Abstract: A pigment comprising a plurality of photonic crystal particles dispersed in a medium, each photonic crystal particles containing a plurality of spectrally selective absorbing components dispersed within each photonic crystal particle that selectively absorb electromagnetic radiation without substantially absorbing electromagnetic radiation near a resonant wavelength of each photonic crystal particle, wherein each photonic crystal particle has a predetermined minimum number of repeat units of a photonic crystal structure, wherein the predetermined minimum number of repeat units is related to the resonant wavelength, the full-width at half maximum of the resonant wavelength, and the refractive index contrast in the photonic crystal.

Abstract: A structurally colored pigment is described that contains a plurality of photonic crystal particles dispersed in a medium, where each photonic crystal particles contains a plurality of spectrally selective absorbing components dispersed within the photonic crystal particle. In certain embodiments, each photonic crystal particle has a predetermined minimum number of repeat units of the photonic crystal structure. The structurally colored material provides improved reflectance, long-term stability, and control of the desired optical effects. The fabrication techniques described herein also provide high throughput and high yield allowing use in wide ranging applications from cosmetics, paints, signs, sensors, to packaging material.

Abstract: A system and method to measure properties of a liquid, comprising: a colorimetric sensor comprising a photonic structure that displays a first signature upon exposure to a sample liquid that wets at least some of the interior surfaces of the porous photonic structure and displays a signature different from the first signature as the sample liquid evaporates. The system further includes a device to capture changes in the color of the colorimetric sensor; a memory to store data generated by the device; and a processing unit to analyze the data captured by the device. The processing unit compares the data captured by the device with a reference data, wherein the reference data comprises information regarding a time-dependent response of the colorimetric sensor upon exposure to and removal of a first set of predetermined liquids and to output information regarding the sample liquid.

Abstract: A structurally colored pigment is described that contains a plurality of photonic crystal particles dispersed in a medium, where each photonic crystal particles contains a plurality of spectrally selective absorbing components dispersed within the photonic crystal particle. In certain embodiments, each photonic crystal particle has a predetermined minimum number of repeat units of the photonic crystal structure. The structurally colored material provides improved reflectance, long-term stability, and control of the desired optical effects. The fabrication techniques described herein also provide high throughput and high yield allowing use in wide ranging applications from cosmetics, paints, signs, sensors, to packaging material.