Solar cells inspired by moth eyes

Philips Research Laboratories engineers have taken inspiration from moth eyes to develop a coating for solar cells that increases their efficiency. Nanostructures, comparable to the tapered structures on the insects' eyes, reduce the amount of light that's reflected off the photovoltaic material. From Physics World:

To maximize the amount of light entering (moths') eyes, to help them see at night, the insects' eyes are covered in tapered nanostructures. This creates an "effective medium" where the refractive index gradually increases as light travels from air through to the insects' optical nerve. The resulting effective index is close to one, which means that very little light is reflected out of the eye.

Inspired by these biostructures, Gomez Rivas and colleagues have mimicked the effect by growing nanowires of different lengths - creating a metamaterial with optical properties that change gradually as a function of distance.

"Moth eyes inspire more efficient solar cell" (via Daily Grail)

[#1 posted by Takuan, February 10, 2009 1:58 PM]

can't beat nature for a subtle shift in gradient. remember the squid beak hardness to water-like softness range?

[#2 posted by Takuan, February 10, 2009 2:00 PM]

speaking of which, is the current tech in starlight scopes now nanofilament? Last I looked they were using fused optical fibers.

[#3 posted by Guysmiley, February 10, 2009 2:40 PM]

The latest "GEN III+" NVDs use a gallium arsenide photocathode and a gated power supply that allows for instantaneous changes in light conditions (no longer get blinded by a light source).

[#4 posted by Sethum, February 10, 2009 5:27 PM]

Nature has so many lessons to teach us. This and the gecko's sticky pads are my two favorite. Reason #187 for taking care of our planet.

[#5 posted by ackpht, February 10, 2009 10:05 PM]

Electromagnetic impedance matching, moth-style.

[#6 posted by Anonymous, February 11, 2009 9:29 AM]

If you are interested in other examples of, or inspiration for biomimicry, take a look at our newly launched site:

http://asknature.org/

We have pages for anti-reflective moth eyes, as well as many other natural strategies that can be applied to engineering and design.

http://www.asknature.org/strategy/b389c40f5c8660fc082282bac3e00c3f