Color Materials – Summer Research, 2015
Wallbrights, a modular lighting product, is an LED lighting source, which changes color and intensity and is controlled by your smartphone. The hexagonal lights have an adhesive backing for a variety of options for installation. http://www.psfk.com/2012/10/wall-sticker-lights.html
This is an image of Geometric Dichroic Glass Installations by Chris Wood. http://www.thisiscolossal.com/tags/reflection
An object’s surface is its outermost layer. Smooth surfaces reflect light directly and appear lighter color because much of the light falling on them is reflected back to the eye. Matte surfaces are minutely, sometimes microscopically roughened and diffuse light evenly, so the reflected light is constant from any angle. Textured surfaces reflect light unevenly, scattering light in multiple directions. The same material appears darker with a rough finish than with a smoother finish, while glossy surfaces reflect more light.
Highlighter ink can be used as a black light reactive fluorophore when diluted with water. Remove the base of a marker, take out the core and cut the side with a razor blade. Slowly run water through the core, collecting the resulting ink solution. The colors can be mixed to produce a variety of hues. Luminescence can also be achieved with tonic water, which contains quinine combined with food coloring.
Sensacell is a lighting system that creates interactive architectural environments. LED lighting is combined with capacitive sensors to create essentially a large-scale touch-screen. Large surfaces become interactive components.
OLED is an emerging technology that allows for efficient lighting panels and displays. Thin OLEDs are currently being used in televisions and mobile devices, emerging OLED panels will be flexible and bendable.
In one of the simplest structural colorations light is reflected at the two surfaces and results in interference. It is found in soap bubbles and the coating on sunglasses and binoculars. II-VI Optical Systems is a recognized leader in the application of visible and infrared thin film coatings for a wide variety of substrate materials.
Researchers have used tiny polymer spheres to create structural color thin films. Artificial opals were first created using spin coating techniques, covering flat surfaces of up a meter with an iridescent film.
Bob Grubbs of the California Institute of Technology previously made photonic crystals with brush block copolymers (BCPs) but this ability to precisely tune the wavelength of reflected light is new. When solutions of BCPs evaporate, they self-assemble into one-dimensional photonic crystal structures. This new effect has been achieved by adjusting the ratio of two BCPs used.
Opal is a characteristic material that displays structural color. In biomimetic research, opal is a model material for specific ‘opalescent’ luster (play of color) for industrial applications. The following image is synthetic opal.
Florescent paints are commercially available, Japanese artist Que Houxo performs live paintings using fluorescent paints with black lights.
Iridescence in the Morpho Butterfly is the result of high values of the reflection coefficient at the main reflection wavelength. The Morpho has been the subject of research in optical and nanotechnology applications. The surface of the wing is complex light-interacting dielectric structure creates interference of incoming light from the tree branches, and diffraction of the incoming light from the periodic (grating-like) spacing of the units. The geometrical structure of the wing scale of the Morpho butterfly is the basis of a new material called Morphotex created by Teijin Fibres Limited. It is a structured fiber that can be woven into fabrics that show iridescence.
Iridescent pigments are being developed based on the pearl-like interference. Iridescent pearl luster pigment contains thin flakes of silica with both surfaces coated with TiO2. These materials can be useful for applications in banknotes, cosmetics and paints.
Researchers at the University of Cambridge have developed a synthetic material which mimics structural color in nature, and changes hue when stretched and twisted it promises possible applications in the textile, security, and sensing industries. The textile industry uses highly toxic chemicals to generate color, and uses up to 20 per cent of industrial waste water. ‘Polymer opals’ generate colour from their interior structure, the color is pure and does not fade.
Surrey NanoSystems’ developed Vantablack® a material that can be applied to structures such as aluminum and absorbs 99.96% of incident radiation, the highest-ever recorded. The material reduces stray-light, allowing sensitive telescopes to view the faintest stars, and permit smaller, lighter sources in black body calibration systems. It is the result of a patented low-temperature carbon nanotube growth process.
Structural whiteness occurs when a material scatters all incident wavelengths equally. For structural white material, the scattering centers are aperiodic and are multiply oriented where they interface the air. This structure scatters incident white light back to the observer with a low intensity so the material appears very white.
Photopolymer plates and films are coated in a light sensitive synthetic compound that hardens in response to ultraviolet light. These materials are used in flexographic printing plates and to record holograms.
These colors were created by mixing different molecular weight brush block copolymers. Bob Grubbs of the California Institute of Technology previously made photonic crystals with brush block copolymers (BCPs) but this ability to precisely tune the wavelength of reflected light is new.
When solutions of BCPs evaporate, they self-assemble into one-dimensional photonic crystal structures. Previously the size of the BCP determines the wavelength of reflected light so for each specific wavelength a new BCP had to be manufactured. This new effect has been achieved by adjusting the ratio of two BCPs used.
AmbiKraf is a non-emissive analog fabric rapidly changes color based on embedded semiconductor peltier junctions that are incorporated into fabric. Researchers combined semiconductor heating/cooling technologies and thermochromic ink. The thermochromic inks screen printed on to the fabric and lightweight semiconductor peltier junctions woven into the fabric work as temperature actuators for rapid heating and cooling.