One of the most influential chemical engineers in the last 100 years according to the American Institute of Chemical Engineers, Jacob Israelachvili lost his battle with cancer on September 20. Israelachvili spent more than 30 years as a professor at UCSB with joint appointments in the Chemical Engineering and Materials departments. He led the Interfacial Sciences Lab. His research focused on the various interactions between molecules and surfaces, principally in liquid environments. Israelachvili leaves a legacy of innovation, collaboration, and groundbreaking research.

“Jacob was a legend in his field, a great citizen on campus, and a strong advocate for UCSB and his students,” said Rod Alferness, dean of the College of Engineering. “A countless number of his students, colleagues, and scientists around the world are where they are today because of him.”

Israelachvili received his PhD in Physics in 1972 from the Surface Physics Department of the Cavendish Laboratory at the University of Cambridge in England. After a two-year European Molecular Biology Organization (EMBO) research fellowship at the University of Stockholm, he left for Australia where, from 1974 to 1986, he led an experimental research laboratory devoted to measuring the forces between surfaces.

During the 1970s, Israelachvili made his first significant impact on the scientific community when he designed a new surface-force apparatus (SFA) to measure force interactions in liquid. Until then, researchers only measured the forces between surfaces in a vacuum or air. His device measured the force of attraction and repulsion between two surfaces that could be controlled and measured with better-than-Angstrom (10^-10 m, which is a million times smaller than the diameter of a human hair) precision. The SFA led to the understanding that various parameters, such as salt concentrations, pH, and temperature, could be altered to help identify subtle changes in the forces.

In 1985 he published Intermolecular and Surface Forces, regarded to this day as the definitive textbook in the field of intermolecular forces. He would release multiple updated editions and see his textbook translated into Japanese, Russian and Chinese.  Since 2011, the third edition has been cited more than 30,000 times.

In 1986, Israelchavili joined the faculty at UCSB, where over the course of his career he helped elevate the Chemical Engineering, Materials, and Biomolecular Sciences and Engineering departments to be among the most respected programs in the nation.

“Jacob was one of the senior faculty most responsible for the department’s meteoric rise in reputation and prestige in the late-1980s,” said Brad Chmelka, a chemical engineering professor at UCSB since 1992.  “He helped the department establish a foundation built firmly on deep scientific understanding and great technological impact.”

Israelachvili’s research group at UCSB examined and measured how forces contributed to friction, fluidity, adhesion, lubrication, dissolution, wear, and repulsion. His team received acclaim in 2011 for developing a breakthrough equation that predicted molecular forces in hydrophobic interactions. The equation helps explain why oil and water do not mix, how proteins are structured, and what holds biological membranes together.

Matthew Tirrell worked alongside Israelachvili from 1999-2009 while serving as dean of the College of Engineering. Tirrell, who is currently dean of the Institute for Molecular Engineering at the University of Chicago, described his friend as part of a class by himself.

“Jacob Israelachvili was sui generis in the world of interfacial science,” said Tirrell, a pioneering researcher in the fields of biomolecular engineering and nanotechnology. “A builder of uniquely powerful tools, the author of broadly influential articles and books, and a mentor to hundreds of younger scientists, Jacob gave the world its first direct look into many aspects of interfacial structures and forces. He had a profound ability and patience to focus on his interests, whether it was the new instrument he was designing or the person he was engaging in discussion.”

Israelachvili embraced the collaborative atmosphere at UCSB and broadened the scope of his research to span several fields of study. His group helped to solve several mysteries including: how geckos climb vertical surfaces; the recovery of oil from the ground; the friction and lubrication of mammalian joints; and the physical mechanisms behind autoimmune diseases like multiple sclerosis.

Colleague Herbert Waite, a distinguished professor of biochemistry at UCSB and co-leader of the Materials Research Science and Engineering Center, praised Israelachvili for his spirit of discovery and his willingness to participate in multidisciplinary research. The two worked together to understand how the molecules used by mussels adhere themselves to underwater rocks, an area of research that has since involved many other UCSB researchers.

“During my ten-year research collaboration with Jacob, he often challenged me to go beyond the nanometer length scale of processes like adhesion in living organisms,” said Waite, who worked with Israelachvili to simplify bio-inspired themes for wet adhesion. “I resisted for a bit because biochemists rarely adjust their sights beyond a few hundred nanometers. However, when we bit the bullet, a font of new insights emerged. Not even he imagined what came to be, but he predicted breakthrough.”

The author or co-author of nearly 500 published journal articles, Israelachvili was a Fellow of the Royal Society of London, the oldest scientific academy in continuous existence, whose members include Charles Darwin, Isaac Newton, Albert Einstein, and Stephen Hawking, as well as fellow UCSB faculty member Craig Hawker. Israelachvili was also a member of the U.S. National Academy of Engineering, the U.S. National Academy of Sciences; and  he was a Fellow of the American Physical Society.

“A very small number of scientists through their brilliance and imagination create new bodies of science apparently out of whole cloth. They are the Columbuses and Gallileos, who are driven by a unique conviction that there lies a new continent or a new ocean beyond what is visible on the horizon. Jacob was one of these. And he was more,” said Martin Moskovits, a distinguished professor of chemistry at UCSB. “He was unusually kind and generous, inviting, helping those who wanted to join him in exploring these new scientific territories do so. This generosity of spirit also made him an incomparably successful teacher and mentor, as the hundreds of students he mentored can attest to. He was admired and celebrated literally around the globe. His brilliance and originality, his generosity and kindness and his deep humanity will be greatly missed.”

His many awards included the American Institute of Chemical Engineers (AIChE) Alpha Chi Sigma Award; the Adhesion Society Award for Excellence in Adhesion Science; the American Chemical Society National Award in Colloid and Surface Chemistry; and the Materials Research Society Medal. The American Institute of Chemical Engineers (AIChE) presented him with the William H. Walker Award for Excellence in Contributions to Chemical Engineering Literature in 2012.  The AIChE later named Israelachvili one of the top “One Hundred Chemical Engineers of the Modern Era.” He received the world’s highest award in tribology, the 2013 Tribology Gold Medal Award, for pioneering contributions to the technology and science of friction and wear.  

He is survived by his wife, four children, two grandchildren, and sister. He was 74.

“Jacob was remarkable in so many ways. The depth and impacts of his scientific achievements across disciplines, his exceptional mentoring of students, post-doctorates and junior faculty, and his extraordinary sense of humor,” added Chmelka. “We miss him tremendously and are inspired to propagate his example and legacy.”

On October 26, The Scholarship Foundation of Santa Barbara announced that it is accepting donations for a new scholarship fund established in memory of Professor Israelachvili. The Jacob N. Israelachvili Honors Science Scholarship Fund will support graduate and undergraduate students in chemical engineering, materials, physics, and biochemistry.