Invited Talk: Patterned Sheets and Multilayers of Photo-Crosslinkable Polymers

Our group is studying the use of photo-crosslinkable copolymers containing pendent benzophenone units as a platform for the fabrication of actuating micro-scale devices and sensors. We have studied the design considerations, in terms of  copolymer chemistry, necessary to obtain efficient UV crosslinking through this route, and found a sensitive dependence on how hydrogens susceptible to radical abstraction by triplet-state benzophenone are located on the polymer chain. With this knowledge, it is straightforward to fabricate patterned polymer sheets and multilayers with a wide variety of geometries, material properties, and responses to stimuli. Here, we will focus on the opportunities presented by multi-layer polymer films. In one case, we focus on developing strategies to control the swelling-induced shape of thin polymer sheets through tailoring of the target mean and Gaussian curvatures prescribed by contrasts in degree of swelling and stiffness of the constituent materials.  In another case, we design photonic multi-layer films that yield tailored optical changes in response to specific environmental changes or analytes.