Enhancing the Adhesion Strength of Polymer-Based Joints via Atomic Layer Deposition Surface Modifications

Enhancing the adhesion strength of polymer-based components is a critical challenge in advancing their use as structural and functional materials. Atomic layer deposition (ALD) offers a novel approach to address this challenge by enabling precise surface modifications that improve the adhesion performance. This work studies ALD-based surface modification of 3D-printed acrylonitrile butadiene styrene (ABS)-like single lap shear joints and investigates their adhesion performance. By depositing Al₂O₃, TiO₂, and ZnO layers, we demonstrate significant improvements in shear strength, strain at failure, and toughness. Surface characterizations revealed that these enhancements stem from both chemical and physical modifications, including increased surface energy and the formation of wrinkled patterns that can facilitate mechanical interlocking. Different growth mechanisms led to the formation of distinct wrinkled and crease patterns; while Al₂O₃ and TiO₂ grew on the polymer's surface, ZnO grew within the ABS-like substrate via vapor phase infiltration (VPI). The surface morphologies and mechanical responses varied depending on the oxide type and number of ALD cycles. This work underscores the potential of ALD as a versatile surface treatment for improving adhesion performance in polymer-based materials and advancing bonding strategies for high-performance applications.