Science in brief
SciTech Editor Katarzyna Siewierska gives an account of the biggest stories to emerge from Trinity’s science departments this term
TCD physicists create a sensor from graphene and silly putty
On December 9, the prestigious journal Science published a paper on “Sensitive electromechanical sensors using viscoelastic graphene-polymer nanocomposites” which reports on a very exciting discovery of what is now called G-putty at Trinity’s Amber materials science centre. The team was led by Prof. Jonathan Coleman in Trinity and collaborated with Prof. Robert Young of the University of Manchester.
G-putty was discovered when the researchers added graphene – a material that is essentially a flake of a single layer of carbon – with the popular children’s toy silly putty, i.e. polysilicone. The researchers found that the electrical properties of the material changes with deformation. Then the G-putty is allowed to relax back to its original shape, its original properties are recovered. It is so sensitive that it can detect the footsteps of a spider. When the G-putty is placed on the neck of a person just beside the artery, it can detect the pulse. By placing it on the chest it can measure one’s breathing. The material has a huge potential in sensing applications. The next step is to design a device that can be used in medical sensing and/or diagnostics.
“The behaviour we found with G-putty has not been found in any other composite material. This unique discovery will open up major possibilities in sensor manufacturing worldwide”
In a statement at the TCD School of Physics webpage, Prof. Coleman said , “What we are excited about is the unexpected behaviour we found when we added graphene to the polymer, a cross-linked polysilicone. This material as well known as the children’s toy silly putty. It is different from familiar materials in that it flows like a viscous liquid when deformed slowly but bounces like an elastic solid when thrown against a surface. When we added the graphene to the silly putty, it caused it to conduct electricity, but in a very unusual way. The electrical resistance of the G-putty was very sensitive to deformation with the resistance increasing sharply on even the slightest strain or impact. Unusually, the resistance slowly returned close to its original value as the putty self-healed over time.”
In a statement to the RTE Prof. Coleman remarked, “While a common application has been to add graphene to plastics in order to improve the electrical, mechanical, thermal or barrier properties, the resultant composites have generally performed as expected without any great surprises. The behaviour we found with G-putty has not been found in any other composite material. This unique discovery will open up major possibilities in sensor manufacturing worldwide.”
The launch of the book “Three centuries of physics in Trinity College Dublin” by Dr. Eric Finch
On November 29, TCD celebrated the launch of a book by Dr. Eric Finch entitled “Three centuries of physics in Trinity College Dublin”. The launch in the FitzGerald Library was attended by Provost Patrick Prendergast, previous Provost John Hegarty, family members, friends, members of staff and students.
Dr. Eric Finch is a Fellow Emeritus of TCD and a former Professor at the school of physics. He was the last person appointed by Ernest Walton before his retirement. Walton was a student and later professor and head of school of physics at TCD and is most famous for sharing Nobel Prize in 1951 with John Cockroft for the artificial splitting the atom. Dr. Finch has been a member of staff at the school of physics for over 40 years. In that time he has heard many stories from his older colleagues and also witnessed many important events, which he describes in his book. In September 2016 Prof. Finch was invited to give an invited talk on his research at the 2nd International Conference on the History of Physics in Pöllau in Austria.
“Trinity and its physics department survived the difficult times and both experienced a remarkable revival that began in the 1960s”
The book describes the development of physics in TCD covering the period from 1683 to 1984. It starts with the early accounts of teaching of physics and its formalisation with the appointed of Richard Helsham to the Erasmus Smith Professorship of Natural and Experimental Philosophy in 1724. Later comes the 19th century which can be considered the golden age of physics at Trinity. It was the time of some of the greatest physicists that ever walked the college grounds such as William Rowan Hamilton, James MacCullagh, Humphrey Lloyd, George Francis FitzGerald and many others. Following the golden age came very difficult times with the break out of the Easter Rising and Ireland’s War of Independence.
Trinity and its physics department survived the difficult times and both experienced a remarkable revival that began in the 1960s. The book ends in 1984 which marks the arrival of Prof. Denis Weaire and his appointment to the Erasmus Smith Professorship of Natural and Experimental Philosophy. This book is an excellent read. It can be a perfect Christmas gift for anyone who would like to know more about the history of physics in Trinity and the amazing people who have worked here.