Stretchable Triboelectric Nanogenerators for Energy Harvesting and Motion Monitoring

Abstract

Motion monitoring by flexible strain or pressure sensors have been under spotlight in the field of wearable electronics. Based on triboelectric effect, generated energy from body contact and compression during daily movement can be used for both reflecting motion status and energy recollection. Here, we report a stretchable pressure sensor based on triboelectric effect and dots-distributed metallic electrodes, adopting contact-separation mode. The dots-distributed electrode based triboelectric nanogenerator (D-TENG) could be easily integrated with body and cloth, such as on the skin and under foot, to sense a broad range of activity related strain information. The D-TENGs enable accurate detecting a broad range pressure from ~5 kPa to ~50 kPa with open circuit voltage variation from several volts to tens of volts, and thus allow monitoring body daily actives such as joints' bending, walking and running. These devices maintain stable and high-level signal outputs even after thousands cycles of measurement, proving the good stability. Simultaneously, the mechanical energy produced by our body motions could also be recollected by the D-TENG sensor for energy harvesting. Under a constant tapping by finger (39.59 kPa), the induced voltage is sufficient to light up 15 LEDs. The stretchable D-TENG sensor indicates its great potential in motion monitoring and mechanical energy harvesting.