He was a Nobel Prize nominee, internationally known in his chosen field — surely one of Rotorua’s most successful sons. Yet most in the city have likely never heard Robert “Digby” Macdonald’s name. Reporter Annabel Reid tells the story of a Reporoa farm boy who became a renowned scientist.
A Nobel Prize-nominated scientist, adventurous farm boy, devoted family man, and proud son of Reporoa “never forgot his roots”.
Professor Robert “Digby” Macdonald died in California on June 11, aged 81, after a long battle with illness.
The middle child of five, Macdonald grew up with three sisters and a brother on a Reporoa farm bordered on two sides by the Kaingaroa Forest.
His sister Rhondda Sweetman was exactly two years younger to the day.
Sweetman said moving on to the farm, the family initially lived in tents, with electricity limited to only the cowshed.
Life in early 1950s Reporoa was “real pioneering” and “wasn’t easy”, she said.
Stormy weather sometimes blew their tents down at night, forcing them to set up camp with other people.
“So how does someone come out of a situation like that and go on to achieve?” Sweetman said.
She said it came from an unspoken household expectation. A quiet belief instilled by their parents that they would all succeed and “simply expected” that each of them would go on to university.
“We were a bit different as a family [for the time],” Sweetman said.
Their mother, Francis Helena Macdonald, was a graduate from Otago University, and their father, Leslie Graham Macdonald, was a “pretty bright chap” too, despite missing out on formal education due to the Great Depression, she said.
Sweetman said the family moved into a three-room bach, like many settlers in Reporoa had at the time, and lived there for about two years before shifting into a “proper house” when she was 6, Macdonald 8.
Surrounded by books and encouraging words, the Macdonald parents urged their kids to master any and every academic pursuit you could think of, Sweetman said.
Macdonald became a leading figure in science for more than five decades.
Macdonald earned a master’s degree in chemistry from the University of Auckland before moving to Canada to complete his PhD in electrochemistry at the University of Calgary.
From 1984 to 1991, he worked at California-based research centre SRI International (formerly the Stanford Research Institute) where he led the Chemistry Laboratory and the Materials Research Laboratory, served as deputy director of the Physical Sciences Division, and spent two years as vice president.
He went on to hold senior academic roles, including Distinguished Professor at Pennsylvania State University from 2003 and Professor of Materials Science and Engineering at Ohio State University.
In 2012, he was appointed Professor of Residence in the Departments of Materials Science and Engineering and Nuclear Engineering at the University of California, Berkeley.
Over his career, Macdonald published more than 1000 peer-reviewed papers, authored four books, and earned global recognition in corrosion science.
The papers he treasured most were the ones co-authored with his wife, Professor Mirna Urquidi-Macdonald, who worked alongside him at Pennsylvania State University’s Department of Engineering Science and Mechanics.
His research transformed the world’s understanding of how metals resist corrosion, with applications widely adopted in the nuclear power industry.
Macdonald’s work in electrochemical systems laid the groundwork for advancements in energy storage, battery design, nuclear reactor safety, and advanced materials. Using electrochemical impedance spectroscopy, he pioneered innovative models for data interpretation and was among the first to apply Kramers–Kronig transforms to validate results.
Renowned for bridging theory and practice, he combined rigorous mathematical modelling with practical engineering solutions, leaving a lasting mark on both the scientific community and industry.
Sweetman said he was nominated for the Nobel Prize in Chemistry in 2011.
The Australasian Corrosion Association website said Macdonald had been awarded “every prestigious international prize that is available to corrosion scientists”.
Colleagues and collaborators often described him as intensely curious, intellectually fearless, and deeply principled.
“He was just a born scientist,” Sweetman said.
To begin with, “Digby wasn’t particularly interested in school”, Sweetman said, but once he discovered science, “it was all he ever wanted to do”.
She said he once spent hours building a gyrocopter, a type of aircraft using a freely turning rotary wing to fly vertically, which “fortunately, never flew”.
Much later in life he did “of course” fly his privately owned plane, “as people do”, she said.
Macdonald attended Reporoa Primary School and College, where classes often only had about 10 students. The college offered education only up to Year 11, and he became the second student to earn a school certificate, after his older sister, Justine.
Their mother was also a past teacher of Reporoa College.
For Macdonald’s final two years of secondary school, he went to Auckland Grammar School.
Sweetman likened her brother to the Pied Piper of Hamelin where much like the piper in the tale, Macdonald drew crowds who eagerly followed him.
On the school bus, Sweetman said he would sit surrounded by “adoring kids”, telling them stories about science.
“He was in many ways very charismatic”, she said, but a “very unassuming person”.
“Even though he achieved a lot, he was just my big brother.”
Sweetman said they were all “adventurous kids”. Macdonald built trolleys for he and his siblings to go “tearing down the slopes”, and he was often found catching fish and eels so long they stretched from the ground, around his neck, and back to the ground again.
“He was a great brother.”
His adventures continued later into his life as he was an avid sailor, spending many happy days with family, friends and students boating off the coasts of New Zealand, the San Francisco Bay, the Caribbean, and the Tampa area.
Digby is survived by his spouse, Mirna Urquidi-Macdonald, and his children, Leigh Dagberg, Matthew Macdonald, Duncan Macdonald, Nahline Gouin-Mecum, and five grandchildren.
Sweetman said her brother was a very proud family man and friend. He was “just an ordinary man” who never forgot where he came from.
Annabel Reid is a multimedia journalist for the Bay of Plenty Times and Rotorua Daily Post, based in Rotorua. Originally from Hawke’s Bay, she has a Bachelor of Communications from the University of Canterbury.