Researchers have long pursued the notion of capturing energy from movement of the human body through activities such as walking or running. Until recently, however, energy-harvesting prototypes could not produce enough current to drive electronic devices. Now, the dream of motion-based power is becoming reality.
In February, researchers at the University of Auckland, in New Zealand, announced the development of an energy harvester composed of flexible silicone and a metal coil. As the wearer moves, the device generates current within a magnetic field. While the harvester is more effective than previous technologies, the team says it is only the first step in the creation of a trickle charger capable of powering small sensors and medical devices.
A recently funded Kickstarter offering brings motion-based power closer to the consumer. Ampy is a small, pocket-able device that resembles a portable battery charger. Ampy absorbs and stores energy generated by the movement of its user, and is fitted with a USB port to which devices can be connected for charging. Ten-thousand walked steps will provide three hours’ of juice for a typical smartphone or 72 hours of power for an average fitness tracker. One hour of cycling or 30 minutes of running will generate the same amount of electricity. A companion smartphone app (below) lets users track energy generated.
Created by a trio of Northwestern University materials science and engineering Ph.D. candidates who launched the startup out of the university's Segal Design Institute, Ampy more than tripled its Kickstarter funding goal of $100,000 by the campaign's close on Nov. 9. The interest reveals the popularity of kinetic power generation as a way to combine renewable energy and fitness. The company expects to begin shipping the product in the spring of 2015.
The technology behind devices like Ampy offers a new way to harvest energy not only to people in developed areas but also to those in regions lacking ready access to power. As mobile phones, light fixtures, and medical sensors become more energy efficient and economical, kinetic power has the potential to improve communications, illumination, and healthcare support globally. As an added bonus, whatever the audience, the technology will benefit those who are physically active—which is a good thing, too.
Blaine Brownell, AIA, is a regularly featured columnist whose stories appear on this website each week. His views and conclusions are not necessarily those of ARCHITECT magazine nor of the American Institute of Architects.