Self-powered flexible tactile sensors

Abstract As the age of artificial intelligence arrives, flexible sensors have been rapidly evolving in emerging applications such as human-machine interaction, smart textiles, and in vitro/in vivo healthcare monitoring. Considering the demand for green sustainable energy supply, self-powered sensing systems capable of mechanoelectrical conversion have become imperative, regardless of some limitations in commercial batteries such as periodic replacement and troublesome assembly. Current innovative research in this aspect focuses on harvesting biomechanical energy from human-related motions and then converting it into electricity. To accomplish this, piezoelectric/triboelectric nanogenerators with different power-generation mechanisms have been developed. From the perspectives of diverse material and structural design, this chapter elaborates on the recent progress of piezoelectric nanogenerators (PENGs) and triboelectric nanogenerators (TENGs) with self-powered tactile sensing capacity. Additionally, the latest fabrication of flexible magnetoelectric sensors, as another avenue for mechanoelectrical conversion, has achieved a paradigm shift of electromagnetic induction from rigid to flexible application. Finally, the chapter discusses some challenges and perspectives in three types of energy harvesters.