[Abstract] The body's own energy can be used to charge small electronic devices carried around, and sweating also generates electrical charge.
Human Generator: Turn Your Body into a Power Source
Humans engage in numerous activities, but the energy generated often dissipates silently into the universe. Researchers and entrepreneurs see this as a tremendous waste, which is why they tirelessly search for ways to harness this energy. Why not use the body's own energy to charge small, portable electronic devices?
Sweat power generation
Even simple activities like sweating generate electrical charge. Researchers at the University of California, San Diego, have designed a sensor similar to a temporary tattoo that can generate electricity from sweat. How does it do this? It detects and reacts to lactate, a chemical produced during glycolysis, a process that occurs during strenuous physical activity. Detecting lactate levels isn't new; professional athletes have been using this method to understand the effects of exercise. However, this latest tattoo-like sensor also contains an enzyme that extracts electrons from lactate, generating a small amount of electricity under certain conditions.
Because of its small size, a less robust person can only generate a maximum of 4 microwatts of electricity, less than half the power required by a watch. However, it's easy to imagine that if the tattoo were made larger, the efficiency improved, or this function were integrated into clothing, this bio-powered technology could potentially power smartphones.
mouth power generation
But you might prefer to sit quietly somewhere and enjoy a sandwich. No problem, engineers at the Montreal école de Technologie Supérieure have developed a special chin rest that converts the energy from your chewing into electricity. Their goal is to power hearing aids or other small devices in this way. The belt is made of piezoelectric fiber composite material (PFC), which, thanks to the piezoelectric effect, converts the energy generated when stretched into electrical energy to power electronic devices.
The prototype is somewhat bulky; chewing gum for 60 seconds generates only 18 microwatts of electricity, roughly 1/20th the power required by a hearing aid. However, they say that simply adding a few layers of straps can increase the power. They hope that people who frequently wear helmets (including cyclists, firefighters, and miners) will one day find practicality in this "extra joint."
Almost simultaneously, researchers at Cranfield University in the UK used the same piezoelectric fiber composite material to create a military device that could convert the swaying of a soldier's backpack during a march into electrical energy, making it a self-sufficient power plant.
Footprint power generation
In a favela in Rio de Janeiro, Shell sponsored a project developed by Pavegen Systems to generate electricity from the power of running—specifically, the power of 22 football players running back and forth. The company has added 200 energy-harvesting tiles to the stadium, generating electricity with every step. Combined with solar panels, the entire stadium can provide up to 10 hours of lighting when fully charged. It was reported that when the stadium opened last September, football legend Pelé was moved to tears at the opening ceremony.
If you think Pavegen's technology can be used in other high-traffic areas, the company is actually one step ahead: they have already installed these tiles in several schools, a subway station in France, a shopping center in Australia, and London Heathrow Airport to power LED lighting systems and mobile phone charging ports.
How wonderful it would be if such a product could be installed in Tokyo subway stations or Times Square in New York to power the surrounding large screens!
