Crystal-confined freestanding ionic liquids for reconfigurable and repairable electronics

Abstract

Liquid sensors composed of ionic liquids are rising as alternatives to solid semiconductors for flexible and self-healing electronics. However, the fluidic nature may give rise to leakage problems in cases of accidental damages. Here, we proposed a liquid sensor based on a binary ionic liquid system, in which a flowing ionic liquid [OMIm]PF6 is confined by another azobenzene-containing ionic liquid crystalline [OMIm]AzoO. Those crystal components provide sufficient pinning capillary force to immobilize fluidic components, leading to a freestanding liquid-like product without the possibility of leakage. In addition to owning ultra-high temperature sensitivity, crystal-confined ionic liquids also combine the performances of both liquid and solid so that it can be stretched, bent, self-healed, and remolded. With respect to the reconfigurable property, this particular class of ionic liquids is exploited as dynamic circuits which can be spatially reorganized or automatically repaired.

Polymer‐assisted fully recyclable flexible sensors

“…A pioneer work using ionic crystal framework to confine ionic liquids by capillary effect offered great inspirations to enable the liquid conductors to have higher storage modulus than loss modulus. 55 The ionic crystal framework is an ionic liquid with a melting point of 72 C, which is expected to possess the free-standing character of solid materials and fluidic performance of liquid materials. Thus, this system possesses intrinsic fluidic properties without external encapsulating protection and mechanical support.…”

“…However, for the encapsulating materials, the free‐standing property and the high degree of deformation are two sides of the same coin. A pioneer work using ionic crystal framework to confine ionic liquids by capillary effect offered great inspirations to enable the liquid conductors to have higher storage modulus than loss modulus 55 . The ionic crystal framework is an ionic liquid with a melting point of 72°C, which is expected to possess the free‐standing character of solid materials and fluidic performance of liquid materials.…”

Insights into Ionic Liquids: From Z-Bonds to Quasi-Liquids

“…With progress in the aforementioned aspects, researchers will obtain a new understanding of Z-bonds and quasi-liquids and new ideas for the applications of ILs. Future applications of ILs not only will be in separations, catalysis, and electrochemistry but will also extend to other cutting-edge fields (e.g., smart materials and devices, 59 DNA analysis, 194 cell membrane protein extraction, 195 and drug synthesis).…”

Visualizing thermal distribution through hydrogel confined ionic system

“…This abnormal phenomenon has been investigated for years, and the critical temperature was found adjustable ( Men et al., 2012 ; Li et al., 2019a ; Choi and Yethiraj, 2015 ), which appears to be ideally suitable for the thermal visualization. However, the mixture of ionic liquid and solvent is hardly freestanding, making it scarcely possible to attach to the surface of an object ( Matsumoto and Endo, 2008 ; Gao et al., 2019 ; Wang, 2020 ; Zhou et al., 2019 ). An encapsulating container is essentially needed to confine the mixture of IL and solvent in a specific region which goes against rapid thermal transmission and also meets the leakage problem ( Chen et al., 2018 ; Yang et al., 2018b ; Lu et al., 2019 ; Zhao et al., 2020a , 2020b ).…”