She/Her. Scientist. Educator. Maker. Learner. Entrepreneur. Mom. Wife. Nerd. Author: The Big Book of Maker Camp Projects. 2021 MakerCamp Director for Make:. View more articles by Sandy Roberts The FlexVolt biosensor for EMG Every time a muscle moves, it generates a tiny electrical signal. For years doctors and scientists have been able to measure those signals using surface electromyography (EMG).