Ultra-Dense Microsupercapacitors, as Thin as a Fingerprint, Could Power Future Wearables
Ultra-compact capacitors storing far more energy than previous efforts are being positioned as the next big — or small — thing in the IoT.
A team of researchers from the School of Energy and Chemical Engineering at UNIST in Korea have developed an ultra-compact microsupercapacitor that can be printed directly into circuits — and they're positioning it as ideal for the Internet of Things (IoT) and wearables.
"Microsupercapacitors (MSCs) have garnered considerable attention as a promising power source for microelectronics and miniaturized portable/wearable devices," the researchers note in the abstract to their paper. "However, their practical application has been hindered by the manufacturing complexity and dimensional limits."
"Here, we develop a new class of ultra-high areal number density solid-state MSCs (UHD SS–MSCs) on a chip via electrohydrodynamic (EHD) jet printing. This is, to the best of our knowledge, the first study to exploit EHD jet printing in the MSCs. The activated carbon-based electrode inks are EHD jet-printed, creating interdigitated electrodes with fine feature sizes. Subsequently, a drying-free, ultraviolet-cured solid-state gel electrolyte is introduced to ensure electrochemical isolation between the SS–MSCs, enabling dense SS–MSC integration with on-demand (in-series/in-parallel) cell connection on a chip."
"We were able to produce up to 54.9 unit cells per square centimetre (cm²) via electro-hydrodynamic jet printing technique," first author Kwonhyung Lee explains in a press release on the project, "and thus the output of 65.9 volts (V) was achieved in the same area. The on-chip UHD SS–MSCs presented here hold great promise as a new platform technology for miniaturized monolithic power sources with customized design and tunable electrochemical properties."
The prototype MSCs which came out of the study are extremely compact — roughly the width of a human fingerprint — and able to be printed during a chip's manufacturing process, giving it an internal power source. The team see the components as ideal for powering both wearable and embedded Internet of Things (IoT) devices.
The team's work has been published in the journal Science Advances under open-access terms.