A point-and-shoot portable instrument to protect people and the environment is a product of some 20 years of research by the Department of Energy’s Oak Ridge National Laboratory (ORNL) scientist Tuan Vo-Dinh.
The instrument, dubbed RAMiTS (RAMan Tuneable Integrated Sensor) analyses chemicals in seconds and is the first battery-operated portable device with tuneable filters. Its performance is said to be comparable to that of laboratory-scale instruments.
RAMiTS uses Raman technology, employing a helium neon laser, acousto-optic tuneable filters and a photo sensor to detect toxic chemicals, TNT, by-products from explosives, drugs and hundreds of chemicals. The material can be in liquid or powder form.
Raman technology involves illuminating a sample with a laser beam and measuring the reflected light. The light shows the vibration energies, which are unique to each compound in the sample, and that information helps scientists identify the substance. It’s a technology that, until the development of acousto-optic tuneable filters, was impractical for use in the field.
An acousto-optic tuneable filter is a solid-state optical bandpass filter that can be tuned to various wavelengths.
‘The recent development of acousto-optic tuneable filters has made the use of Raman technology practical for applications in a variety of environments,’ said Vo-Dinh.
Operation of the instrument is simple, according to Vo-Dinh, who noted that he and colleagues designed it to be used by people with no special skills. The user points a probe at the substance to be tested and touches the start button on the touch-screen display.In 11 seconds, the prototype instrument, dubbed RAMiTS (RAMan Tuneable Integrated Sensor), provides a spectral analysis.
Vo-Dinh envisions RAMiTS being used to monitor environmental pollution, detect chemical agents, and inspect meat and other food products more quickly and accurately than is possible with conventional technologies.
Its potential uses for medical applications, ranging from screening for diseases to diagnostics, are also significant, concluded Vo-Dinh.