We provide an overview of our recent advances in the manipulation of wetting in inverse-opal photonic crystals. Exploiting photonic crystals with spatially patterned surface chemistry to confine the infiltration of fluids to liquidspecific spatial patterns, we developed a highly selective scheme for colorimetry, where organic liquids are distinguished based on wetting. The high selectivity of wetting, upon-which the sensitivity of the response relies, and the bright iridescent color, which disappears when the pores are filled with liquid, are both a result of the highly symmetric pore structure of our inverse-opal films. The application of horizontally or vertically orientated gradients in the surface chemistry allows a unique response to be tailored to specific liquids. While the generic nature of wetting makes our approach to colorimetry suitable for applications in liquid authentication or identification across a broad range of industries, it also ensures chemical non-specificity. However, we show that chemical specificity can be achieved combinatorially using an array of indicators that each exploits different chemical gradients to cover the same dynamic range of response. Finally, incorporating a photo-responsive polyelectrolyte surface layer into the pores, we are able to dynamically and continuously photo-tune the wetting response, even while the film is immersed in liquid. This in situ optical control of liquid percolation in our photonic-crystal films may also provide an error-free means to tailor indicator response, naturally compensating for batch-to-batch variability in the pore geometry.
2013
Wetting in Color: From photonic fingerprinting of liquids to optical control of liquid percolation. Proc. of SPIE. 2013;8632 :863201. Publisher's VersionAbstract
Interfacial materials with special wettability. MRS Bulletin. 2013;38 :366-371. Publisher's VersionAbstract
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New Materials through Bioinspiration and Nanoscience. Adv. Funct. Mater. 2013;23 :4398-4399. Publisher's Version
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Inhibition of Ice Nucleation by Slippery Liquid-Infused Porous Surfaces (SLIPS). Physical Chemistry Chemical Physics. 2013;15 :581-585. Full TextAbstract
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Enhancement of absorption and color contrast in ultra-thin highly absorbing optical coatings. Appl. Phys. Lett. 2013;103 :101104. Publisher's VersionAbstract
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Rationally Designed Complex Hierarchical Microarchitectures. Science. 2013;340 :832-837. Publisher's VersionAbstract
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Chemo-Mechanically Regulated Oscillation of an Enzymatic Reaction. Chem. Mater. 2013;25 (4) :521-523. Publisher's Version
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Creating bio-inspired hierarchical 3D–2D photonic stacks via planar lithography on self-assembled inverse opals. Bioinspiration & Biomimetics. 2013;8 :045004. Publisher's VersionAbstract
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Hydrogel-Actuated Integrated Responsive Systems (HAIRS): Creating Cilia-like "Hairy" Surfaces. In: Cambridge, U.K. RSC ; 2013. pp. 162-185.
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Bacterial flagella explore microscale hummocks and hollows to increase adhesion. Proc. Nat. Acad. Sci. 2013;110 (14) :5624-5629. Publisher's VersionAbstract
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Structural Colour in Colourimetric Sensors and Indicators. J. Mater. Chem. C. 2013;1 (38) :6075-6086. Publisher's VersionAbstract
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Rational Design of Mechano-Responsive Optical Materials by Fine Tuning the Evolution of Strain-Dependent Wrinkling Patterns. Adv. Optical Mater. 2013;1 (5) :381-388. Publisher's VersionAbstract
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Buckling-Induced Reversible Symmetry Breaking and Amplification of Chirality Using Supported Cellular Structures. Adv. Mater. 2013;25 (24) :3380-3385. Publisher's Version
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