A metal-electrode-free, fully integrated, soft triboelectric sensor array for self-powered tactile sensing

Lingyun Wang,Qing Liu,Xinge Yu,Haoyu Wang,Yunlong Zi,Yuyan Zhu,Zhaoqian Xie,Yiming Liu

doi:10.1038/s41378-020-0154-2

Abstract

The dramatic advances in flexible/wearable electronics have garnered great attention for touch sensors for practical applications in human health monitoring and human–machine interfaces. Self-powered triboelectric tactile sensors with high sensitivity, reduced crosstalk, and simple processing routes are highly desirable. Herein, we introduce a facile and low-cost fabrication approach for a metal-electrode free, fully integrated, flexible, and self-powered triboelectric tactile sensor array with 8-by-8 sensor units. Through the height difference between the sensor units and interconnect electrodes, the crosstalk derived from the electrodes has been successfully suppressed with no additional shielding layers. The tactile sensor array shows a remarkable sensitivity of 0.063 V kPa–1 with a linear range from 5 to 50 kPa, which covers a broad range of testing objects. Furthermore, due to the advanced mechanical design, the flexible sensor array exhibits great capability of pressure sensing even under a curved state. The voltage responses from the pattern mapping by finger touching demonstrate the uniformity of the sensor array. Finally, real-time tactile sensing associated with light-emitting diode (LED) array lighting demonstrates the potential application of the sensor array in position tracking, self-powered touch screens, human–machine interfaces and many others.

Highlights

The rapid development of the advanced technology of flexible/wearable electronics has enabled a variety of applications in electronic skins and human–machine interfaces[1,2,3,4,5,6,7,8]
To address the abovementioned issues, we present a facile, low-cost process to fabricate a metal-electrode-free, fully integrated, soft triboelectric sensor array (ISTSA), which is composed of an elastomer (Ecoflex) as the electrification layer and a gel state of polyvinyl alcohol/polyethyleneimine (PVA/PEI) sealed as the sensor units and electrodes
A template with a designed pattern composed of 8-by-8 sensor units and serpentine electrode lines was obtained by threedimensional (3D) printing (Fig. S1)

Summary

Introduction

The rapid development of the advanced technology of flexible/wearable electronics has enabled a variety of applications in electronic skins and human–machine interfaces[1,2,3,4,5,6,7,8]. Tactile sensors capable of transducing physical touch to electrical signals have demonstrated their practical application in human health monitoring, security monitoring, and artificial intelligence[9,10,11,12,13,14,15] based on different transduction mechanisms, including capacitance[16,17,18], piezoresistivity[19,20,21], and piezoelectricity[22,23]. The same group developed a self-powered tactile sensor with high stretchability and transparent patterned Ag nanofiber electrodes[32]. A graphene-based self-powered touch sensor with atomically thin graphene (

Methods

Results

Conclusion