Bilayered polyurethane/dipole-dipole and H-bonding interaction reinforced hydrogels as thermo-responsive soft manipulators.

Dipole-dipole and hydrogen-bonding interaction reinforced (DHIR) hydrogels that demonstrate both excellent thermo-responsive volume change and high mechanical strength have been developed. Their thermo-responsive volume change originates from the balance between the temperature-sensitive reversible dipole-dipole and H-bonding interaction and an embedded super-hydrophilic component. By integrating these thermal responsive DHIR hydrogels with non-swelling polyurethane (PU) hydrogels, bilayered (DHIR-PU) thermomorphic actuators capable of shape transformation have been fabricated. The hybrid DHIR-PU hydrogels have a wide temperature window allowing dual-responsive actuations to be achieved. The new hydrogel-based actuators are highly attractive materials for a range of transformative applications in soft robotics, medical devices and advanced manufacturing.