ARIS-J2-60048

Title Development of anisotropic thermally conducting and insulating substrates for recyclable flexible electronics
Area Engineering sciences and technologies: Chemical engineering, Production technologies Materials engineering: Chemistry, Materials, Paper, Textile, Electronic components and technologies
Presentation illustration
Duration 1. 1. 2025 – 31. 12. 2027
Funding 300.000 EUR
Sub-project head Prof. Dr. Vanja Kokol https://cris.cobiss.net/ecris/si/sl/researcher/8756
Participating organizations University of Ljubljana, Faculty of Mechanical Engineering https://www.fs.uni-lj.si/en/
Objectives In this project, we aim to develop a novel platform technology for the production of anisotropic thermally conducting and insulating flexible substrates using solution processed organic polymers (as cellulose, chitosan and PVA with good electrical/AC, DC and impulse breakdown strengths, moderate dielectric performance, and excellent volume resistivity) and highly thermally-conductive inorganic 2D insulators (as hBNs and hAlNs), thus to replace the most commonly used synthetic thermoplastics while enable to create a fully green and easy recyclable products to be used as a flexible substrate for electronics. This will be performed through their appropriate exfoliation and integration (dispersion, interactions) in CNF/biopolymer matrix using greener microwave/ultrasound assiste processes, and fabrication technology (alignment, density) using vacuum-assisted filtration and drying. Pre-designed nanocomposites will be used to study and optimize the production of self-standing thin-layer films (10-100 µm) or coatings (5-30 µm) applied on a flexible cellulose-based substrates (i.e. foil, paper or textile) by scalable slot-die coating technology. Such a manufactures substrates is expected to serve as a robust, el. isolating, dielectric, thermo-mechanically stable, flexible, and (in/through-plane) heat conducting substrates to be used in flexible electronic.
Specific phases and stage of realization
  • Determine how chemically/morphologically design and assemble the selected 2D nanosheets and celluose/PVA to control film thermal conductivity in prescribed directions..
  • Determine how to fabricate the thermally conducting film (using vacuum filtration) with good-enough flexibility, robustness, flatness/smoothness of its surface, minimal/controlled swelling, insolubility in water and organic solvent, good mechanical and thermal resistance.
  • Systematically control the parameters of films fabrication to understand the thermal transport mechanisms in newly designed substrates in terms of their morphology, charge, fibril/network structure and cellulose/PVA/2D fillers inter-chain coupling.
  • Utilize these data in developing and validating a numerical model by machine learning to optimize the design of nanocomposite substrates for better performance.
  • Develop up-scalable slot-die coating technologies combined with rapid near-infrared (NIR) irradiation drying, enabling precise (μm) and repeatable (±5%) production of nanohybrided self-standing films or coatings on a flexible substrate (foil, paper, textile).
Bibliographic references Articles
Scientific conference contributions
KOKOL, Vanja, VIVOD, Vera, KLINAR, Katja. Thermally conductive cellulose-based substrates for flexible electronics. V: LAVRIČ, Gregor (ur.), KAVČIČ, Urška (ur.). Proceedings of the 4th International Circular Packaging Conference : Ljubljana and online, 16th and 17th Oct.2025 : [4TH CPC 2025]. Ljubljana: Pulp and Paper Institute; Slovenj Gradec: Faculty of Polymer Technology, 2025. p. 84-89. https://icp-lj.si/international-circular-packaging-conference/?lang=en. V: KREŽE, Tatjana (ur.), FRAS ZEMLJIČ, Lidija (ur.), BRAČIČ, Matej (ur.). Engineering materials and process technologies : 2nd conference of programme groups of the Faculty of Mechanical Engineering University of Maribor : [29. 9. 2025, Maribor] : book of abstracts. 1st ed. Maribor: University of Maribor, 2025. p 22-23. DOI: 10.18690/um.fs.9.2025. 

KOKOL, Vanja, VIVOD, Vera, KLINAR, Katja. Thermal conductive properties of nanocellulose/hBN based substrates for flexible organic electronics. V: Graphene 2025 : June 25-28, 2025, San Sebastián (Spain). 2025. p. 1. https://www.grapheneconf.com/2025/posters.php