Transformative Two-Dimensional Array Configurations by Geometrical Shape-Shifting Protein Microstructures

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• 作者：Chee Leng Lay ; Mian Rong Lee ; Hiang Kwee Lee ; In Yee Phang ; Xing Yi Ling
• 刊名：ACS Nano
• 出版年：2015
• 出版时间：October 27, 2015
• 年：2015
• 卷：9
• 期：10
• 页码：9708-9717
• 全文大小：736K
• ISSN：1936-086X

文摘

Two-dimensional (2D) geometrical shape-shifting is prevalent in nature, but remains challenging in man-made 鈥渟mart鈥?materials, which are typically limited to single-direction responses. Here, we fabricate geometrical shape-shifting bovine serum albumin (BSA) microstructures to achieve circle-to-polygon and polygon-to-circle geometrical transformations. In addition, transformative two-dimensional microstructure arrays are demonstrated by the ensemble of these responsive microstructures to confer structure-to-function properties. The design strategy of our geometrical shape-shifting microstructures focuses on embedding precisely positioned rigid skeletal frames within responsive BSA matrices to direct their anisotropic swelling under pH stimulus. This is achieved using layer-by-layer two photon lithography, which is a direct laser writing technique capable of rendering spatial resolution in the sub-micrometer length scale. By controlling the shape, orientation and number of the embedded skeletal frames, we have demonstrated well-defined arc-to-corner and corner-to-arc transformations, which are essential for dynamic circle-to-polygon and polygon-to-circle shape-shifting, respectively. We further fabricate our shape-shifting microstructures in periodic arrays to experimentally demonstrate the first transformative 2D patterned arrays. Such versatile array configuration transformations give rise to structure-to-physical properties, including array porosity and pore shape, which are crucial for the development of on-demand multifunctional 鈥渟mart鈥?materials, especially in the field of photonics and microfluidics.