systems and was recognized as the world’s leading authority in metallic additive manufacturing.

In addition, he broke new ground in quality-assured manufacturing through diagnostics and process control. His research in this area continues to provide the fundamental and technological breakthroughs required to establish a new manufacturing paradigm for “certify-as-you-build,” a robust and viable approach to reduce manufacturing waste due to problems with quality.

Professor Mazumder was an innovator of the closed-loop DMD process, a method for 3-dimensional printing with metals that was dubbed “the third industrial revolution” by Economist magazine in April 2012. Jyoti and his colleagues invented an in situ diagnostic to identify solid-state micro-structure from the characteristics of the plasma emission during laser processing. This method has revolutionized the practice of materials synthesis.

He sought to bring scientific understanding to the interactions of laser emission and materials and the application of laser manufacturing to satisfy various needs. He dedicated his professional career to establishing the science and engineering base for laser-materials interactions to meet these needs, and he shared his deep knowledge through his publications, patents, students, and technology transfer.

As an example, the three-dimensional heat transfer model that he developed as part of his PhD thesis for laser processing of titanium alloys with a CO₂ laser was adapted by McDonnell Douglas (subsequently acquired by Boeing) for commercial application. And in 1992 Jyoti developed the mathematical model for Nd-YAG laser drilling used by the General Electric Aircraft Engine Group; at the time the company made 18 billion laser-drilled holes annually for its turbines and controlled the majority of the aircraft turbine market worldwide. The new technique was an industry game changer.

From his earliest days in research, Jyoti built the science base for laser-materials interaction and related applications. In 1994 he published in Physical Review models for nanoparticle generation by laser ablation. In 2015 he and his colleagues

published in Nature: Scientific Reports a prediction of dendrite orientation during additive manufacturing with nickel super alloy. He created the first self-consistent comprehensive mathematical model for laser material processing and subsequently applied that theory to additive manufacturing. He constructed the theory by incorporating relevant new phenomena, and also invented measurement techniques to validate the models using physics-based diagnostics for in situ measurement and monitoring. For example, he invented and patented methods to measure the fluid velocity and resultant surface deformation during laser processing.

Jyoti’s breakthrough impacts are summarized below:

• He developed the first 3D self-consistent energy transfer model for laser processing.
• He was the first to identify the mechanism of diffusion in laser surface alloying.
• He authored the first scientific paper on the role of surface tension flow for laser melting.
• He developed and patented the first closed-loop DMD technology.
• He was first to develop and publish on microchannels for implantable artificial lungs.

Besides McDonnell Douglas (Boeing) and General Electric, he transferred his technology to other major industries such as Nissan and Ford. He also created three startup companies:

1. He was the founding director of Quantum Lasers, applying laser cladding technology for repair of engineering components such as aircraft turbines. Quantum Lasers became a major maintenance partner for Delta Airlines and Honeywell Corporation.
2. He patented the first closed-loop DMD technology, where components can be made directly from CAD, and commercialized the technology through a startup called POM Group Inc., which was launched with $25 million venture capital.

3. He launched his third company, SenSigma LLC, in 2012 with the encouragement of the University of Michigan to commercialize his patents on detection of defects and phase transformation during laser manufacturing.

Prof. Mazumder was the inventor on 25 patents in closed-loop metal deposition machines. A prolific author, he published some 400 papers, and coauthored books on laser chemical vapor deposition and on laser materials processing.

In addition to his NAE membership, he was a fellow of the American Society of Mechanical Engineers (ASME), American Society of Metals, and International Academy of Photonics and Laser Engineering, and he was named president of the Laser Institute of America in 2000.

For the National Academies he served on the Committee on Connector Reliability for Offshore Oil and Natural Gas Operations (2016–18), and for the NAE he served on the Mechanical Engineering Search Committee (2015–19; chair, 2017–18).

In recognition of his accomplishments, Jyoti received several notable honors: the Distinguished University Innovator Award (2012) from the University of Michigan, Adams Memorial Membership Award (2007) from the American Welding Society, Schawlow Award (2003) for seminal contributions to laser application research from the Laser Institute of America, and, from ASME, the Thomas A. Edison Patent Award (2010) for inventing the first closed-loop direct metal deposition system and the William T. Ennor Manufacturing Technology Award (2006).

Apart from all his professional accomplishments, he was a wonderful human being who was loved by so many during his life. He leaves a legacy of bright engineers throughout the world carrying on his teachings and research spanning decades. He is deeply missed by his family and by colleagues, students, and friends all over the world.

His two sons, Debashis and Debayan, had a father who always lived by example and instilled the value of giving your best effort to everything you do. He was a loving husband

to Aparajita and they lived an exciting life building their careers, raising their children, traveling the world, and enjoying wonderful moments with family and friends. Jyoti will be forever loved.