Water responsive soft actuator and driving method thereof
AssigneePostech Research and Business Development Foundation
InventorsDong Sung Kim, Hyeon Seok Han, Andrew Choi
Life of this patent
Estimating the term…
Abstract
The invention relates to a water responsive soft actuator using water responsive hydrogel whose volume hardly changes, and a method for driving the soft actuator. The water responsive soft actuator according to the invention includes polyisopropylacrylamide, and the polyisopropylacrylamide has an N-isopropylacrylamide monomer and water in a weight ratio of 87:13 to 95:5, wherein the water responsive soft actuator is driven by water absorption of the polyisopropylacrylamide.
Claims11
A water responsive soft actuator comprising water-absorbable polyisopropylacrylamide,
- wherein the water responsive soft actuator is driven by water absorption of the polyisopropylacrylamide, and
- wherein the polyisopropylacrylamide has a structure comprising crosslinked N-isopropylacrylamide, the structure corresponding to synthesis from an aqueous solution comprising N-isopropylacrylamide monomer and water in a weight ratio of 187:13 to 95:5.
A method for driving a water responsive soft actuator, the method comprising:
- (a) crosslinking N-isopropylacrylamide to make an object of a first shape including polyisopropylacrylamide;
- (b) allowing water to be absorbed into the object of the first shape to allow the object of the first shape to be in an elastically deformable state;
- (c) applying external force to the object of the first shape in an elastically deformable state to deform the object of the first shape into an object of a second shape;
- (d) drying the object of the second shape;
- and
- (e) allowing water to be absorbed into the dried object of the second shape to allow driving in the first shape;
- wherein Step (a) above comprises:
- preparing a composition including an N-isopropylacrylamide aqueous solution, a crosslinking agent, and a photoinitiator, and filling a mold with the composition;
- and
- irradiating the composition with ultraviolet rays to cross-link the N-isoprobylacrylamide, thereby forming polyisopropylacrylamide, and
- wherein a weight ratio of N-isopropylacrylamide monomer to water of the N-isopropylacrylamide aqueous solution is 87:13 to 95:5.
Dependencies are inferred from the claim text.