Sorting matter with tiny fingers of light

Chicago physicists are set to announce they’ve successfully used multiple beams of light to selectively sort microscopic particles, biological cells and large molecules. Manipulating these beams of light has led to one of the newest techniques in microfluidics, the science of transporting fluids through networks of miniature channels. University of Chicago Physics Professor David Grier calls the new technique “optical fractionation,” because it involves using light to sort one fraction of objects from another.