Roadmap for the Industrialization of Robotic Continuous Ultrasonic Welding of Fiber-Reinforced High-Performance Polymers in the Aerospace Industry

The aerospace sector is progressively integrating fiber-reinforced high-performance polymers, due to their superior strength-to-weight ratio, corrosion resistance, and design flexibility. Conventional joining methods, such as mechanical fastening or adhesive bonding are labor-intensive, defect-prone, and costly, therefore limiting manufacturing efficiency. Ultrasonic Welding (UW) of thermoplastic composites has emerged as a rapid, adhesive-free joining technique that employs high-frequency vibrations to produce robust and high strength bonds. UW enables the assembly of complex geometries while minimizing weight, material waste, and processing time, thereby enhancing design freedom and structural integrity. In aerospace, UW facilitates the fabrication of lightweight, high-performance structures that comply with stringent safety and regulatory standards, eliminates drilling and riveting-induced damage, and supports innovative architectures previously unfeasible. This review summarizes the principles of static and continuous UW, highlights its advantages, and surveys current aerospace applications, with emphasis on the different development milestones. A roadmap towards industrial maturity is outlined, calling for coordinated efforts among industry, academia, and regulatory bodies to standardize processes, certification, and qualification of UW joints. Advancing UW to full commercial readiness promises to transform airframe manufacturing, unlocking the widespread adoption of this technology for next-generation aircraft.