Astronauts or unmanned space vehicles may one day detect and quantitate the gases found on other planets using tiny chemical sensors — each measuring about 100 microns, approaching the width of a human hair—based on a design developed at NIST.
NIST researchers under chemist Steve Semancik (301-975-2606) are collaborating with the National Aeronautics and Space Administration’s Jet Propulsion Laboratory to adapt NIST’s “microhotplate” technology for use in space applications, such as detecting biogenic (produced by living organisms) gases in planetary atmospheres, investigating organic materials on comets for studies of the history of the universe, or monitoring air quality in habitats.
This advanced measurement system already has proven applicable to environmental monitoring and military operations.
A microhotplate is a tiny machined structure consisting of a heater, a metal thermometer/heat distribution plate and electrical contacts, all separated by insulating layers.
Sensing films are deposited on the structures. The device relies on changes in electrical conductance in the sensing film to detect the presence of adsorbed gases. Temperature changes may be used to create response “fingerprints” for different gases. Gas mixtures can be analyzed with sensor arrays of multiple microhotplate devices.
Advantages of a microhotplate for use in space include its small size, light weight, and low power and maintenance requirements. It has the potential to provide almost instant chemical analysis or collect samples over time to detect small amounts of gases.