Seventeen-year-old GauravJit Singh is a maker of prosthetic arms. And he's been doing it already for seven years, since he built the first prototype out of straws and yarn, as a sixth grader. Now, a senior at Montgomery High School in New Jersey, and an EMT, GauravJit has created the first EMG controlled hand that allows for individual finger movements using electrical sensors attached to the user's arm. GauravJit believes in doing-it-yourself when it comes to biotechnology.