Lawrence Y. Yao

Yao has pioneered research in laser materials processing, including laser-assisted removal, shaping, joining, and property modification of various materials, and innovative laser applications in renewable energy, biomedical, and art restoration fields.

The aim of his research group has been to understand the physics of process/material interactions, leading to positive impacts on quality and productivity. His group has strived to achieve this aim via a combination of novel experimentation, materials characterization, and theoretical/numerical investigations. Yao’s work also includes novel robotics applications in health care areas.

Recent projects from Yao’s research group include: (1) Mitigation of stress corrosion cracking via laser shock peening , where high intensity laser pulses of nano-second duration induce compressive residual stress deep into target material surface and as a result, potential crack initiation and propagation due to hydrogen embrittlement are deterred and arrested. This mitigation capability is of significant importance in a range of industrial applications including in light water reactors for nuclear power generation. (2) Shaping of metallic foam via laser-forming process for shock absorbing, weight reduction, and thus sustainability applications in aerospace and automotive industries. Laser-induced steep temperature gradient in foam plates enables effective shaping without cracking and cell crashing often occurring in mechanical shaping. (3) Interlaminar toughening of composites for wind turbine blades application, where delamination is of major concern. Methods based on ductile interleaf placement and on promoting diffusion and precipitation bonding have been developed and experimental results show significant increase in fracture energy. This is a joint project with GE Global Research. Yao’s group has also collaborated with Center for Radiological Research at Columbia University Medical Center on a robotized system development for high-throughput biodosimitry (see Profile).

Yao joined the faculty of Columbia Engineering in 1994 and served as Chair of the Mechanical Engineering Department between 2005 and 2011. He received the Milton C. Shaw Manufacturing Research Medal from the American Society of Mechanical Engineers (ASME) in 2015 and the Blackall Machine Tool and Gage Award from ASME in 2006. Yao also served as president of the North American Manufacturing Research Institution from 2009-2010 and currently serves as editor of the Journal of Manufacturing Science and Engineering of ASME.

Research Areas

• Manufacturing and Design
• Nontraditional Manufacturing
• Laser Materials Processing
• Laser-Assisted Material Removal, Shaping, and Surface Modification
• Laser Applications in Industry and Art Restoration
• Robotics in Industry and Health Care
• Mechanical Engineering