Stretchable Transparent Electrode via Wettability Self-Assembly in Mechanically Induced Self-Cracking

Abstract

Stretchable and transparent electrodes (STEs) are indispensable components in numerous emerging applications such as optoelectrical devices and wearable devices used in health monitoring, human–machine interaction, and artificial intelligence. However, STEs have limitations in conductivity, robustness, and transmittance owing to the exposure of the substrate and fatigue deformation of nanomaterials under strain. In this study, an STE consisting of conductive materials embedded in in situ self-cracking strain-spread channels by wettability self-assembly is fabricated. Finite element analysis is used to simulate the crevice growth using the representative unit cell network and strain deformation using a random network. The embedded conductive materials are partly protected by the strain-opening crevice channel, and network dissociation is avoided under stretching, showing a maximum strain of 125%, a transmittance of approximately 89.66% (excluding the substrate) with a square resistance of 9.8 Ω sq–1, and high stability in an environment with high temperature and moisture. The wettability self-assembly coating process is verified and expanded to several kinds of hydrophilic inks and hydrophobic coating materials. The fabricated STE can be employed as a strain sensor in motion sensing, vital sign and posture feedback, and mimicking bioelectronic spiderweb with spatial gravity induction.

An electrophoretic e‐paper device with stretchable, washable, and rewritable functions

“…The long‐time UV‐ozone treatment will oxidize the PDMS to grow a brittle layer SiO x and the microcracks that can be expanded under the biaxial stretching in the surface of the PDMS substrate 30 . Inspired by this, we exhibited a washable and stretchable electrophoretic e‐paper, which consists of a display layer (the mixture of PDMS and microcapsules), two electrodes obtaining by blade coating the AgNWs into the microcracks, and an encapsulation layer (Figure 1).…”

“…In previous research, Xu et al simulated the self‐cracking process and the strain distributions of the microcrack under tensile strain 30 . However, the electric field distribution of the microcrack device with the self‐cracking process has not yet been discussed.…”

“…Recently, various transparent and conductive materials have been used for flexible and transparent electrodes of optoelectronic devices, such as carbon nanotubes, graphene, conductive polymer, ionic conductors, and metal‐oxide 27–29 . From the manufacturing process to the conductive materials, our group has also investigated the self‐cracking fabrication and assembled the conductive material into the channel using hydrophilic, hydrophobic treatment, improving the maximum strain tolerance of the transparent, stretchable electrode while maintaining the conductivity 30 …”

Binary Co-Gelator Strategy: Toward Highly Deformable Ionic Conductors for Wearable Ionoskins

“…Stretchable electronics, including electronic skins (E-skins), − soft robotics, , artificial muscles, , and human motion monitoring systems, − have attracted enormous attention as next-generation wearable device platforms. Conventional stretchable systems are composed of elastomers (e.g., Ecoflex, poly­(dimethylsiloxane) (PDMS)) and electronically conducting fillers (e.g., carbon materials, , metal nanowires, , and conducting polymers − ). The fillers provide an electrical path through the connection, and the system utilizes its strain-dependent electrical properties.…”

60‐1: Distinguished Paper: An Electrophoretic E‐Paper Device with Stretchable, Washable, and Rewritable Functions

“…[27][28][29]. From the manufacturing process to the conductive materials, our group has also investigated the self-cracking fabrication and assembled the conductive material into the channel using hydrophilic, hydrophobic treatment, improving the maximum strain tolerance of the transparent, stretchable electrode while maintaining the conductivity [30].…”