Amplified Performance of Charge Accumulation and Trapping Induced by Enhancing the Dielectric Constant via the Cyano Group of 3D-Structured Textile for a Triboelectric Multi-Modal Sensor.

To further improve the output performance of triboelectric devices, reducing charge attenuation and loss has become a hot research topic. Particularly, textiles have emerged as one of the promising research directions for triboelectric devices owing to their special internal structure and large specific surface area. In the present work, polyacrylonitrile fibers are fabricated with two distinct structures to provide a higher dielectric constant due to the strong polar properties brought about by higher dipole moment of the CN group. In addition, the complex and closely connected structure of the textile increases specific internal surface area. As a friction layer, the output voltage is shown to increase to 625% of the initial value (from 8 to 60 V) after the application of friction for a short time due to accumulation property. When acting as a trapping layer, the charge loss after injection is effectively prevented due to excellent charge trapping effect. After 24 h, the triboelectric output performance remains at ≈70% of the initial value (decreasing from 320 to 220 V), which is more than 20 times that of the polytetrafluoroethylene film, which decreases from 125 to 19 V. The device is realized for the advanced application of multi-modal sensors.