Programmable Liquid Crystal Elastomers Prepared by Thiol鈥揈ne Photopolymerization

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• 作者：Taylor H. Ware ; Zachary P. Perry ; Claire M. Middleton ; Scott T. Iacono ; Timothy J. White
• 刊名：ACS Macro Letters
• 出版年：2015
• 出版时间：September 15, 2015
• 年：2015
• 卷：4
• 期：9
• 页码：942-946
• 全文大小：315K
• ISSN：2161-1653

文摘

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 mm². Here, we report a distinct formulation strategy to realize programmable stimulus-response in LCEs. Photopolymerization of thiol鈥揺ne/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.