A new era of paper products has dawned. Multifunctional products for sustainable electronics can be produced under safe conditions and at a low cost. Making paper semi-conductive is one such project that we have recently worked on at Innventia. This was a pioneering experiment in which low-tech became high-tech, thanks to zinc oxide.
We live in a world where more and more products are becoming connected, and the increase in connectivity is faster than ever. And while electronics need to become smarter, there is also an obvious need for sustainable development – ideally at a low cost.
At the beginning of the year we were involved in a big step towards this new era. Our researchers and engineers had spent almost an entire year planning an experiment that was ready to be completed.
Our vision was to manufacture a new multi-material in a paper machine. A material that can be used as an active component in electronic applications, such as solar cells and electrical circuits. It should also be produced at a low cost.
We can now unveil the result: semi-conductive paper! Paper that is active instead of passive, and that offers opportunities for many new and exciting products.
The main components we used were paper pulp and a special variant of zinc oxide. Zinc oxide is most commonly used in sunscreen and biomedical applications. But here we used a different structure that can generate an electric signal.
When paper containing zinc oxide is exposed to UV light, is becomes conductive. This means that the paper’s electronic properties are interactive and can be controlled using a UV lamp. The paper can then be integrated with electronics for various components, such as solar cells or sensors.
The test run took place in January 2015, using the FEX machine at Innventia’s pilot facility. There, we produced almost a tonne of semi-conductive paper together with Acreo Swedish ICT, our partner for this ground-breaking experiment.
The trial shows that paper can be given high-tech functionality, even though it is usually regarded as a low-tech material. Our vision has thus become reality. And this is what is so exciting – carrying out research and achieving results that go above and beyond traditional papermaking.
High-tech materials must, of course, be treated with respect and knowledge. Hence the protective equipment shown in the images. But it’s not as dramatic as it looks. When carrying out non-traditional research, there aren’t always regulations in place. Our assessment was therefore that we could handle the material, but that we should avoid exposure to dust – which was important in this experiment. Safety is always our top priority, so we take a ‘belt and braces’ approach when working with what drives us: constant curiosity about what lies around the corner.
“The biggest challenge during the trial was to get the zinc oxide to adhere without any waste,” explains Dina Dedic, who was responsible for the run. “Resource planning and environmental awareness are always top of mind, whatever we do. We were therefore keen to minimise waste.”
The interesting thing about this trial is the future opportunities. We now have a multi-material that can be used for applications like light and moisture sensors or energy generation – in solar cells, for instance. There are also many other possibilities.
Project manager Hjalmar Granberg explains:
“For the first time ever, we’ve devised real paper electronics: paper in which the electronics are part of the paper itself and not just printed on it. And the fact that it’s produced at a low cost opens up all manner of opportunities! The next step will be to investigate how production can be simplified and further converted into various devices. But for now we can safely say that we’ve performed a break-through trial without any break-downs!”
» Presentation about how to make paper into an active substrate for large area electronics.