H2020 INNPAPER Project: Innovative and intelligent printed electronics based on multifunctional paper: from smart labeling to point-of-care bioplatforms

During the second period (M13-M30), the main results achieved are the following:

Papers with tailored conductivity, hydrophobicity, and porosity were tailored to the application scenarios. A nanocellulose/carbon nanotube ink was shown to be an ideal material for the humidity sensor. Transparent cellulose films with tailored microstructure and hydrophobicity were tested as a potential cover layer for electrochromic displays.

For use case 2 (PoC immunosensors), printable fluidic channels were developed using nanocellulose-based inks, and tailor-made bioreactive papers with enhanced affinity of paper-based fluidic channels to proteins and antibodies were also fabricated. The SUTCO line for nanopaper production and the subsequent embossing line using roll-to-roll nanoimprinting, as well as the plasma line for nanopaper hydrophobization, were established. In addition, MNFC production was scaled up. The quality of MNCF was improved, and production capacities of 200 and 5000 kg were achieved for pilot and industrial scales, respectively.

Regarding the devices, cellulose electrolytes for printed batteries and electrochromic displays were formulated following two approaches: 1) Generation of viscous electrolytes with high solids content; 2) Self-supporting hydrogel electrolytes formed with crosslinking agents. Both the functional coplanar zinc-carbon printed batteries and electrochromic displays based on cellulose electrolytes were successfully produced on Powercoat paper.

The communication system for interconnecting the sensors to a memory and exchanging data with the phone was also developed and tested in real-world settings.

For use case 1 (smart labels), printed environmental devices are required: a temperature sensor was developed for measurements between -10°C and +60°C, with very stable results between -10°C and +20°C. Humidity sensors were also developed with a good correlation between humidity variation and the captured current. The first paper-based pressure sensors were also tested, with good response.
For use case 2 (PoC immunosensors), different strategies are being pursued. One of the most innovative approaches is the one involving a printed cellulose-based porous channel, mentioned above. The results obtained are promising, but the integration of electrochemical detection is not yet complete.

Finally, for Use Case 3 (PoC genosensors), work during this period focused on developing new capabilities for paper-based microfluidics and improving paper-based electrochemical sensing.

For the manufacturing of the common platform and the three use cases, the final design was completed. A debugging test PCB was developed to test both elements. Two electronic platforms were designed and manufactured (one for use cases 1 and 3, and another for use case 2). A free smartphone app for data collection, visualization, and cloud storage was successfully tested.

The first manufacturing tests of the common paper platform using screen printing were successfully completed following the following process flow: 1) printing of the conductive traces, antenna, and connection pads; 2) printing of the display; 3) printing of the battery. The functionality of the different devices has been verified. The next steps are the selection and placement of the silicon components and their characterization.

The communication strategy has focused on community development and stakeholder engagement through the newsletter, social media, press office activities, and event communication. An open call for new ideas has been launched ( https://innpaper.eu/open-call/ ). Four scientific articles have already been published in peer-reviewed scientific journals, and two more have been submitted. In addition, four patent applications have been generated.