A team of researchers from AMBER, the Science Foundation Ireland funded materials science centre based in Trinity College Dublin, have made a breakthrough in the area of material design – one that challenges the commonly held view on how the fundamental building blocks of matter come together to form materials. Professor John Boland, Principal Investigator in AMBER and Trinity’s School of Chemistry, researcher Dr. Xiaopu Zhang, with Professors Adrian Sutton and David Srolovitz from Imperial College London and University of Pennsylvania, have shown that the granular building blocks in copper can never fit together perfectly, but are rotated causing an unexpected level of misalignment and surface roughness. This behaviour, which was previously undetected, applies to many materials beyond copper and will have important implications for how materials are used and designed in the future. The research was published today in the prestigious journal, Science*. The Intel Corp. Components Research Group also collaborated on the publication.
Electrical, thermal and mechanical properties are controlled by how the grains in a material are connected to each other. Until now, it was thought that grains, which are made up of millions of atoms, simply pack together like blocks on a table top, with small gaps here and there. Professor Boland and his team have shown for the first time that nano-sized grains in copper actually tilt up and down to create ridges and valleys within the material. Nanocrystalline metals such as copper are widely used as electrical contacts and interconnects within integrated circuits. This new understanding at the nanoscale will impact how these materials are designed, ultimately enabling more efficient devices, by reducing resistance to current flow and increasing battery life in hand-held devices.
Professor John Boland, Principal Investigator in AMBER and Trinity’s School of Chemistry, said, “Our research has demonstrated that it is impossible to form perfectly flat nanoscale films of copper and other metals. The boundary between the grains in these materials have always been assumed to be perpendicular to the surface. Our results show that in many instances these boundaries prefer to be at an angle, which forces the grains to rotate, resulting in unavoidable roughening. This surprising result relied on our use of scanning tunnelling microscopy which allowed us to measure for the first time the three-dimensional structure of grain boundaries, including the precise angles between adjacent grains.”
He added, “More importantly, we now have a blueprint for what should happen in a wide range of materials and we are developing strategies to control the level of grain rotation. If successful we will have the capacity to manipulate material properties at an unprecedented level, impacting not only consumer electronics but other areas such as medical implants and diagnostics. This research places Ireland yet again at the forefront of material innovation and design.”
Professor Boland is Dean of Research at Trinity, a fellow of Trinity College and a fellow of the American Association for the Advancement of Science. He was the Laureate of the 11th ACSIN Nanoscience Prize (2011) and was awarded a prestigious ERC Advanced Grant in 2013.
* Zhang X, Han J, Plombon JJ, Sutton AP, Srolovitz DJ, Boland JJ. Nanocrystalline copper films are never flat. Science 28 July 2017
The porous, ‘sponge’-type molecules have an enormous internal surface area
This allows their use as ‘molecular flasks’ or ‘molecular containers’ that change the reactivity and properties of encapsulated molecules
Scientists from Trinity College Dublin and AMBER, the Science Foundation Ireland-funded materials science research centre hosted in Trinity College Dublin, have created ‘molecular cages’ that can maximise the efficiency of converting molecules in chemical reactions, and that may in future also be used as sensors and drug-delivery agents. The cages can be packed with different molecules, many of which have a specific task or functionality. Incredibly, a teaspoon of powder containing these cages provides a greater internal surface area to boost reactivity and storage capacity than would be provided by an entire football field (4000 m2/g).
This enormous intrinsic surface area relative to the weight of the structure in combination with the solubility offers great promise for energy conversion, while the structure blueprint (hollow, with sub-cages) allows different molecules to be discretely contained within. This latter feature is key in increasing the potential uses for these ‘metal-organic-organic polyhedra’ (MOP), because it means materials can be packed so as to react only when specific conditions present themselves.
One such example is in bio-sensing and drug-delivery, with a biological cue required to kick-start a chemical reaction. For example, a drug could be encapsulated in one of these MOP in the knowledge that it would only be released at the specific target site, where a specific biological molecule would trigger its release.
The researchers behind the breakthrough, which has just been published in leading international journal Nature Communications, also hope to develop light-active porous, metal-organic materials for use in green energy. The dream would be to create a molecule that could simply use light to convert energy – essentially replicating the way plants produce energy via photosynthesis.
Professor in the School of Chemistry at Trinity College Dublin, and Investigator in AMBER, Wolfgang Schmitt, led the research. He said: “We have essentially created a molecular ‘flask’ or better ‘sponge’ that can hold different molecules until a specific set of conditions spark them into life.”
“Hollow cage-type molecular structures have attracted a lot of scientific attention because of these features, but as the number of potential applications has grown and the target systems and environments become more complex, progress has been hampered by the lack of structures with sufficiently large inner cavities and surface areas.”
“The MOP we have just created is among the largest ever made, comprising a number of internal sub-cages, providing numerous different binding sites. The nano-sized compartments can potentially change the reactivity and properties of molecules that are encapsulated within the confined inner spaces and, as such, these cages can be used to promote distinct chemical reactions. Thus, these molecules have the potential to mimic biological enzymes.”
The journal article describes the structure of the new cage molecule, which is composed of 36 copper atoms and is made up of 96 individual components. The article can be read at Nature Communications.
A new collaboration between researchers at RCSI (Royal College of Surgeons in Ireland), and Trinity College Dublin (TCD) as part of the AMBER, SFI funded materials science centre in conjunction with Integra LifeSciences, a world leader in medical technology, aims to develop, and bring to the market, a new product to facilitate the repair of large nerve defects in the body. This €1.4 million research programme will run for three years.
This project is led by Prof Fergal O’Brien (Dept. of Anatomy, RCSI & Deputy Director in AMBER) in partnership with Prof Conor Buckley from the Trinity Centre for Bioengineering (TCD).
Peripheral nerves link the brain and spinal cord to the other parts of the body, such as the muscles and skin. They can be damaged through disease, trauma and burns resulting in interference with the brain’s ability to communicate with tissues resulting in the loss of motor or sensory function to muscles and skin. This can have significant deterioration in a patient’s quality of life.
Peripheral nerve injury is a major clinical problem and is known to affect more than 5 million people worldwide every year. It is estimated that five percent of multiple trauma patients have peripheral nerve injuries. Prompt surgical intervention is needed but if the injury size is larger than five millimetres, the primary treatment option available in most cases is by autograft which involves removal of nerve tissue from another part of the patient’s body and transplantation to the site of injury. Unfortunately, autografts are hampered by a number of issues including the limited availability of donor tissue and often functional recovery for patients can be poor. As a result the RCSI & TCD team in AMBER are working with Integra LifeSciences to develop a next generation nerve graft capable of repairing large nerve defects without the need for invasive secondary surgeries.
RCSI’s collaboration with Integra began in 2005 and has deepened in the intervening years through the AMBER Centre. This current project marks the second engagement in the area of peripheral nerve repair between the parties. The first project was successfully completed at the end of 2016 and resulted in a patent being filed on technology generated under the project. This current engagement builds on this research.
Dr. Simon Archibald, Vice President and Chief Scientist from Integra LifeSciences said, “The demand for nerve repair biomaterials is increasing due to the aging population and rising number of nerve injuries and nerve surgeries. Our aim is to treat largescale nerve defects in the body and introduce this new technology to our portfolio of existing nerve repair products.”
Professor Fergal O’Brien, Professor of Bioengineering & Regenerative Medicine & Deputy Director of AMBER said “Building on a wealth of expertise in biomaterials development from the Tissue Engineering Research Group at RCSI, our hope is to work with Integra to see this new technology translate to the benefit of patients and society.”
Associate Professor in Chemistry at Trinity College Dublin, Aidan McDonald, has won the prestigious Royal Society of Chemistry Sir Edward Frankland Fellowship for 2017. The Fellowship is awarded for the encouragement of research in organometallic chemistry or the coordination chemistry of transition metals. This annual Fellowship is renowned in the area of chemistry, as many previous winners of the Fellowship have gone on to win Nobel prizes for their research.
Professor McDonald investigates the chemistry of transition metals (metals from the middle of the periodic table including iron, nickel, and copper). His group’s research focuses on how such metals can facilitate more environmentally friendly chemical manufacturing, and the development of facile methods for processing 2D nanomaterials. In 2015, Aidan was also awarded an ERC starting grant, and in late 2016 he was presented with a Royal Society/SFI University Research Fellowship. Both are awarded to outstanding early career scientists.
Professor McDonald said: “I am deeply honoured to receive this award, and am very grateful to my colleagues who supported my nomination. I am also extremely grateful to the School of Chemistry in Trinity and the Science Foundation Ireland funded AMBER research centre for supporting my group’s research efforts in this early phase of my career.”
Dr Robert Parker, chief executive of the Royal Society of Chemistry said: “It is an honour to celebrate the innovation and expertise of our community through our prizes and awards. We know that chemistry can be a powerful force for good, and quality research and communication of that research are more important than ever before.
“Our charitable mission is to advance excellence in the chemical sciences, and we are proud to celebrate our inspiring and influential winners, who share that mission.”
Award winners are evaluated for the originality and impact of their research, as well as the quality of the results, which can be shown in publications, patents, or even software. The awards also recognise the importance of teamwork across the chemical sciences, and the abilities of individuals to develop successful collaborations.
The annual awardee of the Royal Society of Chemistry Sir Edward Frankland Fellowship receives £2000, a medal and a certificate of commendation. An illustrious list of 50 previous winners of the Royal Society of Chemistry’s awards have gone on to win Nobel Prizes for their pioneering work, including all of the 2016 chemistry winners, Jean-Pierre Sauvage, Fraser Stoddart and Ben Feringa.