Spray-on solutions have found a place in green technology and even in transmitting radio waves, and they're no strangers to medical research, either. Researchers at the British Heart Foundation are working on a bioelectric spray composed of heart cells to help mend that most vital of organs. Because the cells need to be extremely thin to form a sheet of heart tissue, they are passed through a conductive needle that charges them with up to 30,000 volts. Exposing the cells to an electric field turns the solution into small droplets, which in turn form the cardiac sheet. The scientists can also add other types of cells to create "three-dimensional" tissue, which can be grafted onto injured hearts or sprayed onto scar tissue to help patients' tickers pump more strongly. As is so often the case, the next step will be testing the technology on animals, and the project's ultimate goal is to use this spray-on solution rather than making patients wait for donor hearts.