Flexible and wearable fibers for motion sensing

• Main Author: Guan, Xing
• Other Authors: Wei Lei
• Format: Thesis-Master by Coursework
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/154251
• Institution: Nanyang Technological University

In recent years, smart wearable technology has become an emerging data flow portal by integrating technologies in the information field and material field. Sensors, as the core of wearable technology devices, can convert physiological signals of the human body or external environmental signals into electrical signals, thereby providing an interface for information transmission between the human body and electronic information systems. However, traditional sensors are large in size, rigid, and highly dependent on external power sources, which reduce the flexibility, comfort, and bio-compatibility of wearable devices. Therefore, designing a self-powered flexible sensor has become one of the research hot spots. The triboelectric nanogenerator (TENG) can continuously convert the small, low-frequency mechanical energy produced by the human action into electrical energy to supply electricity for itself. It has advantages of simple preparation, high efficiency, environmental friendliness, wide material sources, and linear correlation between pressure and output voltage. So it could be used as a pressure sensor for practical applications to get rid of the shackles of traditional batteries and truly realize passive sensing. The triboelectric sensor combined with textile substrate possesses both the excellent flexibility of the textile and the self-driving performance of the triboelectric nanogenerator. It can meet the requirements of light-weight, soft, and comfortable wearable devices. In this paper, PVDF and CPE are used to prepare the cladding and core of the fiber. To achieve uniformity and toughness, thermal-drawing technique is used for the production until we get sufficient samples. According to the diameter of the fibers, they are divided into three groups for further experiment, and the encapsulation process was adopted to ensure a reliable result. To study the output behavior of the triboelectric nanogenerator operating in single-electrode(SE) mode, fibers were arranged in a cluster (1,2,4,8 strands) and weaved into a crossed structure. The output rules of this single electrode TENG were studied and the touchpoint detection function of knitted TENG was verified.