Touch
panels are deemed as a critical platform for the future of
human–-computer interaction. Recently, flexible touch panels
have attracted much attention due to their superior adhesivity and
integratability to the human body. However, hydrogel- or organogel-based
devices suffer from instability due to liquid evaporation or low-conductivity
substrates. It demands an alternative functional touch panel featuring
temperature tolerance, high conductivity, and stretchability. Here,
we introduce an eutectogel by immobilizing a novel deep eutectic solvent
(DES) within 2-hydroxyethyl acrylate (HEA) covalently cross-linked
polymer scaffolds. In this DES (ethylene carbonate(EC)–LiTFSI),
the CO group of EC is unique as an electron donor exhibiting
strong coordination interactions with Li+, promoting the
dissociation of Li+ from LiTFSI to achieve excellent conductivity.
Benefiting from their traits, eutectogel presents high conductivity,
transmittance, antifreezing, and mechanical strength. In addition,
using the surface-capacitive sensing mechanism, the eutectogel can
be designed as a 1D strip and 2D rectangular touch panel which can
achieve high-resolution touching tracks, even in a low-temperature
environment and pressure-then-recovered state. This eutectogel strategy
is envisioned to facilitate the development of next-generation intelligent
devices, especially in extreme stretching and low-temperature application
scenarios.