Kinetic Energy Harvesters generate electric power simply by walking have been in research. Kinetic Energy Harvesters that convert human power are also called as Biomechanical Energy Harvesters. Biomechanical Energy Harvesters generate small electric power in normal human activities such as while walking, running, regular body movements, etc. Now researchers focusing on portable Kinetic Energy Harvesters that can charge cellular phones, tablet PCs, and other portable gadgets, to enter into the commercial market. That means, in the near future, anybody with a cell phone, iPAD or any other electronic device will never have to worry about batteries again. At least, not as long as they keep moving. Tom Krupenkin and J. Ashley Taylor, energy researchers at the University of Wisconsin-Madison has come up with an energy-harvesting device that captures the clean renewable energy generated by practically anyone merely walking down the street to power if there ever was one.

Current energy harvesting technologies are aimed at either high-power applications such as wind or solar power, or very low-power applications such as calculators, watches or sensors. What’s been missing is the power in the watts range. That’s the power range needed for portable electronics. Solar power, the researchers explain, can also be used to power portable electronics, but, unlike human motion, direct sunlight is usually not a readily available source of energy for mobile electronics users.

Converting Kinetic Energy to Electricity through Electrowetting

inetic Energy Harvesting Shoes Generate Power while WalkingIn their Nature Communications report, Krupenkin and Taylor describe a novel energy-harvesting technology known as “Reverse Electrowetting,” a phenomenon discovered by the Wisconsin researchers. The mechanical energy is converted to electrical energy by using a micro-fluidic device consisting of thousands of liquid micro-droplets interacting with a novel nano-structured substrate.

This technology could enable a novel footwear-embedded energy harvester that captures energy produced by humans during walking, which is normally lost as heat, and converts it into up to 20 watts of electrical power that can be used to power mobile electronic devices. Unlike a traditional battery, the energy harvester never needs to be recharged, as the new energy is constantly generated during the normal walking process.

2-in-1 Shoes-based Mobile Kinetic Energy Harvester

In their work, Taylor and Krupenkin were inspired by severe limitations that current battery technology imposes on mobile electronics users. As any cellphone or laptop user knows, heavy reliance on batteries greatly restricts the utility of mobile electronic devices in many situations. What’s more, many mobile electronics are used in remote areas of the world where electrical grids for recharging batteries are often not available. Cellphone users in developing countries often have to pay high fees to have cellphones charged. Similar problems face military and law enforcement personnel. Modern soldiers, for example, head into the field carrying as much as 20 pounds of batteries to power communications equipment, laptop computers and night-vision goggles.

The energy generated by the footwear-embedded harvester can be used in one of two ways. It can be used directly to power a broad range of devices, from smartphones and laptops to radios, GPS units, night-vision goggles and flashlights.

Alternatively, the energy harvester can be integrated with a Wi-Fi hot spot that acts as a “middleman” between mobile devices and a wireless network. This allows users to seamlessly utilize the energy generated by the harvester without having to physically connect their mobile devices to the footwear. Such a configuration dramatically reduces power consumption of wireless mobile devices and allows them to operate for much longer time without battery recharge, the Wisconsin researchers say.