New miniature sensors designed to warn of chemical dangers here on Earth might one day be worn like badges on space suits to alert astronauts or Martian colonists to dangerous chemicals or elevated radiation levels.

Mars is a wild frontier, with potential dangers that scientists know little about. The Red Planet lacks an ozone layer, which on Earth blocks out lethal doses of solar ultraviolet radiation. This and other forms of radiation change daily and seasonally, but researchers do not yet know how significant or dangerous the problem is.

Future spacesuits will be designed to protect humans against the various risks.

The newly invented sensors, smaller than a dime, might play a role. They were developed by Nicholas L. Abbott of the University of Wisconsin and Rahul R. Shah of the 3M Corporation. A paper discussing their work appears in the Aug. 17 issue of the journal Science.

While scientists already know how to build chemical sensors, current devices are large and bulky, mostly intended for lab use and not practical for carrying around on another planet, let alone wearing.

"These lab methods are extremely sensitive, but they're never going to be the basis for measuring personal exposure," Abbott said. "We wanted to create something that could be worn like a badge."

The newly developed sensors are compact, do not require electrical power and can give direct visual indications, Abbott told SPACE.com. "These features would seem to be useful ones for applications in space," he said.

The sensors are created by what's called nanotechnology manufacturing. They involve microscopic liquid crystals tethered to a thin film of gold by just a few molecules of a chemically receptive substance. When the receptive substance is exposed to certain chemicals, it bonds to the targeted chemical and loosens its grip on the liquid crystal.

The crystals each take on a new orientation that is controlled by the texture of the underlying gold surface, and the combined effect is visible to the naked eye as a change in the sensor's color or brightness.

"We have used rigid substrates, but I don't see a reason that the substrate could not be a flexible polymeric material that is fastened to the outside of a space suit," Abbott said. "I think they could be integrated into clothing of various types."

While the sensors are designed to detect chemicals, Abbott said it would be possible, with further research, to create surfaces that would cause the orientations of liquid crystals to change upon irradiation with ultraviolet light.