<scp>3D</scp>‐Printable Polymer Composites With Unmodified Boron Nitride for Thermal Management in Flexible Electronics

ABSTRACT Flexible high‐performance electronics are facing the challenge of managing increasing thermal loads in the latest devices. This study presents a one‐step method for 3D printing flexible boron nitride (BN) polymer composites via vat photopolymerization, enhancing thermal conductivity by 270% to 0.8 W m −1 K −1 and improving dielectric properties (17% lower permittivity and 18% reduced dielectric loss). Unmodified h‐BN microplatelets are integrated in a UV‐curable polymer matrix, simplifying the manufacturing compared to functionalized or hybrid filler systems. Composites with 20 wt% BN achieve feature resolutions of 125 μm with excellent dimensional fidelity, while mechanical properties show an increase in tensile strength of 215% and retain flexibility. The thermal performance of the 3D‐printed structures is assessed using IR thermography under simulated operational conditions, confirming enhanced heat transfer in the BN‐filled structures. Overall, this research presents a practical method for improving thermal management in flexible electronics, offering an easy way to create high‐resolution 3D‐printed polymer composites. The resulting materials strike an optimal balance between thermal conductivity, dielectric properties, and mechanical flexibility, making them perfect for applications that demand exceptional thermal control and mechanical performance, such as artificial intelligence (AI)‐driven systems and flexible wearable technologies.