Close

Search

Search Menu
Photonics Media Photonics Buyers' Guide Photonics EDU Photonics Spectra BioPhotonics EuroPhotonics Industrial Photonics Photonics Showcase Photonics ProdSpec Photonics Handbook
More News
share
Email Facebook Twitter Google+ LinkedIn Comments

Moth’s Eye Inspires Design and Applications of NASA Camera

Photonics Spectra
Apr 2017
GREENBELT, Md. — A moth's eye is the inspiration behind the technology that allows a new NASA-developed camera to create images of astronomical objects with far greater sensitivity than was previously possible.

These images taken with a scanning electron microscope show details of a new absorber that is enabling observations by the High-Resolution Airborne Wideband Camera-plus.
These images taken with a scanning electron microscope show details of a new absorber that is enabling observations by the High-Resolution Airborne Wideband Camera-plus, or HAWC+, a new SOFIA instrument. The "spikes" were inspired by the structure of a moth's eye. Courtesy of NASA.

When magnified, a moth's eye contains a very fine array of small tapered cylindrical protuberances whose job is to reduce reflection. This allows the moth to absorb light making night navigation possible.

The same absorber technology concept, when applied to a far-infrared absorber, results in a silicon structure containing thousands of tightly packed, micro-machined spikes or cylindrical protuberances no taller than a grain of sand. It is a critical component of the four 1,280-pixel bolometer detector arrays that a team of scientists and technologists at NASA's Goddard Space Flight Center in Greenbelt, Maryland, created for the High-Resolution Airborne Wideband Camera-plus, or HAWC+.

NASA just completed the commissioning of HAWC+ onboard the Stratospheric Observatory for Infrared Astronomy, or SOFIA, a joint venture involving NASA and the German Aerospace Center (DLR). This heavily-modified 747SP aircraft carries with it an eight-foot telescope and six instruments to altitudes high enough not to be obscured by water in Earth's atmosphere, which blocks most of the infrared radiation from celestial sources.

NASA recently completed the commissioning of a new airborne camera on NASA's SOFIA aircraft.
 NASA recently completed the commissioning of a new airborne camera on NASA's SOFIA aircraft. This image shows HAWC+ on SOFIA's telescope. Courtesy of NASA/AFRC.

The upgraded camera measures the polarized light from the emission of dust in our galaxy and makes images. With this instrument, scientists will be able to study the early stages of star and planet formation, and, with HAWC+'s polarimeter, map the magnetic fields in the environment around the supermassive black hole at the center of the Milky Way.

Goddard scientist, Ed Wollack said the system can measure minute variations in the light’s frequency and direction.

"This enables the detector to be used over a wider bandwidth. It makes the detector far more sensitive — especially in the far infrared," said Wollack.

Wollack worked alongside Goddard detector expert Christine Jhabvala to devise and build the micro-machined absorbers critical to the Goddard-developed bolometer detectors.

Christine Jhabvala and Ed Wollack hold the sketch of the absorber technology they created.
Christine Jhabvala and Ed Wollack hold the sketch of the absorber technology they created. Containing thousands of tightly packed, micro-machined spikes or cylindrical protuberances no taller than a grain of sand, the absorber is a critical component of the four 1,280-pixel detector arrays used in HAWC+. Courtesy of NASA/W. Hrybyk.

Bolometers are commonly used to measure infrared or heat radiation. When radiation is focused and strikes an absorptive element, typically a material with a resistive coating, the element is heated. A superconducting sensor then measures the resulting change in temperature, revealing the intensity of the incident infrared light.

This particular bolometer is a variation of a detector technology called the backshort under-grid sensor, or BUGS, used now on a number of other infrared-sensitive instruments. In this particular application, the reflective optical structures — the so-called backshorts — are replaced with the micro-machined absorbers that stop and absorb the light.

The team had experimented with carbon nanotubes as a potential absorber. However, the cylindrically shaped tubes now used for a variety of spaceflight applications proved ineffective at absorbing far-infrared wavelengths. In the end, Wollack looked to the moth as a possible solution.

"You can be inspired by something in nature, but you need to use the tools at hand to create it," Wollack said. "It really was the coming together of people, machines, and materials. Now we have a new capability that we didn't have before. This is what innovation is all about."

GLOSSARY
astronomy
The scientific observation of celestial radiation that has reached the vicinity of Earth, and the interpretation of these observations to determine the characteristics of the extraterrestrial bodies and phenomena that have emitted the radiation.
astronomyTech Pulse

Comments
Terms & Conditions Privacy Policy About Us Contact Us
back to top

Facebook Twitter Instagram LinkedIn YouTube RSS
©2017 Photonics Media
x Subscribe to Photonics Spectra magazine - FREE!