This Microbattery Is the Size of a Speck of Dust

Contemporary technological breakthroughs range between macrostructures the size of the CERN particle accelerator, which has given us discoveries of elusive particles such as the Higgs boson, and feats of miniaturization such as this camera the size of a grain of salt that we talked about recently.

And while microchip production has long since settled on nanometer scales, the tiny batteries that will power the microcomputers of the future are not yet up to scratch. And that's what a new origami-like foldable battery is coming to change. It is the size of a speck of dust and could power microscopic devices circulating in our veins.

A battery that can be rolled up like a roller shutter

The most common approach in battery manufacturing is "wet chemistry", i.e., chemical solutions that conduct electric current. The problem is that, as we move into the microscopic realm, the use of liquids becomes unfeasible. Until now, photovoltaic cells or ultrasonic power generation have been used. However, researchers at the Chemnitz University of Technology in Germany have adopted another approach to create a 0.04 mm² microbattery.

This innovative prototype uses two microchip layers on which a positive and a negative solid electrode film has been printed. Between the two layers they have placed a solid electrolyte with conductive properties. However, the surface area useful for generating electricity is very small. This is where the other element of the equation comes in.

The substances deposited on these extremely thin sheets tend to roll up spontaneously thanks to micro-origami techniques. The result is a cylindrically rolled-up shutter structure that multiplies the energy-generating surface area. This is a technique similar to that of the latest-generation cylindrical batteries in Tesla's electric cars.

The next challenge: integrating microprocessors

Of course, no one should expect nuclear fusion reactor figures at these scales. The researchers believe that the battery technology, which uses the type of foils present in microchips, lends itself to integrating microprocessors on the same scale.

The nanobattery, which is rechargeable, could power today's most miniature microprocessors for ten hours to perform essential functions. For microprocessors that monitor and transmit information, batteries with higher energy density would be required.

For now, it is a prototype that has not yet reached the production stage. Still, its creators estimate that it could be manufactured at a reduced cost once the process has been fine-tuned. They believe that it could be the first step towards a new generation of high-power microbatteries.

Alternative batteries: from paper to wireless power

Besides extreme miniaturization, other battery technologies have surprised us recently. One example would be printing batteries on paper that are activated by moisture. These devices are flexible and biodegradable. In fact, by relying on electricity-generating bacteria, once the battery is exhausted, the microorganisms metabolize the medium until it disappears.   

Another innovative battery incorporates wireless charging technology, specifically using the same radio frequency spectrum as Bluetooth.    

Finally, one of the most striking batteries in terms of circular economy is the technology based on eggshells that we address in this article. Researchers have taken advantage of the calcite present in this organic material for their new battery proposal. This is the first time that organic waste has been used to produce an electrode.

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Sources:

• Science Alert
• https://resourceworld.com/jelly-roll-layer-cake-or-popsicle-stick-the-evolution-of-lithium-ion-battery-shapes-in-evs/