Tunable and Responsive Structural Color from Polymeric Microstructured Surfaces Enabled by Interference of Totally Internally Reflected Light

This report describes a straightforward and versatile approach to the fabrication of polymer films composed of microscale dome or well features that create structural color by interference from total internal reflection. The fabrication approach utilizes assembly of glass particles at monomer oil-oil 1, n=1.64 water interfaces, providing control over the radius of curvature and contact angle of the resultant microstructures. The influence of the microscale concave interface geometry and refractive index contrast on the structural colors produced is systematically investigated, and the results are compared with those predicted by optical modeling. By dynamically changing such parameters, for example, by deforming the surfaces with mechanical force or using temperature to change refractive index, stimuli-responsive color-changing surfaces and structurally colored patterned images are demonstrated. This simple design and fabrication method to produce structurally colored surfaces may be of interest for both fundamental and applied research areas such as dynamic displays, anticounterfeiting technology, and colorimetric sensors.