Graphene-decorated polyurethane nanofiber membrane flexible sensor with different fiber orientation

Abstract

Electrospun polyurethane (PU) nanofiber membranes offer desirable properties such as large strain, good resilience, light weight, good air permeability, and good adhesion to the skin; as a result, they have a unique advantage in the development of flexible sensors. To explore the application of conductive graphene (Gr)/PU nanofiber membranes in the field of strain sensing and to study the influence of the nanofiber orientation structure on the sensing performance of nanofiber sensors, electrospinning technology was adopted to prepare PU nanofiber membranes with different fiber orientations by adjusting the rotating speed of the receiving drum. Gr/PU nanofiber membranes were prepared as strain-resistance sensors, their strain-resistance sensing performance was analyzed, and the membranes were used to monitor human motion and air vibrations. The results showed that the orientation of the nanofibers in the PU nanofiber membranes could be improved by increasing the rotation speed of the receiving drum. Gr/PU nanofiber sensors have good sensing linearity, sensitivity, and stability; an increase in fiber orientation also increases sensor sensitivity, and the sensitivity factor can reach more than 200 at 50 % strain. Sensors with a low detection threshold and high detection sensitivity, which can be used for large-scale motion monitoring of human joints and small-range motion monitoring of air vibrations, have potential applications in wearable human motion health monitoring and other fields.