Transparent, mechanically robust, and ultrastable ionogels enabled by hydrogen bonding between elastomers and ionic liquids
Nonvolatile ionogels have recently emerged as promising soft electrolyte materials for use in flexible electronics. However, it remains challenging to fabricate highly robust and stable transparent ionogels. Here, high-performance ionogels with excellent transparency, mechanical robustness, and ultrastability are designed by virtue of hydrogen bonding between poly(ethyl acrylate)-based elastomers and room-temperature ionic liquids (ILs). Through rationally tuning chemical structures of ILs and thus achieving good compatibility of ILs with elastomer, the transparent hydrophobic ionogels exhibit super-strong mechanical properties (favorable elasticity of 15 ~ 484 kPa, ultrahigh stretchability of more than 5000%, and record-high fracture toughness of up to 4.7 kJ m-2) and high stabilities (high thermal stability, high voltage stability, air stability, humidity resistance, strong self-adhesion, and non-corrosive stability). In particular, it is demonstrated that a skin-like sensor fabricated by the ionogel directly not only exhibits outstanding durability (10000 cycles at 100% strain), but also is capable of operation under harsh environmental conditions, including high vacuum, high/low temperature, and high humidity. It is believed that this work provides a new prospect for sophisticated wearable optoelectronic devices.