Scientists from Germany have developed, according to them, the smallest supercapacitor with a voltage like an AAA battery.
The authors of the new study worked in the field of nano-supercapacitors (nBSC): these are the same conventional capacitors, but they are scaled down to a submillimeter scale.
It is quite difficult to develop such a device, moreover, the developers tried to make it safe for the human body in order to power the tiny sensors and implants.
Typically, such biosupercapacitors have a size of about 3 mm³, but the authors of the new work have made the limiting size even smaller. The design of the new supercapacitor is based on a set of polymer layers that are bonded together with a photosensitive photoresist material: it acts as a current collector. Separating membrane and electrodes made of an electrically conductive biocompatible polymer called PEDOT: PSS.
This set of layers is placed on a thin surface under high mechanical tension in order to separate some of the layers and fold them literally in the origami style into a 0.001 mm³ nanobiosupercapacitor. It takes up less space than a grain of dust.
As a result, the new biosupercapacitor turned out to be 3 thousand times smaller than the previously developed analogs.
The device was then placed in turn in saline, blood plasma and blood to test its operation. As a result, the supercapacitor continued to store energy. It proved to be particularly effective in blood and was able to retain 70% of its capacity after 16 hours of operation.