Electronic medical devices such as vital sign monitors, pacemakers and motorized prostheses are relied upon by people with disabilities, the elderly and others. However, all of these mobile devices are powered by batteries, which have limited energy storage, and add additional weight to the devices. Although substantial progress has been made in enhancing battery capacity, power requirements for the mobile devices are increasing faster than the improvements made in battery performance. Human power is an attractive energy source because of the ability for humans to convert food into mechanical power and the high mechanical power outputs attainable by humans. Human power is portable, environmentally friendly, and readily available for power-consuming applications that involve direct human use, such as prostheses. Qingguo Li is part of an SFU research team who has developed a biomechanical energy harvester (BEH) that converts mechanical energy extracted from human movement into electrical energy. Resembling a leg brace, the BEH works by acquiring the mechanical power produced by muscles at the knee joint when the user is walking. The technology is similar to regenerative braking in hybrid gas-electric automobiles; instead of dispersing mechanical energy as heat using conventional brakes, the energy is converted into electrical energy. Li’s goal is to develop a family of energy harvesting devices that can be worn on the body, inserted into motorized prostheses or permanently implanted within the body.