In 2006, undergraduate Brian Kaminski was building his senior design project: a glove to help stroke victims regain hand function. He needed a sensor to detect the electrical impulses sent to muscles, but he couldn’t find one for less than $1,000. Kaminski dropped the glove project, but the idea of a cheap muscle sensor stuck with him. Five years later, he created one. “I decided to hand-solder a few circuit boards and put them up for sale, thinking I would get only a few orders a month,” Kaminski says. He was soon scrambling to keep up with demand.