CORNELL UNIVERSITY IMAGE: A SCANNING ELECTRON MICROSCOPE IMAGE SHOWS A CELL-SIZE ROBOTIC SWIMMER THAT CAN BE POWERED AND STEERED BY ULTRASOUND WAVES. CREDIT: CORNELL UNIVERSITY ITHACA, N.Y. — Scientists at Cornell University have created cell-size robots that can be powered and steered by ultrasound waves. Despite their tiny size, these micro-robotic swimmers – whose movements were...