Advancing rehabilitation: Knittable fiber-shaped sensors for monitoring rotator cuff injury recovery

The integration of sensors into clothes offers significant convenience for monitoring the rehabilitation of patients. However, conventional flat sensors face challenges in achieving seamless integration due to their incompatibility with clothing. Here, we created a knittable fiber-shaped capacitive pressure sensor designed for long-term monitoring of shoulder movements of patients with rotator cuff injuries. This innovative sensor incorporates copper wires and silver conductive fibers as electrodes, with a polyvinylidene fluoride (PVDF) composite fiber membrane containing zeolite imidazolate framework (ZIF-8) particles as the dielectric layer. The resultant sensor can be seamlessly while non-invasively incorporated into the garment of patents due to its exceptionally flexibility. After optimizing the number of Cu wires (4) and electrospinning time of PVDF (8 min), the knittable sensor showed a sensitivity of 0.04 kPa−1 in the range of 2–8 kPa, 10 times higher than that without ZIF-8 (0.003 kPa−1). Beyond its applications in monitoring shoulder movement across various directions and degrees, this sensor has proven its ability in monitoring breath or recording weight when encompassed into a mask or a carpet, respectively. Via integrated in daily wearings, this sensor holds immense potential in the fields of rehabilitation monitoring and personal health management due to its remarkable sensitivity and flexibility.