Laser-Engineered Interfacial Dielectrophoresis-Aligned Nanowire Networks for Transparent Electromagnetic Interference-Shielding Films

Nanowires (NW) hold substantial promise for high-performance electronics; however, the lack of programmable, deterministic control and alignment strategies limits their seamless integration onto flexible target substrates, posing challenges to manufacturing reliability, efficiency, and scalability. Herein, we propose a scalable and adaptable interfacial dielectrophoresis (i-DEP) method for precise translational and rotational (0-150°) manipulation of NWs on thin polymer films. A subsequent noncontact picosecond laser post-treatment is introduced to effectively enhance electrical and optical properties by welding NW junctions through controlled thermal diffusion and localized-field confinement. The laser-welded silver nanowires (AgNW) network has attained ∼46× reduction in sheet resistance and a 10% enhancement in transmittance. The i-DEP aligned, laser-treated ultrathin AgNW/polyimide film achieves 35 dB electromagnetic interference shielding effectiveness, demonstrating over 1000× improvement compared to randomly oriented drop-cast AgNW networks. The additional shielding contribution arises from the capacitively coupled interwire network in the predefined aligned-NWs structure, realizing performance beyond that attainable by conductivity alone. This work presents a laser-engineered, i-DEP-aligned NW network that reinforces interfacial NW network quality and provides a systematic fabrication and optimization strategy for advancing wireless, flexible, and high-performance transparent electronic devices.