The ESRF User Organisation has awarded the title of Young Scientist of the year to Dr Andrew Cairns, 27, for his ground breaking studies of negative linear compressibility. On behalf of the ESRF User Organisation, Andrew was presented the award by Professor Massimo Altarelli, at the 26th ESRF User Meeting in Grenoble, on 8th February 2016.
The panel of judges, made up of eminent X-ray scientists selected by Massimo Altarelli, received many high quality nominees for the prize, making the final choice a difficult exercise.
“Although the existence of negative linear compressibilities (NLC), or the expansion of materials under pressure, has been known for many decades, Andrew Cairns, using ESRF X-rays, identified materials with the strongest NLC effect yet known, at least one order of magnitude larger than in previous known cases,” said Massimo Altarelli.
The work that earned Andrew Cairns this recognition was published in Nature Materials in 2013 and received much attention, not only in scientific spheres but also in the general media.
"Andrew Cairns has done outstanding work on the mechanical properties of metal-organic frameworks, in particular concerning the occurrence of negative linear and negative area compressibility in cyanide systems, and I was delighted to hear that he has received the Young Scientist of the Year award from the ESRF User Organisation," said Tony Cheetham, Fellow of the Royal Society and eminent scientist in the field of materials chemistry.
“Being named as Young Scientist is a huge surprise, and a great honour. Of course this work would not have been possible without the help of many colleagues who I would like to thank: those at Oxford, collaborators across Europe, and the very patient ESRF scientists who helped with our original experiments,” said Andrew Cairns on receiving the prize.
Negative compressibility occurs when a material expands under pressure, rather than shrinking. Whilst thermodynamic laws forbid the volume of the material to expand, they do not dictate that it must shrink in every direction. “Take the example of a foldable wine rack,” says Andrew. “Its collapsed (low-volume) state is narrower but ‘taller’ than the expanded (high-volume) state. This expansion with volume reduction is negative linear compressibility (NLC).”
Until recently very few NLC materials were known, and of those the expansion was small in comparison to the normal contraction of common engineering materials. This is where Andrew’s work has made such a significant impact. His research brings together mechanistic understanding of the phenomena with the knowledge of how to engineer materials on the atomic scale in a class of materials known as molecular frameworks. Since the discovery of extreme NLC in these structures, more NLC materials are being identified.
“It’s like a game of Meccano”, says Andrew. “Molecular frameworks are made up of metal nodes with certain shapes, which for us act like hinges, linked together with molecules that act as ‘struts’. There is a huge choice of metals and linkers available, and part of the challenge is to select the most appropriate candidates to target functionality. So for NLC we’re usually looking for materials that resemble the famous wine rack! ”
The applications for NLC materials is wide: sensitive pressure sensing, pressure driven actuators, the development of artificial muscles, bullet-proof clothing, fibre optics for telecommunications, or compensators for other undesirable material expansion.
Although finding application for his research is high on the list of concerns, it does not seem to be the main motivation for Dr Cairns. “I’m attracted to exotic materials that break the rules. They do the opposite to what’s expected of them and for me that’s fascinating.”
Andrew has been studying materials showing unusual properties since 2010. It became the focus of his PhD thesis at the University of Oxford in the UK, which he completed in 2015 and for which he obtained a commendation from the Mathematical, Physical and Life Sciences Division of Oxford University, a rarity reserved for exceptional reports.
His thesis director, Professor Andrew Goodwin, Department of Chemistry, Oxford University, was delighted to hear the news of Andrew’s latest award. “This is wonderfully deserved recognition for a supremely talented young researcher. Andrew is a careful experimentalist, with a sharp analytic mind and excellent scientific instincts. But, above all, he is a creative researcher with no fear of the tricky and rewarding science between disciplines.”
Andrew Cairns, left, with Prof. Andrew Goodwin, at the ESRF User Meeting 2016 where Prof. Goodwin gave a keynote lecture on "supramolecular interactions in the solid state: flexibility, frustration, and function". Credit: ESRF/C. Argoud.
Despite his genuine modesty and fresh demeanour, Andrew is well accustomed to receiving prizes. In fact his work has been receiving recognition ever since he first triumphed in high school chemistry Olympiads, having being nudged in this direction by an observant and conscientious teacher. The same whose influence led to an application to study at Oxford.
“I spent all my childhood trying to find out how things work. Taking things apart and putting them back together again. Participating in the Olympiads made me realise how much I love problem-solving. I never thought I’d do a PhD or be working at the forefront of a field of research. I feel privileged to be able to have a job where I can do what I really love doing every day.”
As well as carrying out challenging high-pressure experiments in his new role at the ESRF, he hopes to continue to design and make new materials with exciting properties. For him, this process is creative as well as technical: following instinct to what might be interesting, dreaming up awesome new structures, imagining how they might respond when put under pressure. “Sometimes, you just don’t know where the idea will come from.”
It was during the first year of his PhD studies that Andrew discovered the ESRF. In late 2011, he obtained three days of beamtime on BM01, the Swiss Norwegian beamline, to carry out the experiments that compensated him with a “Eureka” moment, and the beginnings of a scientific breakthrough.
“During the first year of my PhD, I was at the ESRF testing the materials that our group had made during my Masters. I remember we were plodding along, methodically testing the materials and then one sample started showing a response completely different to the others. I remember that feeling, walking over to the canteen for lunch, in a bit of a haze thinking “What is going on?” “What are we going to do with this?” then realising that I’d never seen this before, and nobody else had either!”
Of course, a lot of work was needed in between this first inkling that something exceptional was taking place and getting all the data together to confirm and present the findings. Andrew clearly remembers that “Eureka” moment, however, and how it helped him in those long months before publication. “No matter how few and far between those moments, they are a powerful driver for perseverance.”
The undergraduate chemistry degree at Oxford University includes one year of research following on from a mainly theoretical programme. It was this practical experience that was critical for Andrew’s career path; the deciding moment when he knew he wanted to work in research. After the PhD he saw the ESRF was seeking a post-doctoral fellow for its high pressure beamline, ID27. He was attracted by the possibility to continue his own research projects while learning more techniques and experimental skills, at the same time as meeting people to develop collaborations and gain momentum on projects. Andrew joined the ESRF in September 2015 and hopes this move will give the opportunity of many more discoveries like those that started it all in 2011.
“There’s still so much to learn. Just how large can these responses be? How do we go about engineering materials with complex combinations of properties? Can we tailor and tune properties to the optimum that might be demanded for a particular application? Needless to say these next steps are very exciting,”
Each year since 1995, the Young Scientist Award (YSA) is presented to a scientist aged 35 or under in recognition of outstanding work carried out at the ESRF. The ESRF Users Organisation chooses a chairperson for the YSA. The chairperson then forms a selection committee composed of distinguished scientists whose expertise covers the most important areas of synchrotron science. The panel calls for nominations from institutes around the world and evaluates nominees on the basis of the following criteria:
• Significant and personal contribution to either a novel method or technique, or to the advancement of a particular field based on ESRF measurements
• Quality and quantity of publications, conference contributions and responsibilities
• Importance of the specific field for synchrotron science research
For the 2016 YSA the selection committee was set-up and chaired by Prof. Massimo Altarelli, Chairman and Managing Director of the European XFEL, Hamburg, Germany. Professor Altarelli was Director of Research at the ESRF from 1987-1993.
The panel was composed of the following members: