Advanced Manufacturing of Functional Lightweight Conductive Composite Systems for Sustainable and Flexible Electronics

Electromagnetic interference (EMI) is generated by various undesirable signals, predominantly emitted by electronic devices. Substantial research indicates that prolonged exposure to such EMI emissions may negatively affect human health and compromise the operational efficiency of electronic equipment. Consequently, the development of materials for effective EMI shielding has gained significant importance.Conductive polymer composites (CPCs) offer promising potential as advanced materials for EMI shielding applications. CPCs are lightweight, easily processed, and exhibit favorable mechanical and thermal characteristics. Typically, polymers are naturally insulative; however, by incorporating nanoscale conductive fillers such as graphene, carbon nanotubes (CNT), and MXene, these nanocomposites achieve the necessary electrical conductivity for EMI shielding. Polymer foams and aerogels, categorized as lightweight CPCs, are widely utilized in applications including thermal insulation, impact absorption, acoustic materials, and packaging, due to their enhanced mechanical resilience, impact strength, and toughness. Furthermore, micro- or nano-cellular structures within these materials can significantly improve electrical conductivity and EMI shielding effectiveness, making CPCs integral to advanced applications such as energy storage devises, capacitors, supercapacitors and triboelectric nanogenerators (TENGs) and fuel cells. This research emphasizes the need to explore the influence of intense flow fields encountered during CPC fabrication, particularly in advanced manufacturing processes, on the materials' electrical and EMI shielding properties. Additive manufacturing, specifically 3D printing, provides a cutting-edge method for producing CPCs with controlled cellular architectures. This dissertation investigates the uniaxial orientation of CPCs above the glass transition temperature (Tg) followed by foaming. The study also explores the production of CPCs using both in situ foam 3D-printing and aerogel 3D-printing methods. Findings indicate that 3D-printed CPCs exhibit enhanced electrical and thermal conductivities, EMI shielding, energy harvesting capabilities, and mechanical durability. The study underscores 3D-printing techniques, notably foam and aerogel 3D printing, as versatile, efficient approaches to producing CPCs with tailored properties. This research deepens the comprehension of structure-property interdependencies, enabling the precise engineering of CPCs for specialized roles in thermal management, EMI shielding, energy storage, and energy harvesting applications.

Department dc:contributor.department

Mechanical and Industrial Engineering

Year dc:date.issued

2025

Author dc:creator

• Jalali, Amirjalal

Advisors dc:contributor.advisor

• Park, Chul
• Sain, Mohini

Handle dc:identifier.uri

https://hdl.handle.net/1807/150126

OAI identifier oai:identifier

oai:utoronto.scholaris.ca:1807/150126