Additive manufacturing of wearable flexible sensors based on GN/flexible resin composite materials

Amidst the progression of scientific understanding and the growing focus on physical fitness, the significance of flexible sensors in monitoring human health and motion is increasingly recognized. This research presents the development of a high-performance flexible sensor tailored for human applications, utilizing a composite material formulated by integrating graphene (GN) with photosensitive resin. The composite material was crafted into flexible sensors through the employment of our in-house-developed 3D printing technology. The findings indicate that the GN/TPU composite sensor, with an optimal GN content of 3 wt%, achieves an electrical conductivity of 1.73 × 10^–3 \( {\text{m}}^{{ - 1}} \;\Omega ^{{ - 1}} \) ${\text{m}}^{-1}{\mathrm{\Omega }}^{-1}$ ; it exhibits a sensitivity factor of 0.82 under strain variations from 0 to 45% and a remarkable fracture elongation at 49%. Moreover, the sensors demonstrated superior durability and consistency, withstanding 500 loading cycles without degradation. The practical application of these sensors was further confirmed through their deployment on multiple regions of the human body for detection purposes.