Scientists are making motors tiny enough to deliver medicine from inside human cells and microfibers that are 20 times stronger than steel. The gee-whiz science of nanotechnology has grown from obscurity in the 1980s into a trillion-dollar industry that already produces ingredients for some 1,800 consumer goods, from sunscreen to baby formula, and could transform such products as computer chips, solar cells and military armor. Some experts say the nano-revolution, which draws billions of dollars in government funding, could reorder the global economy. But other experts worry about the safety of nanomaterials. They argue that government regulators — notably the Food and Drug Administration and the Environmental Protection Agency — are not up to the task of ensuring that nanoparticles are safe for public consumption or exposure. What's more, they fear that enemies eventually could use nanomaterials to make weapons of mass destruction. The nanotechnology industry contends, however, that current regulations are more than adequate and that the field's promise far outweighs its risks.