POS4-0371
Folding kinetics controlled soft actuators for flexible display applications
Topic
S4. Colloids, Interfaces, and Molecular Assemblies for Functional Soft Materials
When and Where
Sep 30, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Heesuk KIM
Jinhye BAE
Presenter(s)
Giyeon Han (Chung-Ang University)
Co-Author(s)
Abstract
Hydrogel-based soft actuators are highly promising for soft robotics and flexible displays due to their intrinsic softness, high strain rates, and multi-stimuli responsiveness. However, achieving precise control over their swelling and deswelling kinetics remains a challenge for designing complex, programmable actuation systems. This study demonstrates reversible and folding kinetics programmed soft actuators using a single chemical composition hydrogel—comprising thermo-responsive poly(N-isopropylacrylamide) (PNIPAM), N,N′-methylenebisacrylamide as a crosslinker, and nanoclay (NC) as a rheological modifier. The microphase-separated structures were formed by aligning the NC via extrusion-based 3D printing, and subsequently inducing its nucleation and growth through the regulation of the PNIPAM polymerization rate. NC forms intermolecular interactions within the hydrogel matrix, its dispersity directly influences water diffusivity and polymer chain mobility. As a result, a microphase-separated hydrogel exhibits fast swelling and deswelling. The folding kinetics programmed soft actuators are achieved by incorporating hydrogels with different microphase separation degrees into a hinge-based elastomer with a bilayer architecture. Specifically, soft actuators incorporating highly phase-separated hydrogels exhibited deswelling and swelling kinetics that are 1.6 and 4.4 times faster, respectively, than those of non-phase-separated ones. Finally, we achieve a sequentially foldable multi-hinge strip and a gripper from a single-composition hydrogel system are successfully realized by leveraging such different kinetics profiles.
