Laboratory scientists develop novel fluorescent thermometer

Contact: Todd Hanson, tahanson@lanl.gov, (505) 665-2085 (04-028)

Recent News Los Alamos scientist named Asian American Engineer of the Year Los Alamos scientist featured in NASA science update Los Alamos muon detector could thwart nuclear smugglers Wojciech H. Zurek named Phi Beta Kappa visiting scholar Four Los Alamos physicists honored by American Physical Society Los Alamos National Laboratory organizations earn seven out of 13 NNSA Pollution Prevention awards Carter Hydrick returns to the Bradbury Science Museum Feb. 15 Laboratory supports summer science program New NASA IBEX mission to carry Los Alamos instrument Beason takes top threat reduction post at Los Alamos

LOS ALAMOS, N.M., April 15, 2004 -- University of California scientists working at Los Alamos National Laboratory have developed a fluorescent material that responds rapidly and reversibly to temperature. The material could be the basis for highly sensitive optical thermometers useful in biological monitoring, medical, industrial and security applications.

Although molecule-based optical thermometers have received a great deal of attention recently, most have limited operational ranges on the order of only a few degrees. The Los Alamos thermometer is accurate to one-tenth of a degree and responds to temperature changes ranging from 77 to 284 degrees Fahrenheit, giving it a wider temperature range than any existing fluorescent thermometer.

The new thermometer employs a luminescent molecule--a luminophore--within an ionic liquid. The smallest drop of the ionic liquid contains trillions of these individual molecular reporters. When the luminophores are illuminated with ultraviolet light, one of its components glows in the ultraviolet (375 nanometer) range of the visible spectrum and another component glows a different--blue--color near 475 nm. The relative intensities of these two bands of light changes dramatically with temperature, thereby creating a color that corresponds with specific temperatures.

According to Laboratory scientist Sheila Baker, "this kind of optical thermometer has the potential for use on so many scales--large and small- that we have only just scratched the surface of its countless possible applications. For example, when used in a manufacturing setting, the molecular thermometer's real-time monitoring capability may help to optimize industrial processing leading to waste minimization and energy conservation. On the microscale, this technology could be used for mapping temperature in lab-on-a-chip and microelectromechanical systems and for locating heat bottlenecks in integrated circuits.

When coupled with flexible fabrics, a reliable bedside and battlefield temperature monitoring device could be created."

In addition to Baker, Los Alamos Frederick Reines postdoc Gary Baker, and technical staff member T. Mark McCleskey worked on the development of the thermometer. The researchers are currently working to advance several promising applications, as well as encapsulating the material to create temperature-sensitive paints.

Note to news media/editors: Click here for photo. Photo credit: Los Alamos National Laboratory/Leroy Sanchez

Los Alamos National Laboratory is operated by the University of California for the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy and works in partnership with NNSA's Sandia and Lawrence Livermore national laboratories to support NNSA in its mission.

Los Alamos enhances global security by ensuring safety and confidence in the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction and improving the environmental and nuclear materials legacy of the cold war. Los Alamos' capabilities assist the nation in addressing energy, environment, infrastructure and biological security problems