Invasive operations are routine for complex injuries, but they are also inherently risky. Trucks would be a much better option. Tiny trucks, loaded with drugs. Developed as a prototype, human cell-sized microbots could spare vulnerable areas--such as the spinal column--from surgical injury. "A microbot is like a vehicle that ships drugs directly to the affected area. And I want to design a truck [to be able to carry more drugs], not a car," said Zhang Li, researcher at Chinese University.