Human Tears Are Now Powering Medical Devices
The electronics have scaled down in size in the last couple of years, and we’re incredibly close to developing bionics—the integration of biological systems with electronic components and technologies. One of the few things slowing us down is batteries—implying that we would have to charge and change the batteries in our bionics. To that end, researchers in Singapore have found a way to harness human tears and convert them into energy.
According to The Byte, a team of researchers in Singapore has come up with a micrometer-thin (0.001mm or 0.0000393 inches) battery that can store the energy from human tears to power smart contact lenses. Move aside Star Trek, the new era of sci-fi has arrived.
Researchers have found a way to power tiny batteries with human tears.
As it turns out, human tears, like many other bodily fluids, are electrolytic solutions, which means they contain ions (charged particles) that maintain the electrical balance within cells and perform various physiological processes within the eye. This also makes tears capable of conducting electricity.
Why would this be important? Well, the researcher didn’t really focus on harnessing the power of human tears. Instead, they conceptualized this method as an elegant solution for powering smart contact lenses.
Using external batteries is the first thing one might think of, but no one really wants wires sticking out of their eyes. Wireless technology might seem like a viable solution as well, but it’s still years behind on efficiency, and it’s still bulky.
If the inventors ever make a viable prototype of the smart contact lens, it could be used to provide humans with a head-up display, which could overlay necessary information across our field of view. Imagine Google glasses or Apple’s Vision Pro, but instead of sporting bulky hardware, the device would be placed in your eye like a contact lens.
Powering these lenses has proven pretty difficult thus far because the display tech might’ve shrunk to a microscopic degree, but the batteries haven’t. Using external batteries is the first thing one might think of, but no one really wants wires sticking out of their eyes. Wireless technology might seem like a viable solution as well, but it’s still years behind on efficiency, and it’s still bulky.
Using human tears is actually a very elegant solution. The new micrometer-thin battery is made of biocompatible materials and features a glucose-based coating that reacts with sodium and chloride ions to generate electricity and power the circuit inside a smart lens.
Of course, the technology is far from applicable in its current form since the battery has a life cycle of about 200 charge cycles.
As it turns out, human tears contain ions such as sodium, potassium, chloride, and bicarbonate, and a small amount of glucose. The best thing about the whole concept is that human eyes produce tears constantly—we’re referring to basal tears.
This is perhaps the closest we get to actually being bionic, as seen in science fiction since smart lenses would have to rely on the natural resources produced by the human body, such as tears, for power. Not only that, but it would also eliminate the need for bulky batteries or wireless charging, and since they’re biocompatible and glucose-based, they would be less harmful to the environment when disposed of, compared to conventional batteries—which contain harmful and very flammable chemicals.
Of course, the technology is far from applicable in its current form since the battery has a life cycle of about 200 charge cycles. However, the research team is already working with contact lens companies to bring the tech to market.
