Scientists are on the verge of a revolution in biomedical engineering that will forever change the way we think about medicine, even life itself. Biomedical engineering isn't new. Humans have been tinkering with ways to supplement, repair, or replace body parts for thousands of years. The oldest known prosthesis, a wooden toe, was found on an ancient Egyptian mummy. But now, cutting-edge researchers are working to build body organs and tissue in the lab. They are developing ways to encourage the body to regenerate damaged or diseased bone and muscle tissue. Scientists are striving to re-route visual stimuli to the brain to help blind people see. They may soon discover methods to enlist the trillions of microbes living in our bodies to help us fight disease. Learn about four strands of bioengineering—tissue engineering and regenerative medicine, neuroengineering, microbial science, and genetic engineering and synthetic biology—and meet scientists working in these fields.