New Tech on the Way: Sweat-Powered Smart Watches & Fitness Trackers

A new, super-absorbent film may be used to transform sweat into electricity and power in wearable electronic devices like smartwatches and fitness trackers.

The research team from the National University of Singapore made a film that can evaporate sweat from the skin and keep people cool while they’re working out.

They explain that this film which could be added to fabrics or shoe lining could be used for powering electronic devices by transforming the moisture into energy.

How Did the Process of Making this Film Go?

According to the team, they made a new wearable energy harvesting device with eight cells. Each of these cells produces around half a volt of energy after moisture absorption. This is sufficient to power a LED bulb, but the tech is still at the proof of concept stage.

The team claims it can be extended to also power watches, fitness trackers, and other wearable tech as it’s being developed further.

As reported in the Nano Energy journal, the experiments for this new film involved the patch that’s able to absorb sweat from the underarms and prevent it from reaching the clothes. According to the leader of the team, Tan Swee Ching, when water evaporates from the surface of the skin, it reduces the temperature and we feel cooler.

Their new invention is very effective in evaporating the sweat from the skin and then absorbing the moisture from sweat.

The main elements of this thin film are two hygroscopic chemicals, i.e. cobalt chloride and ethanolamine. In addition to being moisture-absorbent, this film also quickly releases water when it’s exposed to sunlight. And, it can be reused over 100 times!

On the other hand, conventional materials have a low water uptake and solid structures, making them unsuitable for absorption of moisture from sweat. Just for comparison, this new film takes in 15 times more moisture and does it six times faster than other materials.

And, it shows the absorption through a change of color, from blue to purple and then pink. It’s a great feature to use as an indicator of the level of moisture absorption. The scientists packaged the film into waterproof and breathable membranes that are flexible and common in clothing.

The Demonstration of the Absorption Was Successful

The scientists successfully showed the application of the moisture-absorbent film for shoe linings, underarm pads, and insoles for shoes. According to Ching, underarm sweating is embarrassing and frustrating for many and it also contributes to bacteria and worsens the body odor.

Moreover, shoe perspiration may increase the risk of calluses, blisters, and fungal infections. This is where the film could help with its moisture-absorbent properties. It dries and cools down the surroundings and provides comfort.

The team is hopeful that they’ll work with companies and include this film in consumer products.