Triboelectric devices, driven by contact electrification and electrostatic induction, have drawn intensive attention worldwide, owing to their promising applications in mechanical energy harvesting from traffics, biomechanical motions, hydropower, wind and rain drops and self-powered sensors and devices. Meanwhile, the tremendous development of portable and wearable electronic devices makes an urgent requirement to integrate many unique attributes, such as flexibility, being self-powered and water-proof, into each personal device. These properties could be achieved by triboelectric devices and render devices excellent adaptivity in harsh operation environments.

To further understand of triboelectric devices and save costs of their performance optimization process, a theoret...[ Read more ]

Triboelectric devices, driven by contact electrification and electrostatic induction, have drawn intensive attention worldwide, owing to their promising applications in mechanical energy harvesting from traffics, biomechanical motions, hydropower, wind and rain drops and self-powered sensors and devices. Meanwhile, the tremendous development of portable and wearable electronic devices makes an urgent requirement to integrate many unique attributes, such as flexibility, being self-powered and water-proof, into each personal device. These properties could be achieved by triboelectric devices and render devices excellent adaptivity in harsh operation environments.

To further understand of triboelectric devices and save costs of their performance optimization process, a theoretical model with an additional shunt capacitor based on their working principle was proposed and derived mathematically. By the comparison with the experimental data, this novel theoretical model apparently fit much better than other reported models to demonstrate the existence and the important role of the shunt capacitor in real case. Then, the design parameters, including surface charge density, air gap, electrode area, PDMS thickness, electrode speed and loading resistor, were examined systematically and fairly compared in each experimental control group. Based on above comparisons, the design guideline for each parameter was appropriate proposed.

As a self-powered sensing application of triboelectric devices, we report an integrated triboelectric tactile sensor array with flexible, transparent, self-powered and water-proof features. Each tactile sensor is a surface nano/microtexture enhanced triboelectric nanogenerator. The sensor array can serve as a touch panel for electronic devices. Owing to a unique design of a built-in triboelectric contact pair and an electrical shielding layer, an individual pixel of the fabricated tactile sensor array can generate an open circuit voltage up to 1.613 V and a shorted circuit current density of 47.308 mA/m² under 612.5 kPa. It has been verified that the tactile sensors can produce stable voltage signals regardless of the materials of the touching objects and the sensors can work stably both in ambient and aqueous environments. To examine the touch panel function of a sensor array, a matrix of 10 × 10 individually addressable 4 mm × 4 mm triboelectric sensors have been integrated into a thin, transparent and flexible film. And the 2-D touch mapping has been successfully demonstrated. The unique triboelectric tactile sensor array reported here is robust and highly versatile, it may find broad applications in display, wearable electronics, and artificial skins, internet of things (IoT), etc.