Honoring Emeritus Professor Lawrence Yao Free

Professor Lawrence Yao became emeritus in 2024 after 30 years at Columbia University, where he directs the Advanced Manufacturing Laboratory. He was the Chair of the Department of Mechanical Engineering, Columbia University, from 2005 to 2011. Professor Yao was the Editor-in-Chief of the Journal of Manufacturing Science and Engineering (JMSE) for 10 years from 2012 to 2022. The March issue, “Advanced Laser Materials Processing - Honoring Professor Larry Yao”, was dedicated to celebrating the remarkable contributions of Professor Yao. Over the past decades, Dr. Yao has been a pioneering force in laser-based manufacturing and materials processing, significantly shaping our understanding of laser-matter interactions and their practical applications across diverse industries. His research on laser-assisted removal, shaping, and joining of materials, as well as property modification through laser treatments, has paved the way for the development of numerous technologies used today across industries including aerospace, biomedical, renewable energy, art restoration, as well as novel robotics applications in health care areas. His research group has published over 250 technical papers and was honored with five Best Paper awards. Professor Yao's mentorship has fostered a new generation of researchers, with his graduate students now making influential contributions in both academia and industry. Figures 1(a) and 1(b) showcase memorable group gatherings, featuring Professor Yao alongside his former students and their own students, highlighting the enduring legacy of his mentorship.

Professor Yao serves on the editorial board of several other journals. He was the President of North American Manufacturing Research Institute (NAMRI) of Society of Manufacturing Engineers (SME) from 2009 to 2010 and served as the NAMRI Board of Directors from 2002 to 2012. He was the Chair of the Manufacturing Engineering Division (MED) of ASME from 2010 to 2011 and served on the Executive Committee of MED from 2006 to 2011. He was the Board of Directors, Laser Institute of America (LIA), from 2002 to 2008. He has been serving on the Visiting Committee, Department of Scientific Research at Metropolitan Museum of Art in New York, since 2006.

He received many awards including the Milton C. Shaw Manufacturing Research Medal (ASME), Blackall Machine Tool and Gage Award from ASME, Fulbright Senior Scholar Award, Outstanding Paper Award from NAMRI, and Janette and Armen Avanessians Diversity Award, NAMRI/SME Outstanding Lifetime Service Award, ASME Dedicated Service Award, and Columbia University Faculty Excellence Award. He is a Fellow of ASME, SME, and LIA.

The special issue honors his contributions by presenting cutting-edge advancements and exploring the evolving frontiers of the field. It features research that aligns with Professor Yao's visionary approach, highlighting innovations in laser materials processing. We are pleased to receive many papers covering a wide range of advanced laser material processing techniques. The selected papers span a broad spectrum of laser processing techniques, from laser shock peening for enhanced mechanical and electrochemical performance to computational modeling of laser material interactions, and advanced laser additive manufacturing methods. Key topics include predictive modeling, process optimization, and artifitial intelligence (AI)-driven control, all of which reflect the evolving landscape of intelligent manufacturing. Additionally, innovations in laser welding, laser-induced surface engineering, and micro/nanofabrication underscore the transformative potential of laser technologies in aerospace, biomedical, and structural applications.

Laser joining and laser peening are areas where Professor Yao has made groundbreaking contributions. The advancements seen in this special issue, such as laser peening-assisted additive manufacturing [1] and vibration-assisted additive manufacturing [2], exemplify the progress in additive manufacturing research. These papers introduce novel hybrid manufacturing techniques that incorporate laser peening and ultrasonic vibration in additive manufacturing, enabling microstructure and phase control to enhance material properties and mitigate challenges like stress corrosion cracking. Innovations in laser-assisted powder bed fusion and hybrid manufacturing further integrate laser processing with advanced materials science, driving next-generation manufacturing advancements.

Professor Yao's early work in laser micro/nanomachining, microscale laser peening, and peen forming has contributed to advancements in laser-based micro- and nanofabrication. Recent research continues to develop laser techniques for precision applications. In this special issue, Dong et al. [3] demonstrates the use of femtosecond laser pulses for precise manipulation of advanced composite materials. Fang et al. [4] presents a novel approach to reproducing three-dimensional microstructures on Inconel 718 using laser-textured pulse electrochemical machining (PECM) cathodes. The research demonstrates high-precision pattern replication, though challenges such as deviations in concave pattern reproduction highlight the needs for further development. These works collectively advance laser-based manufacturing techniques, paving the way for improved precision, efficiency, and adaptability in micro- and nano-fabrication across various industrial applications.

Professor Yao's research in laser-based structure modification, including ultrafast laser processing of dielectrics and semiconductors, as well as microstructural modification of NiTi shape memory alloys and biodegradable polymers, has made a notable impact on the materials processing industry, shaping industry developments in laser-based modification techniques. In this special issue, Ding et al. [5] provides a practical example of how laser-based surface texturing can improve material properties for applications requiring enhanced corrosion resistance. Over and Yao [6] explored the impact of laser shock peening (LSP) on the electrochemical behavior, wettability, and stress corrosion resistance of additively manufactured stainless steel. These research highlights laser manufacturing as a promising post-processing technique for enhancing corrosion resistance and mechanical reliability in additive manufactured components.

The integration of AI and machine learning in laser materials processing is one of the most exciting frontiers today. In this special issue, Hijam et al. [7] demonstrates the potential for enhancing process precision and optimizing laser interactions with materials. Lin et al. [8] investigated how AI-based optimization, utilizing neural network algorithms can fine-tune manufacturing parameters, enhancing the quality of laser foil printing based additive manufacturing processes. The integration of AI into laser processing not only improves efficiency but also opens new doors for customizable manufacturing solutions.

We extend our deepest gratitude to the authors who contributed their innovative research, the reviewers whose critical insights ensured the highest quality of scholarship, and the editorial teams of JMSE, especially Elizabeth Bruce, for their unwavering support in realizing this issue. Special thanks go to Professor Albert Shih, for his leadership.

We hope this collection of works not only honors Professor Yao's legacy but also serves as a catalyst for new breakthroughs in laser materials processing. His dedication to advancing the field continues to inspire the next generation of researchers and engineers to push technological frontiers and explore novel applications for laser-based manufacturing.