While wearable tech is making many things possible regarding collecting biometric data, there is still one unifying thing holding wearables back: they’re still attached to the wall socket because they need to be charged. But what if wearables were no longer linked to the wall socket? A report has surfaced that Chinese scientists are researching stretchy fibers that could one day be woven into clothing to power wearables.
Researchers at Fudan University in Shanghai are suggesting that these fibers could mimic electric eels. “It takes a page from nature to solve real-world problems and even surmount nature in some aspects,” said Hao Sun, the study’s lead author and a materials scientist at the university. Schematics show the fibers combine carbon nanotubes with insulating rubber wires and electrolyte gel to create capacitors. Capacitors alternate pairs of electrical conductors (which allows the flow of electrical energy) and insulators (which block the flow of electrical energy). These capacitors would then store electric charges on the surfaces of the conductors. Capacitors have a huge advantage over batteries: they can capture and release energy a lot faster than batteries can. However, their storage capabilities are still less than that of a battery.
This technology parallels the anatomy of the electric eel, which has cells known as electrocytes. These cells store and release electrically charged ions to generate powerful electric fields as a defense mechanism against predators. The electric eel also uses this to hunt prey. By themselves, electrocytes have a voltage of 0.15 volts, but an electric eel has thousands of electrocytes that can allow it to produce shocks of 600 volts (by comparison, wall sockets in the United States are only a fifth of that).
The materials used by the researchers at Fudan University were reported to generate around 1,000 volts from a single fiber about 12 meters (39 feet) long, almost ten times as much as a wall socket. This could allow wearables to charge more quickly. In addition, these fibers could stretch 70 percent more than their usual length without losing any of their electrical or structural properties. One test subject included a T-shirt that powered 57 LED lights.
How do they plan to keep wearables charged? One can look to solar energy to play a main role in getting wearables off the wall socket. Fiber-shaped solar cells could be used in conjunction with these electric eel fibers to both store energy and harvest their use in wearable devices. “These energy fibers might be incorporated into our daily clothes to power our wearable devices such as the Apple Watch and Google Glass,” Sun said.
One article from The Verge claimed that battery life in wearables was not only still too low, but that it was also the most difficult part of the technology to advance. “Battery life is the hardest piece of technology to advance. I think every year there’s been a few-percentage increase in power density in lithium ion cells, but you can’t bank on the fact that there will be a huge step forward in battery chemistry or battery technology,” said Fitbit co-founder and CEO James Park during an interview at the 2016 Consumer Electronics Show (CES).
“We think these findings provide an efficient strategy for the advancement of flexible electronics and wearable devices,” Sun said. A key part of wearables is its ability to gather data for long periods of time, and extending the battery life will help wearable tech manufacturers reach that goal.