This article discusses how Amy Smith, a mechanical engineer at the Massachusetts Institute of Technology in Cambridge, has turned simple materials into life-changing tools. One of the first was developing a new type of grain mill that could revolutionize the lives of women in the Third World. A motor-driven mill can accomplish the same task in just a couple of minutes, but motorized mills are difficult to come by and expensive to maintain. Smith realized that coming up with a simpler, cheaper mill would be a boon for many families. Often in underdeveloped areas, this grinding must be done by hand, with women crushing the kernels between a rock or mortar and a flat stone or bowl. Smith’s group has developed a clamp for controlling intravenous fluid that could help nurses care for more patients during an epidemic.