Highly Transparent, Stretchable, and Conducting Ionoelastomers Based on Poly(ionic liquid)s

Abstract

The rapid development of soft electronics has revitalized the research of conducting elastomers. However, the design of conducting elastomers having high stretchability and good transparency still remains a considerable challenge. In this study, we develop a highly transparent, stretchable, and conducting ionoelastomer based on a poly­(ionic liquid) in which cations are fixed to a stretchable elastomeric network and counter anions are mobile. The ionoelastomer solves the dilemma of simultaneous transparency and stretchability in the design of traditional conducting elastomers, possessing good transparency (96%) with an extraordinarily high stretchability, up to a limiting strain of 1460%. Moreover, this novel material is completely nonvolatile and nonhygroscopic, endowing the ionoelastomer with highly stable thermal, environmental, electrochemical, and mechanoelectrical properties. An underwater sensor based on the ionoelastomer is developed with good performance in an aqueous environment. Also, a transparent dielectric elastomer actuator (DEA) is demonstrated using the ionoelastomer. It is believed that the ionoelastomer would pave the way to develop exceptional conducting elastomers toward next-generation soft electronics.

All-Solid-State Self-Healing Ionic Conductors Enabled by Ion–Dipole Interactions within Fluorinated Poly(Ionic Liquid) Copolymers

“…1-Hydroxycyclohexyl phenyl ketone (photoinitiator 184, 98%, Aladdin) and 2,2,3,4,4,4-hexafluorobutyl acrylate (HFBA, 96%, Shang Fluoro) were used as received. 1-(6-(Acryloyloxy)-hexyl)-3-ethylimdazolium bis­(trifluomethylsulfonyl)­imide ([EIC 6 A]­[TFSI]) was synthesized as previously described . Acetone (99%, Guangzhou Chemical) and deionized water (18.2 MΩ·cm, Millipore) were used without further purification.…”

“…1-(6-(Acryloyloxy)-hexyl)-3-ethylimdazolium bis(trifluomethylsulfonyl)imide ([EIC 6 A][TFSI]) was synthesized as previously described. 33 Acetone (99%, Guangzhou Chemical) and deionized water (18.2 MΩ•cm, Millipore) were used without further purification. Electroluminescent phosphor ZnS:Cu and ZnS:Mn microparticles were purchased from Shanghai Keyan.…”

Soft Ionics: Governing Physics and State of Technologies

“…Such performance is achieved by infusing poly(acrylic acid) (PAA) with an ionic liquid. A similar concept of using ionogels to control DEA through ionic signals was also reported by Ming et al [50]. More recently, Shi et al reported ionic signal transmission in harsh environments by synthesizing an ionogel conductor using poly(ethyl acrylate) as the underlying polymer network [51].…”

Materials development in stretchable iontronics

“…First, lithium ionic (Li + ) salt-based SICs have been investigated. 32,[110][111][112][113][114] The ionic conduction of Li + can be facilitated by hopping or chain segmental motion of the ethylene oxide chains. 115 Studies have attempted to design the polymers in two ways based on whether the ethylene oxide groups are incorporated into the side-chain or the main chain (Fig.…”

“…Ding et al reported ionic-conducting elastomers composed of copolymers of n -butyl acrylate (BA) and oligoethylene glycol methyl ether acrylates (OEGMEA), and Li + TFSI − . 110 The BA and OEGMEAs provide elastomeric properties and lower T g , thus enabling ionically conductive without liquids (Fig. 10b).…”