David McIntyre and other physicists who study laser “tweezing” use mirrors and other devices to guide a beam into vacuum chambers where the light can trap molecules for study.
Lasers scan our groceries, print documents and play CDs. Surgeons use them to cut and cauterize, and metal workers use them to slice and weld. OSU physicist David McIntyre uses them to trap and manipulate micron–sized particles, taking advantage of a laser–based phenomenon known as "optical tweezing."
Scientists have long known that light exerts force. In recent years, biologists have used it to measure the properties of DNA, proteins and cells. Now, McIntyre and other physicists are experimenting with the ability of lasers to hold and study smaller particles such as carbon nanotubes and cellulose nanocrystals.
"We focus a laser beam through a microscope, and that very small spot of light acts sort of like a magnet for particles," says McIntyre. By enabling scientists to hold and study particles, lasers have become essential tools in developing nanotechnologies.
An affiliate of the Oregon Nanoscience and Microtechnologies Institute, McIntyre coordinates research in a field known as nanometrology, the measurement of nanoscale phenomena, with researchers at OSU, Portland State University and the University of Oregon.