Space is a tough environment for electronics. A burst of radiation from a solar flare can damage a satellite's delicate circuits and knock years off its working life. Now research by a University of California, Davis, engineering student is pointing the way to more radiation-resistant microchips.

Anne Vandooren, a graduate student in the Department of Electrical and Computer Engineering, studied how heat, gamma rays, X-rays and proton irradiation affect microchips built with silicon-on-oxide (SOI) technology. SOI chips are used for low-power applications such as cell phones, pagers and personal organizers.

Radiation damages microchips by creating electrical charges in the insulation between transistors, said engineering professor Jean-Pierre Colinge, who supervised the project. His laboratory has previously developed ways to build SOI microchips where transistors are in less contact with insulation.

During her research, Vandooren was able to develop a general model of how radiation affects analog circuits. Analog circuits allow digital systems to connect to the real, analog world, Colinge said.

"If we expose circuits to a level of radiation, we know what to expect," said Colinge. This meant that they could design entire systems that were more resistant to radiation damage, he said.

Vandooren carried out irradiation experiments and measurements at the Lawrence Livermore National Laboratory and the Jet Propulsion Laboratory, Pasadena. Other collaborators on the project were the Catholic University of Louvain, Belgium, and the National College of Electronic and Radioelectricity Engineering in Grenoble, France.

Vandooren's thesis was selected as "best dissertation" at this year's College of Engineering commencement ceremony at UC Davis. After being courted by research labs and tech companies, she is now working on a related project for Motorola.