As the presence of mobile devices has become increasingly ubiquitous, a growing number of them have begun to utilize innovative wearable solutions that can double as external power supplies.
A research team from the Chinese University of Hong Kong, for instance, has recently rolled out a slider-crank mechanism, which is capable of utilizing the movements of the knees for power generation to drive wearables and mobile devices.
The mechanism is meant for installation on the user's legs and knees, and is capable of converting the rotary movement of the knees into linear movement, which is much like the function of a piston in a compressor and internal combustion engine.
Image: American Institute of Physics
Weighing 307 grams, the mechanism consists of a rod connecting the knee and leg, a slider on the calf, and a macro fiber composite (MFC). When a person is walking, the rod would move vertically, triggering the reciprocation of the slider. This would result in the bending of the MFC which is connected to the top of the rod and slider, and generate power.
The mechanism can generate 1.6 microwatts of power at a walking speed of 2-6.5 kilometers/hour, which is sufficient for powering a mobile health monitoring device or GPS (global positioning system). The experiment also shows that the mechanism will not pose any long term health-related burdens for users.
Another noteworthy device that is worth mentioning is the power-generation backpack designed by a research team from Queen’s University, which uses the swinging of a pendulum to generate power as people walk.
Image: Royal Society Open Science
The university’s research team has built a nine-kilo backpack model that can be used to power emergency signal devices and GPS, and a 15-kilo backpack model which is needed for charging a mobile phone. The device can be used by scientists or explorers for activities in remote areas. As of now, the research team is still endeavoring to downsize the backpack.
(Collaborative media: TechNews, first photo courtesy of Kevin Neubauer via Flickr CC BY 2.0)