Highly Stretchable and Transparent Ionic Conductor with Novel Hydrophobicity and Extreme-Temperature Tolerance

Abstract

<jats:p>Highly stretchable and transparent ionic conducting materials have enabled new concepts of electronic devices denoted as iontronics, with a distinguishable working mechanism and performances from the conventional electronics. However, the existing ionic conducting materials can hardly bear the humidity and temperature change of our daily life, which has greatly hindered the development and real-world application of iontronics. Herein, we design an ion gel possessing unique traits of hydrophobicity, humidity insensitivity, wide working temperature range (exceeding 100°C, and the range covered our daily life temperature), high conductivity (10<jats:sup>-3</jats:sup>~10<jats:sup>-5</jats:sup> S/cm), extensive stretchability, and high transparency, which is among the best-performing ionic conductors ever developed for flexible iontronics. Several ion gel-based iontronics have been demonstrated, including large-deformation sensors, electroluminescent devices, and ionic cables, which can serve for a long time under harsh conditions. The designed material opens new potential for the real-world application progress of iontronics.</jats:p>

A Mechanically Robust and Versatile Liquid‐Free Ionic Conductive Elastomer

“…Soft machines have made the transition from conventional electronics to ionotronics, exemplified by the emergence of a variety of ionotronic devices, such as stretchable touchpads, [ 1 ] skin‐like sensors, [ 2–4 ] ionic cables, [ 5,6 ] nanogenerators, [ 7 ] soft diodes, [ 8 ] and flexible displays. [ 9 ] Unlike electronic‐based devices, which rely mostly on electrons to conduct electricity, ionotronic devices function predominantly by the motion of ions, just as what living organisms do.…”

“…[ 11,19,20 ] In recent years, ionic conductors based on ionic liquids (ILs), aka ionogels, have garnered great attention, owing to their non‐volatile nature, excellent thermal stability and ionic conductivity. [ 3,21–24 ] The common problem faced in this system is the leakage of IL when subjected to mechanical forces (e.g., squeezing). [ 25 ] Strategies such as fabricating conductive nanochannels and employing ILs that can form hydrogen bonds with polymer chains have been proposed to prevent the loss of ILs.…”

Stretchable, Phase‐Transformable Ionogels with Reversible Ionic Conductor–Insulator Transition

“…[ 22,23 ] Moreover, it is very easy to achieve good transparency with these materials, which is also desirable in the applications of optical iontronics. [ 24,25 ] Compared with hydrogel ionic conductors, PTIGs are superior due to their low volatility, and do not suffer from the well‐known evaporation problems of hydrogels. [ 26,27 ]…”

“…[22,23] Moreover, it is very easy to achieve good transparency with these materials, which is also desirable in the applications of optical iontronics. [24,25] Compared with hydrogel ionic conductors, PTIGs are superior due to their low volatility, and do not suffer from the well-known evaporation problems of hydrogels. [26,27] Herein, we report highly stretchable and transparent iontronics based on PTIGs with a sharp and reversible change in bulk ionic conductivity around ambient temperature.…”

Highly Stretchable, Conductive Polymer Electrodes with a Mixed AgPdCu and PTFE Network Interlayer for Stretchable Electronics

“…Various materials including conductive polymers, carbon nanotubes (CNT), graphene, ionic conductors, metallic nanowires have been suggested as substitutes for use in metal electrodes for stretchable electronics. [ 12–16 ] Song et al. reported on a new carbon black‐CNT hybrid filler achieved by further reacting with the CNT prepared via free radical polymerization.…”