A wearable strain sensor based on polyurethane nanofiber membrane with silver nanowires/polyaniline electrically conductive dual-network

With the development of aging, researchers attach great importance to wearable strain sensors due to tremendous application prospects in artificial intelligence, motion detection, health care and other fields. In this paper, we propose an uncomplicated and efficient strategy to fabricate a wearable strain sensor based on silver nanowires/polyaniline/polyurethane (AgNWs/PANI/PU) nanofiber membrane. The related physical and chemical properties of as-prepared conductive flexible membrane is characterized and measured. To ensure the durable service in practical application, the sensor is coated with polydimethylsiloxane (PDMS), and shows certain antifouling and linear electrical signal. The construction of electrically conductive dual-network demonstrated that, in the ultra-low range of strain, AgNWs has a lower resistance to response, and with the increase of strain, PANI gradually plays a bigger role in the response. The synergism of PANI and AgNWs results in high GF of the sensor (up to 59 in the range of 0-35% elongation). Comparing GF in tension and bending test, we found that the tensile strain was the major influence factor to the change of normalized resistance. Additionally, reliable fatigue resistance, signal stability of the sensor and experiments on joint and pharynx fully prove the applicability of this sensor in artificial intelligence, motion tracking, health monitoring and other fields.

Automated summary

This paper presents a simple and efficient strategy to fabricate a wearable strain sensor based on silver nanowires/polyaniline/polyurethane nanofiber membrane, with characterized physical and chemical properties. The sensor, coated with polydimethylsiloxane, shows antifouling properties and linear electrical signal, suitable for applications in artificial intelligence, motion tracking, and health monitoring. The synergism of PANI and AgNWs in the sensor construction leads to high gauge factor and excellent performance in ultra-low strain ranges.