Piezoelectric-enhanced triboelectric nanogenerator fabric for biomechanical energy harvesting

Flexible and wearable technology, a large trend in recent electronic technology revolution, proposes an urgent demand for the similarly flexible and wearable power supply. Hence a fully flexible and stretchable piezoelectric-enhanced triboelectric nanogenerator fabric (P-TNGF) possessing high output performance, good air permeability and excellent reliability is proposed in this work for human-body movement energy exploiting. Three consecutive energy conversion processes consisting of two triboelectrification processes and one piezoelectric electrification process exist at three different stages of a work period of P-TNGF, which contributes to harvest ambient energy maximally. By the optimization design of uninterrupted energy harvesting in overall process, a maximum open-circuit voltage and short-circuit current of P-TNGF can reach 600 V and 17 mu A, respectively, and a maximum output power of 1.11 W/m(2) is obtained experimentally under 20M Omega load. Moreover, the operating capability of P-TNGF in various conditions, such as different stimulation frequency and external contact materials is investigated experimentally, showing excellent reliability and availability. Prepared samples are attached to different human-body parts, such as foot and joints, to demonstrate its wearability and biomechanical energy harvesting capability. Processed by rectification circuit, alternating current generated from P-TNGF are charged into several capacitors with various capacitances, which can be utilized to drive commercial electronic devices. The proposed P-TNGF has great significance for the further development of flexible and wearable technology.