Chemist who helped develop MRI scanning technology
RICHARD ERNST, who has died aged 87, was the sole recipient of the 1991 Nobel Prize in Chemistry, which he won for his contribution to the development of Nuclear Magnetic Resonance (NMR) imaging, the technology which underlies magnetic resonance imaging (MRI), a technique used in hospitals around the world to investigate the inner workings of the body.
He was not the inventor of NMR. The technology was made possible by numerous scientists over a period of more than 50 years. Felix Bloch and Edward Purcell had shared the Nobel Prize in Physics in 1952 for showing that radio waves could create a magnetic field that could alter the alignment and resonance frequency of an atom’s nucleus. They showed that when the radio waves are turned off, the nucleus tends to revert to its original position, emitting an electromagnetic signal that can be measured to analyse the chemical involved.
When Ernst began his research a few years later, there were relatively few practical applications for NMR beyond chemical analysis. Ernst’s contributions in the 1960s included the so-called Fourier Transform NMR, a technique involving highly complex mathematics, which greatly increased the sensitivity of NMR, allowing the study of individual molecules for the first time.
His research also led to the development of twodimensional NMR, for the determination of the physical and chemical properties of atoms, as well as medical magnetic resonance tomography (MRT), an imaging technique used to investigate the human body.
In the mid 1970s Ernst developed methods of determining the threedimensional structure of chemical and biochemical compounds, now used also to study the rates of chemical reactions.
Richard Robert Ernst was born on August 14 1933, in Winterthur, Switzerland, where his father worked as a teacher. He became fascinated by chemistry as a child after finding an old box of chemicals that had belonged to an uncle. He began to read chemistry books and, to his parents’ consternation, conducted experiments in the family basement: “I became almost immediately fascinated by … trying out all conceivable reactions … some leading to explosions, others to unbearable poisoning of the air in our house.”
After taking a degree in chemical engineering, followed by a doctorate in physical chemistry at the Federal Institute of Technology in Zurich (ETH Zurich), he crossed the Atlantic to join Varian Associates, a company in Palo Alto, California, where he began his research.
He returned to the Federal Institute of Technology in Zurich in 1968, and remained there, teaching and carrying out research, until 1998, retiring as a professor.
Ernst, who won numerous scientific awards, viewed himself, modestly, as a “toolmaker” rather than as a scientist. He learnt about his Nobel Prize when he was woken from his slumbers by a flight attendant on a transatlantic flight, to be ushered into the cockpit to speak to the Nobel committee over the radio.
As a child Ernst had played the cello and thought of becoming a composer. He continued to play the instrument throughout his life and had an encyclopedic knowledge of classical music. He also became an expert in Tibetan art, amassing an impressive collection.
In his Nobel essay he stressed the importance of scientists having interests outside their specialities, but also regretted the impact of health and safety culture on his chosen field: “Sometimes people say chemistry is too dangerous – you can’t do this and that with children – but that’s not really true. There are a few rules which you have to obey, but otherwise you can do a lot of experiments.”
Richard Ernst is survived by his wife Magdalena, née Kielholz, and their three children.
Richard Ernst, born August 14 1933, died June 4 2021