POS4-0521
Soft actuators based on conductive Poly(N-isopropylacrylamide) cryogels
Topic
S4. Colloids, Interfaces, and Molecular Assemblies for Functional Soft Materials
When and Where
Sep 29, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Hae Jung SON
Boseok KANG
Presenter(s)
Heesu Park (Chung-Ang University)
Co-Author(s)
Abstract
Stimuli-responsive hydrogels have attracted significant attention in soft robotics due to their reversible state transitions under external stimuli such as temperature, light, pH, etc. Poly(N-isopropylacrylamide) (PNIPAM), a representative thermo-responsive hydrogel, is widely studied for soft actuation due to temperature-induced reversible phase transition and adaptability to multi-stimuli responsiveness via material combination. Conventional thermal stimulation requires heating the surrounding environment, resulting in slow response kinetics, whereas photothermal actuation induces localized and non-uniform temperature distributions in bulk hydrogels. To overcome such limitations, electro-driven Joule heating has emerged as an alternative strategy for rapid, homogeneous, and volumetric actuation. Here, we utilize freezing polymerization to synthesize a macroporous PNIPAM composite cryogel. This porous structure enables rapid water transport, allowing for a fast and volumetrically operating soft actuator driven by electrical stimulation. To impart ionic conductivity without filler-induced instability and complex fabrication, the cryogel is swollen in an electrolyte solution. This allows the electrolyte to occupy the macroporous structures, where the resulting salting-out effect lowers the lower critical solution temperature (LCST) of PNIPAM. Consequently, the synergy between rapid water transport through macropores and a lowered LCST enables low-voltage, high-speed, and energy-efficient actuation. This approach provides a versatile design framework for the next generation of electro-thermal soft robots, shifting the paradigm toward highly responsive and energy-efficient untethered systems.
