In the not so distant future, imagine how a brand-new smartphone model will be released. Consumers wishing to buy one will simply take the electrical ink off the shelf, turn on their computer and click ‘print’. A few minutes later, the printer will spew out this latest model. The ink that will be used as an input will be specially designed for printed electronics and capable of creating circuits for any electronic device.

The Organic Printed Electronics Laboratory (OPEL) headed by professor Yong-Young Noh at the Department of Chemical Engineering, POSTECH, is developing printed electronic materials that serve as the functional ink to ‘print out’ electronic devices. This essentially involves the development of a wide array of electronic materials required for the manufacturing of such devices in ink-like printable solution formats. As all that is needed is a small printer, printed electronics technology is expected to enable virtually anyone to affordably produce electronic devices themselves.

This promising technology, however, faces the daunting challenge of creating solution-based inks. In particular, silicon, the semiconducting material that is most widely used across diverse industries, can hardly exist in solution formats. Meanwhile, different industries are embracing printed electronics technology to gradually generate noteworthy accomplishments: quantum dot light-emitting diode (QLED) displays are manufactured through the solution-based process that uses solutions containing quantum dots, and diagnostic kits can be produced at affordable prices through printed electronics in the pharmaceutical industry.

Armed with a range of printing equipment, from inkjet printers to three-dimensional printers, the research team is generating never-before-possible outcomes. For instance, the Lab succeeded in sorting and dissolving high purity semiconducting  carbon nanotubes, which are known for their very poor water solubility, and developing fabric-based gas sensors through the printing of these highly insoluble materials. This achievement earned professor Noh the Scientist of the Month Award granted by the Ministry of Science, ICT and Future Planning. Recently, the Lab published an article on its development of copper-iodide transparent p-type semiconductors and invisible integrated circuits at the international journal of ‘Nature Communications’.

Researchers at the Lab firmly believe that it will be possible someday to directly manufacture simple devices through the use of printing. Just as we print out paper documents, we will purchase ink and use this ink to print out electronic devices. When compared to today’s costly manufacturing processes, low-priced printing technology will enable businesses to establish price competitiveness. Professor Noh’s research team ultimately forecasts that as this technology matures further, it will usher in an era where rollable smartphones are simply printed out like newspapers to be displayed at shops for sale.