A thermo-sensitive hydrogel actuator in dry environment

Thermo-sensitive hydro gel has hydrophilic 3-dimensional structure whose volume is expanded at lower critical solution temperature (LCST) and contracted below the critical temperature. However, the usage of hydro gel is limited because it needs to contain hydro ions in 3-diemnsional structure in order to initiate the volumetric change.' Therefore; the hydro gel has been used only with a drug-delivery system and a passive valve in aqueous environments.