title: Grayscale gel lithography for programmed buckling of non-Euclidean hydrogel plates.
abstract: Shape programmable materials capable of morphing from a flat sheet into controlled three dimensional (3D) shapes offer promise in diverse areas including soft robotics, tunable optics, and bio-engineering. We describe a simple method of 'grayscale gel lithography' that relies on a digital micromirror array device (DMD) to control the dose of ultraviolet (UV) light, and therefore the extent of swelling of a photocrosslinkable poly(N-isopropyl acrylamide) (PNIPAm) copolymer film, with micrometer-scale spatial resolution. This approach allows for effectively smooth profiles of swelling to be prescribed, enabling the preparation of buckled 3D shapes with programmed Gaussian curvature.
authors.affiliation: Department of Polymer Science and Engineering, University of Massachusetts Amherst, Amherst 01003, Massachusetts, USA. hayward@umass.edu.
authors.forename: Jun-Hee
authors.initials: JH
authors.lastname: Na
authors.forename: Nakul P
authors.initials: NP
authors.lastname: Bende
authors.forename: Jinhye
authors.initials: J
authors.lastname: Bae
authors.forename: Christian D
authors.initials: CD
authors.lastname: Santangelo
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Hayward