Pedestrian-Powered Medical Devices?
- Friday, 24 May 2013
It could happen someday, say a group of mechanical engineering students at Rice University, Houston, TX. As a project required for graduation, four seniors created PediPower shoes that extract and store energy with every step to power portable electronics and, maybe even medical devices.
Cameron, a Houston-based international company, approached the students regarding the project. The company primarily works on the macroscale providing flow equipment, systems, and services for the oil, gas, and process industries, but asked the students to look into microscale green energy technologies.
So the student team decided to create a shoe-mounted generator. Working with the Motion Analysis Laboratory at Shriners Hospital for Children in Houston, the team determined the force at the heel delivered far more potential for power than any other part of the foot.
Their devices, as currently designed, are too big for day-to-day wear, but the prototypes developed met the benchmarks set by Cameron, delivering an average of 400 milliwatts, enough to charge a battery, in benchtop tests sending energy through wires to a belt-mounted battery pack. A voltage regulator keeps it flowing steadily to the battery.
The PediPower hits the ground before any other part of the prototype shoe. A lever arm strikes first. It is attached to a gearbox that replaces much of the shoe’s sole and turns the gears a little with each step. The gears drive a motor mounted on the outside of the shoe that generates electricity to send up to the battery.
For now, the team would like to provide enough power for cellphones and other portable electronics. But, Cameron has partnered with the Texas Heart Institute to apply its expertise in moving fluids to a new generation of artificial heart pumps, and the students hope their work will contribute to that goal.