Dissertation Defence: Electrically Conductive Electrospun Nanofiber Mats for Electromagnetic Intereference (EMI) Shielding Applications
March 30 at 10:00 am - 2:00 pm
Navid Keshmiri, supervised by Drs. Mohammad Arjmand and Abbas Milani, will defend their dissertation titled “Electrically Conductive Electrospun Nanofiber Mats for Electromagnetic Interference (EMI) Shielding Applications” in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Mechanical Engineering.
An abstract for Navid Keshmiri’s dissertation is included below.
Examinations are open to all members of the campus community as well as the general public. This examination will be offered in a hybrid format. Registration is not required to attend in person; however, please email mohammad.arjmand@ubc.ca to receive the Zoom link for this exam.
Abstract
The rapid proliferation of electronic devices and wireless communication systems has heightened concerns about electromagnetic interference (EMI), driving demand for lightweight, flexible, and durable shielding materials suitable for wearable and outdoor applications. This thesis investigates the development of electrically conductive electrospun nanofiber mats as multifunctional EMI shielding platforms by integrating materials design, processing optimization, and functional performance evaluation. The work is structured around four interconnected research streams. First, electrospinning parameters and polymer selection were systematically optimized to fabricate mechanically robust and stretchable polyurethane (PU) nanofiber substrates with uniform morphology and enhanced durability. Second, a vacuum-assisted assembly strategy was developed to impregnate PEDOT:PSS into the porous nanofiber scaffold, producing strong interfacial bonding and significantly improving electrical conductivity and EMI shielding effectiveness. Third, a synergistic hybrid architecture combining silver nanowires (AgNWs) with PEDOT:PSS was engineered to minimize conductive material consumption while maintaining high performance. The optimized PU-AgNW-PEDOT:PSS textile exhibited high EMI shielding performance at an ultrathin thickness, while maintaining excellent mechanical resilience, stable performance under repeated cyclic deformation, and strong elastic recovery. Finally, multifunctionality was introduced to enable outdoor applicability and energy harvesting. A durable superhydrophobic coating was achieved using a PDMS/nanosilica formulation, yielding water contact angles up to 150.7° and strong resistance to tape peeling and harsh chemical environments. In parallel, the conductive textile was demonstrated as an effective positive triboelectric layer in a triboelectric nanogenerator (TENG), generating high electrical outputs and sufficient power to drive commercial light-emitting diodes.
Collectively, this thesis establishes a scalable materials and processing framework for next-generation porous fiber-based conductive textiles that combine mechanical durability, high EMI shielding efficiency, environmental robustness, and self-powered energy harvesting, offering strong potential for deployment in wearable electronics, defence, and smart textile technologies.
