RoboBee is a tiny robot capable of partially untethered flight, developed by a research robotics team at Harvard University. The culmination of twelve years of research, RoboBee solved two key technical challenges of micro-robotics. Engineers invented a process inspired by pop-up books that allowed them to build on a sub-millimeter scale precisely and efficiently. To achieve flight, they created artificial muscles capable of beating the wings 120 times per second. The 3-centimeter (1.2 in) wingspan of RoboBee makes it the smallest man-made device modeled on an insect to achieve flight.