Biodegradable Polylactic Acid Emulsion Ink Based On Carbon Nanotubes And Silver For Printed Pressure Sensors

The research, conducted by Maedeh Najafi and co-authors at the Istituto Italiano di Tecnologia, investigates the development and application of biodegradable and conductive inks for printed electronics. The study aims to create environmentally sustainable electronic materials that address sustainability challenges in electronics manufacturing. Specifically, the researchers developed a biodegradable ink by incorporating silver flakes and multi-walled carbon nanotubes (CNTs) into a polylactic acid (PLA) and polyurethane dispersion matrix. This ink was subsequently used to fabricate flexible pressure sensors, highlighting the potential for eco-friendly electronic devices.

1. Biodegradable Conductive Ink:

• The ink developed uses a combination of PLA, a biopolymer, and PUDs to enhance flexibility and biodegradability.

• Conductive fillers include silver flakes and CNTs, which provide the necessary electrical properties while maintaining eco-friendliness.

2. Voltera V-One PCB Printer:

• The Voltera V-One PCB printer was instrumental in the research, used to create eight-finger interdigital electrodes on a polydimethylsiloxane (PDMS) substrate.

• This printer enabled precise and efficient patterning of the conductive ink, crucial for the sensor's performance.

3. Sensor Fabrication and Performance:

• The sensors demonstrated high sensitivity and stable performance over a pressure range of 0.2 to 500 kPa.

• The study found a consistent relationship between applied stress and changes in electrical resistance, validating the ink's effectiveness for pressure sensing applications.

4. Environmental Impact:

• The ink's biodegradability in marine environments was tested, showing significant degradation over time, which helps prevent environmental accumulation.

• The study emphasizes the importance of developing materials that align with green principles and circular economy concepts.

The Voltera V-One PCB printer played a critical role in the successful fabrication of the sensors. Its ability to print precise patterns using the biodegradable ink was crucial in demonstrating the practical viability of the research. The employment of this printer underscores the significance of advanced printing technologies in the development of next-generation, environmentally-friendly electronic devices.

Credit to the original authors: Najafi, M., Forestier, E., Safarpour, M., Ceseracciu, L., Zych, A., Bagheri, A., Bertolacci, L., Athanassiou, A., & Bayer, I. (2024). Biodegradable polylactic acid emulsion ink based on carbon nanotubes and silver for printed pressure sensors. Scientific Reports, 14, 10988. https://doi.org/10.1038/s41598-024-60315-z.