Conductive hydrogels are a class of stretchable conductive materials that are important for various applications. However, water-based conductive hydrogels inevitably lose elasticity and conductivity at subzero temperatures, which severely limits their applications at low temperatures. Herein we report anti-freezing conductive organohydrogels by using an H O/ethylene glycol binary solvent as dispersion medium. Owing to the freezing tolerance of the binary solvent, our organohydrogels exhibit stable flexibility and strain-sensitivity in the temperature range from -55.0 to 44.6 °C. Meanwhile, the solvent molecules could form hydrogen bonds with polyvinyl alcohol (PVA) chains and induce the crystallization of PVA, greatly improving the mechanical strength of the organohydrogels. Furthermore, the non-covalent crosslinks endow the conductive organohydrogels with intriguing remoldability and self-healing capability, which are important for practical applications.

Gel electrolytes are attracting growing interest in the field of flexible solid supercapacitors. So far, hydrogel electrolytes have been widely investigated, and high performance flexible supercapacitors based on these electrolytes have been realized. However, conventional hydrogel electrolytes contain massive solvent water, inevitably freeze and restrict ion transport at subzero temperatures, which fundamentally limits the utilization of supercapacitors in extreme low temperatures. A new organohydrogel electrolyte that successfully brings the advantages of outstanding flexibility and ionic conductivity at low temperatures by using H2O/ethylene glycol as a dispersion medium is reported here. When applying the antifreezing organohydrogel electrolyte, the flexible solid supercapacitor with carbon nanotube paper electrodes (≈0.5 × 2.2 cm2) exhibits stable electrochemical performance (70.6% capacitance retained at −40 °C) and excellent cycling stability (only 11.7% capacitance decay over 5000 charge/discharge cycles at −20 °C.) at low temperatures, representing the excellent low temperature tolerance. Meanwhile, the supercapacitor devices offer remarkable flexible performance under consecutive bending conditions. It is anticipated that the low temperature tolerant organohydrogel electrolyte may be a promising gel electrolyte for the next generation of flexible solid supercapacitors for using at low temperature environments.

Flexible conductive materials have gained considerable research interest in recent years because of their potential applications in flexible energy storage devices, sensors, touch panels, electronic skins, etc. With excellent flexibility, outstanding electric properties and tunable mechanical properties, conductive hydrogels as conductive materials offer plentiful insights and opportunities for flexible electronic devices. Numerous synthetic strategies have been developed to obtain various conductive hydrogels, and high-performance flexible electronic devices based on these conductive hydrogels have been realized. This review provides a comprehensive overview of conductive-hydrogel-based flexible electronics, ranging from conductive hydrogels synthesis to several important flexible devices applications, including touch panels, sensors and energy storage. Finally, we provide new future research directions and perspectives for conductive-hydrogel-based flexible and portable electronic devices.

Conductive hydrogels are a class of stretchable conductive materials that are important for various applications. However, water‐based conductive hydrogels inevitably lose elasticity and conductivity at subzero temperatures, which severely limits their applications at low temperatures. Herein we report anti‐freezing conductive organohydrogels by using an H2O/ethylene glycol binary solvent as dispersion medium. Owing to the freezing tolerance of the binary solvent, our organohydrogels exhibit stable flexibility and strain‐sensitivity in the temperature range from −55.0 to 44.6 °C. Meanwhile, the solvent molecules could form hydrogen bonds with polyvinyl alcohol (PVA) chains and induce the crystallization of PVA, greatly improving the mechanical strength of the organohydrogels. Furthermore, the non‐covalent crosslinks endow the conductive organohydrogels with intriguing remoldability and self‐healing capability, which are important for practical applications.

We report a simple, additive-free method to fabricate asymmetric magnetic tubular microactuators for high-speed liquid transport.