Cold, Rapid, and Scalable Stamping of Aramid‐Networked Viscoelastic h‐BN Doughs for Complex Thermal Architectures

Abstract

ABSTRACT Extensive efforts have been made to fabricate complex 3D thermal management materials from hexagonal boron nitride (h‐BN) using 3D printing and templating. However, these techniques are often energy‐intensive, time‐consuming, and inherently limited in scalability, owing to prolonged processing times and low throughput. Herein, we report a cold, rapid, and scalable stamping approach for constructing intricate, large‐area h‐BN‐based thermal architectures. This strategy relies on forming highly viscoelastic h‐BN doughs achieved through developing a para‐aramid ( p ‐aramid) fiber network and densification via a bimodal alumina mixture. The p ‐aramid network maximizes viscoelasticity with a minimal binder content (5.1 wt.%), enabling the doughs to exhibit pronounced plasticity during stamping while maintaining solid‐like behavior after relaxation. Consequently, the doughs conform precisely to complex stamp geometries within 2 s under ambient conditions, preserving their high structural integrity. Scalability is demonstrated by stamping various 3D geometries exceeding 10 cm, including cubes, cylinders, annular sectors, and honeycombs. Furthermore, the fiber‐reinforced structures exhibit enhanced thermal conductivity (TC) and fatigue resistance under extreme temperatures (− 50°C and 200°C). Notably, the resulting architectures substantially improve the TC of the polymer composites when used as internal frameworks. This low‐energy stamping strategy represents a paradigm shift in the processing of advanced thermal materials.