With printed electronics the two industries engineering and printing come together. Due to the developments in this sector we are able to print solar cells or flexible electronics. A recent invention might shake the world of printed electronics and take it one step further. The Korean battery scientist Sang-Young Lee from Ulsan National Institute and Technology (UNIST) in South Korea has now turned a normal inkjet printer into a machine that prints electronic circuits and supercapacitors (energy storing devices).

A simple but yet effective recipe for electric circuits

For the past five years Lee and his team have worked on the flexible batteries. The architecture of a battery has not changed since its invention back in the day. Therefore the scientists can transfer the concept on the production of the new batteries. This might revolutionize the way we use our electronic devices: Flexible batteries will disappear into a design instead of having a pouch or battery box. What is so special about it is that the new batteries can be made using a simple inkjet printer.

The process is fairly easy: First the ink cartridges of the printer have to be emptied in order to refill them with conductive electrolyte inks (invented by Lee and his team) and special battery material. After that the inkjet printer will be filled with paper which has been treated with a cellulose primer. This is necessary because on normal paper the ink would dissolve. After the first layer has been brought onto the paper the printing of the actual battery begins: “We use carbon nanotubes, which replace the foil current collector in a battery, and silver nanowire electrodes, followed by [the] electrolyte ink”, says inventor Lee.

Super caps printing for everyone

In contrast to other processes for printing flexible electronics and super caps, Lee’s solution works with a normal inkjet printer which can be found in every household. Other projects still needed liquid electrolytes that had to be added after the printing and an extra pouch to hold the electrolytes was necessary as well. The new idea presented by Lee and his team however can print the whole ‘battery’ on the paper.

The scientists demonstrated their invention in the form of a cup sleeve where a super cap has been printed on. This cap provides a blue and a red LED with power which lighten up according to the temperature of the cup’s content. In a next step Lee wants to increase the capacities of the batteries and develops solutions for printing on different materials.

What do you think, are printed batteries essential for the forthcoming of the Internet of Things? Leave us your opinion in the comment section.