User-Friendly Sensors

This article illustrates that miniaturization promises to bring chemical analysis out of the lab and into the field. Current research, based on varying approaches, is aimed at ultimately developing small, portable chemical analysis systems that are fast, accurate, and field-friendly. Some applications have been commercialized, and many more are still under development. One approach, taken by Sandia National Laboratories in Livermore, CA, is based on detecting elemental signatures—telltale traces of elements that fluoresce when the material is hit by an X-ray or gamma ray. An integrated, field-portable µChemLab will take a chromatographic approach to performing chemical analysis on gases and liquids. The enabling technology of Sandia’s approach is based on a new type of solid-state detector designed with a semiconductor crystal alloy of cadmium, zinc, and telluride, which can operate at room temperature—a key advantage over conventional silicon- and germanium-based devices. A different approach, based on chromatography, is the focus of another Sandia project to develop a field-portable chemical analysis device.