(Posted October 22, 2001)

HUNTINGDON, Pa. -- Remember when Captain Kirk manned the helm of the Starship Enterprise and commanded Ensign Sulu to grab some nefarious alien spaceship in the grip of the ship's tractor beam? Well, two Juniata College physics professors are using a high-powered laser to do the same thing -- that is, picking up and moving objects using the power of light.

Jim Borgardt, assistant professor of physics, and Jamie White, associate professor of physics, have established a laboratory that uses "optical tweezers," which is simply a single beam of concentrated laser light that can latch onto and move microscopic items.

"You can use a single laser beam to trap a particle in three dimensions," Borgardt explains. "The use of optical tweezers exploits the fact that light can apply pressure and force to an object. As the light is concentrated, the force applied by the laser is strong enough to hold an object in place and manipulate it."

Currently, Borgardt, White and George Gehring, a junior from Reading, Pa. studying physics, are using the laser tweezers to manipulate microspheres, which are tiny latex spheres (about 5 microns or five-millionths of a meter) that are used in science to calibrate microscopes and for various other applications.

"Right now we're just using the microspheres as practice material to get used to manipulating the laser," White says. "We also have started working with biological materials such as red blood cells."

Gehring currently is researching how to manipulate red blood cells to test their surface morphology -- what happens when a cell is pushed inward or against another cell. "The smaller the particle, the easier it is to trap," Gehring says. "Eventually the use of laser tweezers should have many uses in medicine and cellular research."

Borgardt says that Juniata students will use the laser lab for simple biology and physics research, such as measuring the force the laser is applying to the microspheres, testing the surface tension of blood cells and measuring the tensile strength of muscle fibers.

"Eventually we would like to use the lab to study how a virus enters or infects a blood cell," White says. "Using the laser lab, you don't have to mix a large amount of cells together with viral material to see a reaction. You can manipulate the microscopic material to see the reaction as you observe."

Borgardt and White will use the laser equipment, which is roughly 10 times stronger than a supermarket scanner and costs about $8,000, to teach Juniata's classes in advanced physics and microscopy. "As more students use the laser, research should go in the direction of biological physics -- working with plant and animal cells," Borgardt says. "We want Juniata science students to use the lab to tap into their own interests."

Eventually, the college's physics department would like to invest in an infrared laser, allowing researchers to more easily manipulate cellular material. In addition, infrared lasers do not emit as much energy as visible lasers. "The laser we have now allows us to move and manipulate blood cells, but if you leave them in the beam for too long, the cells begin to disintegrate." Gehring says. "Infrared lasers give you the opportunity to study plant and animal cells without destroying the material as quickly."

Contact April Feagley at feaglea@juniata.edu or (814) 641-3131 for more information.