Month: September 2022

COMPLEX CONTROL. "Varying the degree of dispersion of the melanosomes blocks reflectance of the iridophores but not the xanthophores or erythrophores, so the skin appears yellow-red. Color change may also occur because of changes in the spacing of platelets within the iridophores, a phenomenon that has been demonstrated in fish." https://lnkd.in/eR5ehsm View in LinkedIn

CRYSTAL COLORS. "The discovery that iridophore color arose structurally was made in stages. Early workers noted that iridophores contained birefringent bundles of crystalline material arranged in species-specific patterns. With few exceptions, the iridophore crystals from all organisms studied have been purines, predominantly guanine." https://lnkd.in/evvfbKA View in LinkedIn

PHOTONIC CRYSTALS have featured often in this blog a lot, responsible for coloration of iridescent beetles, butterfly wings, peacock feathers, and used by algae as well as chameleons for UV protection. All appear to have ingeniously evolved uniquely and separately. View in LinkedIn

PHOTONIC CRYSTALS cause chameleon color changes. "Chameleons shift colour through active tuning of a lattice of guanine nanocrystals...and a deeper population of iridophores with larger crystals reflect a substantial portion of sunlight." https://lnkd.in/eEphswK View in LinkedIn

TUNABLE PHOTONIC CRYSTALS are at the heart of chameleon color changes. This is a reminder of how little we understand the coloration of these animals. The proximity of the guanine nanocrystals changes according to the excitation of the animal, causing color shifts. How they change the spacing in these crystal lattices remains illusive. https://lnkd.in/eVmgREB View in LinkedIn

GUANINE NANOCRYSTALS, Video of them caught in action changing color. https://lnkd.in/eAiEqbG View in LinkedIn

PHOTONIC GUANINE NANOCRYSTALS also serve the chameleon in thermal protection. The same is true for certain algae. https://lnkd.in/e3hJaJj View in LinkedIn

SEMICONDUCTORS OF LIGHT = PHOTONIC CRYSTALS. "Nanostructured materials containing ordered arrays of holes could lead to an optoelectronics revolution, doing for light what silicon did for electrons. The microelectronics and information revolution is based on the elaborate control of electric currents achieved with semiconductors such as silicon. That control depends on a phenomenon called the band gap: a range of energies in which electrons are blocked from traveling through the semiconductor." https://lnkd.in/eKrjXgP View in LinkedIn

PHOTONIC BUSINESS. "Many researchers greeted the idea of a photonic band gap with skepticism and disinterest when it was first proposed, but today photonic crystals are rapidly turning into big business. Photonic crystals have applications such as high- capacity optical fibers, color pigments and photonic integrated circuits that would manipulate light in addition to electric currents." http://optoelectronics.eecs.berkeley.edu/eliy_SCIAM.pdf View in LinkedIn

NATURE HOLDS THE PATENTS. "All the magic of semiconductors—the switching and logic functions—comes about from controlling the availability of electrons and holes above and below the band gap." https://lnkd.in/eKrjXgP View in LinkedIn