Ionic diode-based self-powered ionic skins with multiple sensory capabilities. (September 2022)

• Record Type: Journal Article
• Authors: Du, Mingyu; Zhang, Delin; Fan, Wenxin; Zhao, Kai; Xia, Yanzhi; Nie, Zhihong; Sui, Kunyan
• Is Part Of: Materials today physics. Volume 26(2022)
• Publication Date: 2022-09
• Subjects: Hydrogels -- Ionic skins -- Ionic diodes -- Mechanoelectric conversion mechanism -- Multifunctionality; Materials science -- Periodicals; Physics -- Periodicals; Electronic journals; 530.41
• DOI: 10.1016/j.mtphys.2022.100744
• Languages: English
• ISSNs: 2542-5293

Abstract

Abstract: Ionic diode consisting of a pair of polycation and polyanion conductors can serve as self-powered ionic skin capable of transforming external stimuli into the potential signals through ions like human skin. The major barriers to their applications include unclear mechanoelectric conversion mechanism, limited transparency and stretchability, and singular function of pressure perception. Herein, we present a versatile strategy for constructing transparent and stretchable ionic diode-based self-powered multifunctional skins composed of a hydrogel-based ionic diode sandwiched between two ionic hydrogel electrodes. Benefiting from such sandwich structure, the self-powered skins can detect small variations in not only pressure/strain, but temperature, salinity and pH with high sensitivity and reproducibility based on thermodiffusion or salinity gradient-induced change of potential. In particular, we demonstrate for the first time that the ionic diode-based devices constitute two mechanoelectric conversion mechanisms, namely the thickness-dependent self-induced potentials of ionic diodes and varying potential losses at the diode/electrode interfaces. This work provides a route to the construction of high-performance bionic ionic sensory systems. Graphical abstract: Image 1 Highlights: The mechanoelectric conversion mechanism of ionic diode-based skins has been revealed. The diode-based self-powered ionic skins are entirely composed of ionic conductors. The self-powered ionic skins are transparent, stretchable, and multifunctional. The ionic skins can perceive pressure, temperature, salinity, and pH stimuli.