As wearable devices become more and more a part of our everyday life, there appears to be one glaring problem: power. Sooner or later, you have to plug your device into the wall for a charge.
However, the days of plugging in wearable devices could be numbered. Scientists are working on technologies that would use the human body’s heat, chemistry, and even sweat to create electric power.
So far, none of these methods can produce enough power to charge an iPhone, but it may only be a matter of time. Check out some of the ways your body could be used to produce electric power.
Biofuel cells
A team at the Joseph Fourier University of Grenoble has created an implantable biofuel cell that draws power from two substances that are freely available in the human body (glucose and oxygen). The cell is made of two special electrodes. One has the ability to remove electrons from glucose. The other donates electrons to molecules of oxygen and hydrogen. When the two are connected to a circuit, they produce a flow of electrons from one electrode to the other, which creates an electrical current.
Since glucose and oxygen are both abundant in the human body, a biofuel cell could continue to produce electricity for as long as the body remains alive.
Researchers have tested the cell in a rat, which continually produced power for 40 days while having no visible side-effect on the rat’s health or behavior. This proved the concept, but due to the rat’s small size, the amount of electricity produced was quite low. The next step is to try a cow, which should produce enough energy to actually power some artificial devices.
Researchers are also working on a new version of the cell that will produce 50 times the power of the current model. If successful, the cell could be used to power artificial limbs and organs.
Sweat
When humans exercise vigorously, they produce lactate, which is present in their sweat. Researchers from the University of California, San Diego have developed a small temporary tattoo that can be worn during exercise that is equipped with an enzyme that strips electrons from lactate to generate an electrical current.
The amount of power generated was quite low, only 70 microwatts per sq cm of skin. However, developers are working on increasing the power output by either making the device more sensitive to lactate or expanding the size of the device.
If they succeed, we could soon be powering our fitness trackers and other devices with our own sweat.
Body heat
A team of researchers at Korea Advanced Institute of Science and Technology University in South Korea have created a lightweight, flexible thermoelectric generator that converts the temperature difference between the wearer’s body heat and the surrounding air to electrical energy.
The device only produces 40 milliwatts of power, which is the weakest of the options discussed in this post. However, like the other methods, the team is working on improving the device.
Which device will be the first to turn the human body into a battery? Time will tell.
