Robocop was literally a human (more like a human corpse) that a too-ambitious tech executive made into a machine with flesh, but turning yourself into a human battery in the future won’t be nearly that morbid.
It sounds almost as fictional as the movie, but mechanical engineer Jianliang Xiao and his team have developed a new (and cheap) wearable gadget that transforms the human body into a bio-battery. This thing relies on thermoelectric generators that convert your body’s natural heat into electricity without any sort of robotic resurrection involved. It is made of a stretchy, self-healing material you can wear as a ring or bracelet to power wearable electronics like watches and fitness trackers without plugging them in.
So how exactly does this device take heat from the body and convert it into electricity? “It works using the Seebeck effect in the thermoelectric generators, which can directly convert temperature differences on the two sides of the devices to electric energy,” Xiao, who recently published a study in Science Advances, told SYFY WIRE.
Your body generates electricity. Everything that is alive has some sort of output, from humans to Venus flytraps, whose ravenous leaf-mouths clamp shut when an unsuspecting fly or other insect accidentally stimulates them and triggers an electrical impulse. Xiao went a step further and designed something that takes advantage of the voltage that results from a significant enough difference in temperature between two terminals. This is the Seebeck effect. With this converter, one terminal is your skin, while the other is a polyimine device that uses whatever volts it can get to keep your smart watch from dying.
As if this was not unreal enough, it won’t suck the energy out of you like the robots in The Matrix did with their human captives, and there is no risk of electrocution because the level of electricity generated is too low—but just enough to power any tech you can wear. The polyimine it is made of, which has been used to design artificial skin before, is also capable of bonding itself back together if any cuts or tears happen.
“Polyimine is an interesting material,” said Xiao, who has worked with it before in an attempt to create his own artificial skin. “Within its polymer network, chemical bonds can break and reform given appropriate environment. When the device is cut broken, new chemical bonds are generated across the interface, healing to cut in a way like our skin.”
The phenomenon that makes this possible is known as bond exchange reaction. When a chemical bond is broken, another molecule seizes the opportunity to latch on to one end, kicking out the other molecule that got detached. Electrical connections also have to restore themselves in a device that is basically a thermoelectric generator. Xiao made this possible with liquid metal. Using a gallium-based alloy as the electrical interconnection was ideal because gallium melts at around 86 degrees Fahrenheit, which is between room temperature and body temperature. Both outer damage and electrical connections will be instantly repaired without any outside intervention.
Basically, the polyimine this gizmo is made out of is as resilient as human skin and, unlike the biological version, doesn’t bleed when broken. That means you can put it on and forget about it. If it’s starting to sound expensive, Xiao also had that in mind, because he wants everyone to be able to plug in without actually plugging in.
“The most expensive part of this device is the thermoelectric modules,” he said. “To reduce the cost, we used thin film thermoelectrics, which can significantly reduce the material usage compared with conventional bulk thermoelectric devices. Our device is also fully recyclable, and because it is self-healing, minor damages will heal with the need to replace it.”
Don’t expect to see this at Best Buy yet. The prototype is nothing short of amazing and borderline sci-fi, but Xiao and his team are still improving on it so it can be available within the next decade. He especially wants to make the power generation more efficient so the wearer can get the maximum electric energy out of it. It is possible to add more blocks of generators to give it a power boost.
If someone figures out a way to make smartphones wearable, the infamous cry of “my phone died” might eventually be a thing of the past.