Structure-regenerated silk fibroin with boosted piezoelectricity for disposable and biodegradable oral healthcare device

Pressure sensors based on natural piezoelectric polymers, serving as green wearable electronics, have potential applications in human-machine interfaces, healthcare and biomedical engineering/technology owing to their degradability and biocompatibility. However, it is currently a big challenge to tune the piezoelectric performance of biomaterials to fabricate green, low-energy-consumed flexible pressure sensors with high mechano-electrical output performance. Here, we fabricated a green and high-output self-powered force/pressure sensor composed of an oriented silk fibroin mat and a micro-structured electrode for disposable force sensor applications in a simple and scalable way. The as-fabricated silk fibroin mat shows significantly improved piezoelectric output after fibroin macromolecular chain structure regeneration via multiple processing field control together with the micro-structured electrode design. Specifically, the sensor shows a sensitivity of 30.6 mV/N, fast response (3.4 ms), good durability, high signal linearity and power density (5.9 mW/m 2 ) comparable with other silk-based nanogenerators. Such a force/pressure sensor could be used in monitoring the biting force of the dummy dental cast for the demos of oral healthcare application. Thus, it can effectively realize force sensing without increasing the pressure on the ecological environment, showing potential application value in the fields of disposable oral medicine devices and in vivo pressure monitoring. • A silk fibroin (SF) sensor with tunable piezoelectric performance was fabricated. • SF sensors are capable of monitoring biting force for oral healthcare application. • Energy conversion efficiency of SF mats is equal to other SF-based nanogenerators. • Such a SF sensor enables the design of disposable and digestible bioelectronics.