Figure 6.

Applications of strain-based flexible sensors in smart wearable sensing: (a) a schematic diagram of flexible piezoresistive sensors adapted for human motion, including two layers of ITO electrodes, BNNS/PDMS piezoelectric active layer, and TFPS on the hand device [51]; (b) the structure of a high-performance strain-based sensor and a flexible transistor based on the piezoelectric effect, where PET is the flexible substrate and PMMA is the dielectric layer [52]; (c) the structure of a high-performance flexible piezoelectric sensor and transistor based on the piezoelectric effect, where PET is the flexible substrate and PMMA is the dielectric layer [53]; and (d) the mechanism of electrospinning BaTiO₃/PVDF composite fibers and the open circuit voltage response to the different sounds of the device vibrating from the speaker [54].