Jenny Wiklund: Acetylated cellulose nanofiber films: Durability and functionality in printed electronics

Abstract: 

The increasing consumption of electronic devices and the depletion of non-renewable resources have created a demand for more sustainable materials in the electronics industry. By printing electronically conductive ink patterns, waste can be reduced and the use of non-renewable materials can be decreased, compared with traditional manufacturing methods. However, improving sustainability further requires biobased materials that can replace fossil-based plastic substrates as a base in printed electronics.

This doctoral dissertation investigates acetylated cellulose nanofiber (ACNF) films as an environmentally friendly alternative to conventional plastic substrates used in printed electronics.

The suitability of ACNF films as substrates was examined by analyzing their surface properties and interactions with a silver nanoparticle (AgNP) ink. The results were compared with the results of cellulose nanofiber (CNF) and poly(ethylene terephthalate) (PET) reference substrates. The findings showed that ACNF substrates provided good print quality and electrical functionality, as well as superior ink adhesion and lower ink spreading of the inkjet printed AgNP ink pattern compared to those on the PET substrates.

The long-term durability of the materials was investigated through artificial ultraviolet (UV) induced photodegradation treatment. The ACNF films showed no significant deterioration in optical, mechanical, or electrical properties compared with the reference substrates.

As a practical demonstration, an antenna was printed on ACNF films using aerosol jet printing. The electrical performance of the antennas on ACNF substrates was comparable to that of the antenna on PET substrate. While the antenna on the PET substrate degraded during photodegradation, the antennas on the ACNF substrates maintained their properties considerably better.

The dissertation demonstrates that ACNF films are a promising and sustainable alternative to conventional plastic films in printed electronics.

Opponent: Prof. Julien Bras, INP Grenoble, France

Custos: Prof. Jouni Paltakari, Aalto University School of Chemical Engineering

Link to electronic thesis: LINK