Cheng Luo, an engineer from the University of Texas at Arlington, has created a self-propelled microboat based on the toy boats he played with as a child. When an object -- say, a toy boat -- floating on water has a drop of oil on it, the change in surface tension propels that object in the opposite direction. With this principle in mind, Luo has created a microboat that measures just millimeters, contains its own reservoir of isopropyl alcohol as a propellant, and cruises at around 30 cm per second. "But, why?" you ask. Luo explains that these tiny boats could be used to deliver drugs in blood vessels or even to diagnose and treat ailments. Sounds good to us -- wash one of these down with some self-healing goo and you could be all set. But before we go, try saying "toy boat" three times really fast.