Word high gauge factor flexible capacitive strain sensor based on auxetic structure

Capacitive flexible stretch sensors, compared to resistive ones, offer better linearity and are thus more promising for human motion detection applications. Current capacitive sensors, however, face challenges in effectively enhancing their Gauge Factor (GF), limiting their sensitivity. This paper presents a capacitive stretch sensor utilizing a negative Poissons ratio structure made of high Shore hardness silicone as the framework and low Shore hardness silicone as the dielectric layer. Liquid metal composite material is used for the electrodes. Finite element simulation validated the sensors stretching effect. The sensor achieved a sensitivity of 2 pf/mm and a GF value of 2.19. Its efficacy is demonstrated through the measurement of finger joint movements, indicating broad application potential in human motion detection.