Breakthrough in Wearable Devices: Your Body Converted to Battery!

“Off! Ugh! The summer this time is too hot man.”

“I need to charge my smart-watch soon”.

Can these two phrases be relatable? Can they lead to some interesting innovative tech?

Well! Science has always been interesting and so is the field of wearable devices these days. A lot of research is going on each day in this area and lot of technology is developing everyday. Let me relate those two phrases first…

“Your body heat can be converted to electricity to charge your smart-watch”.

This sounds fictional. Fiction to reality is science and researchers at University of Colorado have developed such a tech, which can transform your body into a battery!

Overview of the Tech: Future of Wearable Devices

This is device of the future. Wear it like a ring or as a bracelet or even a whole t-shirt or any other wearable devices stuff which makes contact with skin. The technology gets into a person’s natural heat, engaging Thermoelectric Generators (TEGs) to convert body’s heat into electricity. Thus, we can say that these are some “battery-less” wearable electronics…this is just too cool!

And sustainability is not a problem at all! The device proposed here self-heals itself when damaged and fully recyclable. This makes them cleaner and greener alternative from conventional systems.

Let us first understand what is the core principle involved in this technology. Most of the wearable devices use a component called Thermoelectric Generators (TEGs). What are they?

Well, these are small, compact and most useful thing fitted on the tech. They convert heat flux (simply called temperature differences) directly into electrical energy. They are made up of materials which have high electrical conductivity and low thermal conductivity. Nanotechnology plays a major role while fabricating them into wearable devices, as they need to be small yet efficient. Without getting much deeper into this particular component, consider that this is the most promising energy sources in the field of wearable electronics and in the growing field of Internet of Things (IoT).

With such goodies, there are some things which make them less feasible. Rigidity, brittleness and inflexibility are some factors which restrict their use. However, now for the first time these things have been overcome, and a self-healable and recyclable TEG is introduced; with super flexibility and superior stretchability. Using advanced thermoelectric films, fibers and/or organic materials, the whole component was synthesized with record-high open-circuit voltage (1 V/cm²) amongst all other TEGs.

Getting into the skin

For knowledge and information enthusiasts, let me give specific details of this wearable devices innovation. The TEG system is configured by integrating high-performance modular thermoelectric chips, dynamic covalent thermoset polyimine as substrate and encapsulation, and flowable liquid metal as electrical wiring through a novel mechanical architecture design of “soft motherboard-rigid plugin modules” (SOM-RIPs). These all work together to give TEG system Lego-like reconfigurability which allows its users to adjust and customize the energy-harvesting device as per the thermal and mechanical conditions.

Thermoelectric chips are fabricated by depositing thin film Bismuth (Bi) and Antimony (Sb) chalcogenides onto polyimide films using thermal evaporators; which serve as n-type legs and p-type legs. To improve the crystallinity and performance of the chip, the thermoelectric films were treated at 320^oC for 26 min in argon atmosphere. And lastly, Au-Ge electrodes were deposited using a thermal evaporator to form a connection between n and p type legs.

Sorry about the previous paragraphs, got to cringey. But the final product of all these is as soothing as a diamond ring, I must say. It appears a beautiful cross between a bracelet and a miniature computer motherboard. So, next time when you go for a stroll, or a tiring jog; avoid wearing fancy bracelets and costly rings. Wear the future. Wear the wearable devices’ innovation. A perfect device for all (rather all hard workers) which converts body heat into electrical energy.

This all sounds big, while the real chemistry is small and minute. The bond exchange reactions happening within the dynamic covalent thermoset polyimine network and flowable liquid-metal electrical wiring – makes the whole wearable electronics technology unique. It becomes self-healable, recyclable and Lego-like configurable. With excellent mechanical properties, it can be stretched and worn on finger, while functional.

The Positives of this wearable devices

Consider you have gone for a jog or a brisk walk. Exercise makes your body to heat up and that heat will radiate out to the cool air around you; means becomes of no use. Now, this wearable device captures that heat, preventing it from dissipating and TEGs utilize it to generate electricity. Thus, your body just got converted into a battery (rather pseudo battery).

Using this device, an average person taking a brisk walk can generate about 5 volts of electricity, that too from just a size of an ordinary sports wristband. And believe me, this much amount of electricity is much more than what many watch batteries can muster.

The Most interesting part comes now!

While wearing it, if the device breaks down or tears up, just pinch together the broken ends of it and they will seal back up in no time. Okay, so you must be thinking, “what if I am fed up wearing the wearable devices?”

No worries, researchers got answer to this too. Just put it in a special liquid solution. This will separate out the electronic components, and dissolve the polyimine base. And thats it! Now each and every component can be reused potentially. With such fascinating things, the wearable devices like this can become fully commercial in next 5 to 10 years…or may be sooner! as reported by one of the researchers.