Recyclable paper‐based electronics
The CircEl-Paper project is developing paper-based electronics with high integration density to replace conventional printed circuit boards, facilitate recycling and increase the return rate of electronic products. To achieve this, the project will build on the circular economy for paper products accepted by consumers, into which the recycling loop for paper-based electronics will be integrated.
To this end, the conventional, poorly recyclable printed circuit boards made of fiber-reinforced plastics used in electronic devices are to be replaced by paper-based ones. New manufacturing processes can ensure a high integration density. Used paper-based PCBs should then simply be fed into a paper recycling process to separate and recover the electronic components, metals and functional materials. The use of renewable raw materials is also expected to reduce the carbon footprint - by up to 60% CO2 equivalent compared to conventional PCBs could be achieved.
CircEl-Paper will demonstrate the feasibility and evaluate the environmental footprint based on three specific use cases:
1. medical sensors to measure glucose levels on the surface of the skin
2. packaging with time-temperature indicator (TTI) labels
3. acoustic greeting cards with music
The fact that the changeover will be essential in electronics production is clear from the global figures. According to the "Global e-waste monitor 2020" published by the ITU (United Nations specialized agency for information and communication technologies), more than 53 million tons of e-waste were produced in 2019 [1], and the trend is rising - a new report has been announced for 2023. But only 17 percent was properly collected and recycled worldwide. A large amount of valuable materials produced at great expense is thus regularly lost. That's because nearly all of these electronic products incorporate electronic printed circuit boards (PCBs) that contain sensors, chips, capacitors, resistors and other electronic components. The PCBs themselves consist of a pre-impregnated, fiber-reinforced plastic and copper-based circuitry. Metals such as Pd, Ag, Ni, Au, etc. and additional polymers (solder masks, dielectrics, etc.) are also involved.
The scientific team develops special hybrid polymers (ORMOCER®), which can be used as interlayer dielectrics, encapsulating or insulating materials for printed capacitors and can be synthesized from biobased raw materials. Furthermore, alternative electrically conductive inks are being developed, consisting of already recycled and available raw materials, and are free from silver particles, which have a negative environmental impact due to their antibacterial properties. The developments aim to further reduce the ecological footprint of paper-based electronics.
[1] https://www.itu.int/en/ITU-D/Environment/Pages/Spotlight/Global-Ewaste-Monitor-2020.aspx