The tweezers' action occurs on a common glass microscope slide embedded with five electrodes. These electrodes create an electric field that can be used to push, pull, move and spin a selected object in any direction without actual physical contact. Using software Edwards developed, an operator can select an individual object from a microscope image on a computer screen. "Different types of particles respond differently to different frequencies in the electric field," Edwards said. "Once you lock onto the object of interest you can move it however you like."
The electric tweezers take advantage of the phenomenon known as dielectrophoresis, where electric fields impart a force upon a neutral particle. In essence, the object that is selected surfs atop the hills and valleys created by subtly changing the electric field.