A research team at The Hong Kong Polytechnic University (PolyU) has developed "IntraSpect™", a third-generation intelligent in-situ laser melt pool monitoring technology that marks a breakthrough in high-end precision manufacturing. During welding, high-energy heat sources melt metal to form a micro-scale molten zone known as the melt pool. Its internal condition directly affects welding quality, yet conventional technologies are unable to monitor it in real time during processing. By combining Optical Coherence Tomography with a multi-modal artificial intelligence engine, IntraSpect™ creates an "Industrial Eye" capable of monitoring the melt pool's internal condition in real time with micron-level precision, capturing three-dimensional morphological changes during welding to address the long-standing industry challenge of welding defects at source. The project has established partnerships with multiple industry leaders in the Greater Bay Area and is advancing commercialisation, with potential applications extending to medical devices, aviation, aerospace and other sectors demanding exceptionally high welding quality.
The IntraSpect™ project is led by Prof. H.C. MAN, Dean of the Faculty of Engineering, Cheng Yick-chi Chair Professor in Manufacturing Engineering and Chair Professor of Materials Engineering; and Prof. Xiewen WEN, Assistant Professor of the Department of Industrial and Systems Engineering. Prof. Man has devoted forty years to the field of high-power laser welding, accumulating extensive industry collaboration experience and a deep understanding of industry pain points and practical needs. Prof. Wen specialises in precision optical instrument design and micro-scale dynamic capture technology. Their interdisciplinary collaboration and complementary expertise have ensured that the development of IntraSpect™ has been closely aligned with industrial application scenarios from inception.
Prof. H.C. Man said, "Conventional welding monitoring relies primarily on surface observation or post-process inspection, making it difficult to capture the melt pool's internal condition in real time during processing. The consequences range from product scrapping and economic losses to, at worst, safety incidents. IntraSpect™ intervenes at the source, identifying and correcting defects at an early stage. This transforms reactive post-process inspection into proactive prevention, dramatically reducing scrap rates while significantly enhancing production efficiency and product reliability."
Prof. Xiewen Wen explained, "IntraSpect™ is like equipping welding machinery with an 'Industrial Eye'. Within one-millionth of a second, it can penetrate the arc flash, metal vapour and spatter generated during welding to directly measure the three-dimensional depth and morphology inside the melt pool, achieving micron-level, real-time navigation. This enables the machine to self-correct during welding, achieving closed-loop process control."
Testing has validated that the IntraSpect™ system's detection data deviates by less than two percent from destructive testing results, with technical specifications reaching internationally leading standards. Compared to similar imported products, the system costs approximately half as much, with investment recoverable in less than one year. The team estimates that this technology can replace up to 70% of destructive testing processes, substantially saving material and time costs while achieving 100% comprehensive monitoring and establishing a complete quality traceability record for every weld.
IntraSpect™ will initially focus on precision welding processes for new energy vehicle batteries and 3C electronic products such as smartphones. The team is collaborating with industry partners on pilot testing to transform the technology into practical industrial solutions. In the long term, the technology has additional potential for extension to medical devices, aviation, aerospace and other sectors with extremely stringent welding quality requirements.
Prof. Christopher CHAO, Senior Vice President (Research and Innovation) of PolyU, remarked, "IntraSpect™ fully demonstrates PolyU's unique strengths and potential in deep industry-academia-research integration. We are committed not only to achieving original breakthroughs in frontier technologies, but also to translating research outcomes from campus to industry for the benefit of society. The National 15th Five-Year Plan continues to emphasise the development of new quality productive forces, and intelligent manufacturing is the core engine driving industrial upgrading through technological innovation. PolyU will continue to actively align with national strategies and the HKSAR Government's new industrialisation policies, contributing to the upgrading of high-end manufacturing in the Guangdong-Hong Kong-Macao Greater Bay Area and further consolidating Hong Kong's unique position as an international innovation and technology hub."
The team aspires to combine Hong Kong's research strengths with the Greater Bay Area's industrial ecosystem to build a safer, more efficient and more intelligent high-end manufacturing system for the Nation, while injecting new momentum into Hong Kong's high-quality economic development.
