fabric Electrode for Wearable Applications
Xiaoqian Wan, Yunchu Shen, Tian Luo, Mingming Xu, Honglian Cong, Chaoyu Chen, Gaoming Jiang, Haijun He
Abstract
Flexible, air permeable and elastic self-powered sensors for human motion monitoring and assisted medical rehabilitation have recently become a hot research topic. However, most current piezoelectric sensors can not account for many characteristics. Addressing this challenge, an all-textile piezoelectric sensor (ATPS) based on 3D structured knitted fabric electrodes is reported. The ATPS consists of a piezoelectric element polyvinylidene fluoride nanofiber membrane, flexible knitted fabric electrodes, and an elastic self-adhesive bandage. Based on the flexible and efficient knitting technology, the sensor has the advantages of low cost, flexibility, simple structure, and convenient large-area manufacturing. Experimental and finite element simulation results show that the knitting pattern of fabric electrodes can enhance the piezoelectric output of ATPS. The optimal ATPS has a high voltage response sensitivity of up to 0.68 V/kPa. The proposed ATPS responds to a wide range of input forces from 0.098 to 724 N in self-powered mode, verifying its feasibility as a tactile sensor for human motion detection and recognition (throat swallowing, wrist bending, elbow bending, knee bending, walking slowly, running fast) and as a pressure sensor (Morse code, digit recognition) and demonstrating its potential for motion tracking, medical rehabilitation, and human-computer interaction.