butterflies. An example of bio-inspired photonics using structures is the so-called moth eye. Moths have a structure of ordered cylinders in their eyes that do not produce color, but instead reduce reflectivity. This concept has led to creation of antireflective coatings. A combination of chemical structure and how it interacts with visible light creates color within organisms' nature. The creation of specific biological photonics requires identifying the chemical components of the structure, the optical response created by the physics and the structure's function. The complex structures created by nature can range from simple, quasi-ordered structures to hierarchical complex formations. 2-D Structures Simple Array Structure (Peacock Feathers) Nature sometimes manipulates the nanostructure, such as its crystal lattice parameters in order to create its patterns and colors. The Barbule (the individual strands of a feather that hold its color) of the peacock is made of an outer layer of keratin and an inner layer containing an array of melanin rods connected by keratin with holes separating them. When the melanin rods are parallel to the lattice arrangement of the structure of the keratin outer layer it creates the brown color. The rest of the colors of the feather are created by changing the spacing of the melanin layers. Aperiodic Photonic Structures Aperiodic Photonic Structures do not have a unit cell and are capable of creating band gaps without the requirement of a high index of refraction difference. Also known as quasi-ordered crystal structure creates blue and green coloring. 3-D Structures Helicoidal Multilayers These are twisted multilayers where fibers are aligned in the same direction and each layer they are slightly rotated. This structure allows nature to reflect polarized light and creates an intense value due to Bragg reflection. Application Examples Bioinspired antibacterial structural color hydrogel As a form of application, biophotonics are used in order to indicate antibacterial and self-healing properties. Since the existence of silver nanoparticles prevent bacterial adhesion (there is already bacteria existing in the hydrogel) it causes hydrogel degradation and color fading. This allows for the engineered hydrogel to display with color its integrity after self-healing. Photonic nanoarchitectures in butterflies and beetles Nanoarchitectures contribute to the iridescence of butterflies and beetles. Multilayers are common, typically in a 1-D or 3-D structure, 2-D structures are more rare. Disorder and irregularity in the structure are “intentional” and adapted to the habitat. The structure has been successfully recreated and can be used