Ultra-Flexible and Durable Textile Capacitors with Piezoelectric PVDF Dielectrics for Wearables

We present on the design and use of wearable capacitive patches with piezoelectric dielectrics for tracking motion, impact, posture, acoustic feedback and general biomedical health. The capacitive elements are based on ultra-flexible and durable textile electrodes and silicone dielectrics augmented with polyvinylidene fluoride - trifluoroethylene (PVDF-TrFE) fillers up to 30% w/v ratio. The resulting patches, deployed on appropriate locations and geometries, can capture critical information on the type, strength and duration between specific episodes of movements in the limbs as well as impact and acoustic response from the torso. This is possible due to the piezoelectric response ($d _{33} =24 \pm 1$ pC/N) induced by the PVDF-TrFE/Silicone composite dielectric layer. Moreover, the periphery of the patch allows for additional compact commercial sensors to be integrated along with a bluetooth-capable micro-controller platform. Consequently, the proposed piezoelectric capacitive patches with integrated arrays of sensors are ideally suited to pursue compact, cost-effective, power-efficient solutions in the emerging era of sensor fusion for complex performance monitoring, realistic worker training and for high-risk patients.