title: Self-folding of three-dimensional hydrogel microstructures.
abstract: This letter describes the fabrication of three-dimensional particulate-like hydrogel microstructures using a combination of soft lithography and volume expansion induced self-folding. Bilayer structures are produced by solvent casting and photocuring of liquid resins. They curl into three-dimensional (3D) structures upon contacting with water due to differential swelling of the two layers. The curvature can be controlled by adjusting the polymer composition of the primary swelling layer. A simple semiempirical mathematical model is used to predict this self-folding behavior. By designing the two-dimensional (2D) shapes of the bilayers, this technique can lead to complicated 3D microstructures.
authors.affiliation: Biomedical Engineering Center and Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Jingjiao
authors.initials: J
authors.lastname: Guan
authors.forename: Hongyan
authors.initials: H
authors.lastname: He
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Hansford
authors.forename: L James
authors.initials: LJ
authors.lastname: Lee