Biochemistry.  Ligand chip helps manipulate cells. 
Scientists at the University of Chicago have found an electrochemical way to control interactions between cells and a chip.  It's an improvement over existing methods of influencing cell behavior, none of which allows control over cell-surface activities with chip-bound molecules.  Researchers say the achievement could be a key step toward a wide variety of applications--everything from new drug assays to prosthetic aids that replace damaged neurons.