Scientists say they recently invented the world's tiniest remote—controlled robots. The robots are small enough to sit on the side of a coin. They don't have any power of their own，and they can be controlled from a distance by using lasers（激光器）. The scientists say one day robots like these may be able to work in areas too small for tools. The robots don't move very quickly. But because of their tiny size，they're also not too slow. It takes the robots about 20 seconds to cover 1 centimeter.
Right now the robots aren't all that useful. All they can do is to move，and they need to be in a place where lasers can shine on them to do that. But the scientists say these robots are an important step toward inventing more helpful tiny robots.
The researchers say that one day tiny robots like these might be able to work in very small spaces. It's possible that they could build very tiny machines，or perhaps even travel inside the human body to help do with medical problems.
Using similar building methods，the scientists made a number of different robots，including ones that looked like small insects. John Rodgers，says that their methods allow them to "build walking robots with almost any sizes or 3 D shapes. "
