Camera for Capturing Polarized Light in Deep Space Inspired by Moth Eyes

Innovation: Industry

NASA

2016

Image: Wolfgang Hasselmann / Unsplash / CC BY SA - Creative Commons Attribution + ShareAlike

Modify Light/Color

Color in living systems comes from pigments and the interaction of light with surfaces. Color serves many purposes for living systems, such as attracting prey or mates, providing warnings, or protecting through camouflage. To create the effects needed for each purpose, living systems must control the expression or visibility of pigments and the interactions (such as reflectance and refraction) of light. To do so, they have strategies that modify color or light to increase or decrease the color’s position, intensity, opacity, and more. Male hummingbirds, for example, have brightly colored feather patches on their throats; the coloring comes from pigments, structures that refract light, or a combination of the two. When a male hummingbird hovers near a potential mate, it modifies the angle of these feathers to create a bright, colorful display. However, when it needs to mute the colors to reduce conspicuousness, such as to avoid a predator, it modifies the angle again.

Search this Function

HAWC+ from NASA is a telescope camera with small protuberances on the surface that increase light capture.

Benefits

Increased light capture

Applications

Cameras

UN Sustainable Development Goals Addressed

Goal 9: Industry Innovation & Infrastructure

The Challenge

Capturing infrared light is the only way to view many cosmic objects, including the early stages of star, planetary, and galaxy formation. As the light from the most distant objects travels through the universe, it’s stretched by the expansion of space. By the time the light reaches Earth, that stretching process has transformed short wavelengths of visible and ultraviolet light into the longer wavelengths of infrared light. Only telescopes that can detect infrared light can see those faraway objects. These telescopes have cameras that need to detect and absorb infrared light. The more sensitive the camera, the more light it can absorb and the more objects we can see.

Innovation Details

The HAWC+ has a silicon structure containing thousands of tightly packed, micro-machined spikes or cylindrical protuberances no taller than a grain of sand, which inspired by the structures on the surfaces of moth eyes. These structures help to increase capture of far-infrared light and even detect minute variations in the light’s frequency and direction.

These images taken with a scanning electron microscope show details of the surface of the HAWC+. The “spikes” were inspired by the structure of a moth’s eye. Photo: NASA.

Biological Model

Moths hunt at dusk or at night when limited light is available. In order to maximize light capture, moth eyes are covered with a regular pattern of conical protuberances, generally 200-300 nm in height. These structures dramatically minimize light reflection over a broad range of wavelengths. This is because the protuberances are graded rather than polished, causing most of the incoming light to bend at the surface and be transmitted through the eye, rather than reflecting off it. These structures also help to create a barrier against dust and dirt.