Self-Powered and Imperceptible Electronic Tattoos Based on Silk Protein Nanofiber and Carbon Nanotubes for Human–Machine Interfaces

摘要

Triboelectric electronic skins (E-skins) can be used as primary interactive devices for human-machine interfaces (HMIs). However, devices for seamless on-skin operations must be soft and deformable, and attachable to and compatible with the skin. In this paper, a substrate-free, skin-compatible, skin-attachable, mechanically deformable, and self-powered E-tattoo sticker consisting of carbon nanotubes (CNTs) and silk nanofibers (SNFs) is presented. The E-tattoo can be imperceptibly tattooed on the skin and removed with water. When the device touches naked skin, triboelectric signals are generated. Because of the micro-to-nano hierarchical pores (with high surface-to-volume ratios), contact-induced electrification generates a power density of approximate to 6 mW m(-2) and pressure sensitivity of approximate to 0.069 kPa(-1). The power generated on the tattooed skin can activate small electronic devices. Moreover, whole-body joint movements can be monitored and tactile movements can be mapped by reading the generated electrical signals. The presented E-tattoo system can promote the development of flexible energy and sensor systems for self-powered, energy-autonomous, imperceptible E-skin devices for HMIs and artificial intelligent robotics and prostheses.