Nanoparticle Detection Using Microplasma

Tufts University, Medford MA

Investigators

Abstract

CBET-0755761 Hopwood Microplasmas could provide a benign and economical alternative to radioisotopes for monitoring airborne nanoparticles in the environment. Such monitoring is presently difficult and expensive. However, it is crucial for assessing potential health effects of synthetic and naturally occurring nanoparticles. Present nanoparticle detection systems rely on radioisotopes, but these systems are too large and costly for practical use outside of the laboratory setting, in addition to the health, environmental, and security issues that surround the use of radioisotopes. This research project seeks to develop fundamental knowledge of the charging and de-charging of nanoparticles in pulsed microplasmas. A microplasma is a microscopic region of ionized gas; for example, a single pixel in a plasma television is a microplasma. Such microplasmas could replace the use of radioisotopes for charging nanoparticles electrically, which is done so they can be detected and classified by size. Laboratory characterization of microplasmas will be combined with computer simulations. The experiments will determine the electrical charge distribution of particles expelled from a microplasma in order to reveal the science of nanoparticle de-charging. All these fundamental data will then be applied to design and demonstrate a particle detection system that would charge and concentrate particles within a microplasma. The accumulated particles could then be periodically expelled and analyzed according to the microplasma-induced charge state. Replacement of radioisotopes by microplasmas will increase the safety and utility of nanoparticle detection, producing both an economic and societal benefit. The improved fundamental understanding of the microplasma will also strengthen the field of chemical analysis, which is currently beginning to incorporate microplasma devices into analytical chemistry instrumentation. The program strengthens the technological infrastructure by developing human expertise in applied physics at both the undergraduate and graduate levels.