Dynamically cross-linked CL-20-based energetic films: A high-adhesion solution for PyroMEMS

Abstract

The development of miniaturized, flexible MEMS pyrotechnic devices necessitates advanced fabrication techniques. Herein, a strategy is reported that leverages the integration of ink-jet printing and dynamic cross-linking. The strategy successfully fabricates CL-20/PVA (polyvinyl alcohol)@PANI (polyaniline) energetic films with robust interfacial adhesion across heterogeneous structures. The PVA@PANI dynamic bonding system, designed through a molecular engineering strategy, provides dual interfacial enhancement characteristics. The 3D network structure formed by dynamic covalent cross-linking of borate ester bonds significantly enhances the flexibility of the system, as demonstrated by a 62.26% improvement in elastic recovery and a 55.26% increase in the plasticity index. Additionally, multiple hydrogen bonding interactions between hydroxyl groups and the substrate substantially improve interfacial adhesion, achieving a 4B rating on both glass and aluminum substrates. SEM characterization reveals a uniform and dense microstructure with homogeneously distributed crystals throughout the composite film. Performance testing confirms that CL-20 in the composite retains its ε-crystal form and exhibits a high detonation velocity of 7884 m/s. Furthermore, the synergistic incorporation of PANI reduces the electrostatic sensitivity by 10.86% compared to the CL-20/PVA baseline. The interfacial dynamic enhancement technology developed in this work represents a key advancement in the integrated structure–function design of microscale energetic devices, underscoring its strong potential for MEMS applications such as flexible micro-initiators and miniature solid propellants.