Programmable Liquid Crystal Elastomers Prepared by Thiol–Ene Photopolymerization Taylor H. Ware Zachary P. Perry Claire M. Middleton Scott T. Iacono Timothy J. White 10.1021/acsmacrolett.5b00511.s001 https://acs.figshare.com/articles/media/Programmable_Liquid_Crystal_Elastomers_Prepared_by_Thiol_Ene_Photopolymerization/2132032 The spontaneous conversion of a flat film into a 3-D shape requires local programming of the mechanical response. Historically, the ability to locally program the mechanical response of high strain (>30%) liquid crystalline elastomers (LCEs) has been limited to magnetic or mechanical alignment techniques, which limits spatial resolution. Recently, we reported on the preparation of LCEs capable of 55% strain with spatial control of the mechanical response at scales as small as 0.01 mm<sup>2</sup>. Here, we report a distinct formulation strategy to realize programmable stimulus-response in LCEs. Photopolymerization of thiol–ene/acrylate formulations yields materials that exhibit large reversible strain up to 150%. The photopolymerization reaction is extremely rapid, reducing preparation time from days to minutes. The mechanical behavior of these materials can be tuned by varying cross-link density. Spatial and hierarchical programming of the director profile is demonstrated, enabling 3-D shape change, including twisting ribbons and localized Gaussian curvature. 2015-09-15 00:00:00 alignment techniques strain photopolymerization reaction formulation strategy Gaussian curvature director profile material 0.01 mm 2. response programming LCE preparation time Programmable Liquid Crystal Elastomers