Temperature measurements in our daily life are typically performed by bringing a thermometer in contact with the object to be measured. However, measuring the temperature of nanoscale objects is a much more tricky task due to their size - up to a thousand times smaller than the width of a human hair.
Pioneering research, published in Nature Nanotechnology, has now developed a method to accurately measure the surface temperature of nanoscale objects when they have a different temperature than their environment. A team led by Dr Janet Anders at the University of Exeter and Professor Peter Barker at University College London have discovered that the surface temperatures of nanoscale objects can be determined from analysing their jittery movement in air - known as Brownian motion.
"This motion is caused by the collisions with the air molecules" said Dr Anders, a quantum information theorist and member of the Physics and Astronomy department at the University of Exeter. "We found that the impact of such collisions carries information about the object's surface temperature, and have used our observation of its Brownian motion to identify this information and infer the temperature."
The scientists conducted their research by trapping a glass nanosphere in a laser beam and suspending it in air. The sphere was then heated and it was possible to observe rising temperatures on the nanoscale until the glass got so hot that it melted. This technique could even discern different temperatures across the surface of the tiny sphere.
"When working with objects on the nanoscale, collisions with air molecules make a big difference", says Dr. James Millen from the team at University College London. "By measuring how energy is transferred between nanoparticles and the air around them we learn a lot about both".
Accurate knowledge of temperature is needed in many nanotechnological devices because their operation strongly depends on temperature. The discovery also informs current research which is working towards bringing large objects into a quantum superposition state. It further impacts on the study of aerosols in the atmosphere and opens the door for the study of processes that are out of equilibrium in a controlled setting.
Brownian motion is named after the Scottish botanist Robert Brown who, in 1827, noted that pollen move through water even when the water is perfectly still. Albert Einstein published a paper in 1905 that explained in precise detail how this movement was a result of the pollen being pushed by individual water molecules, eventually leading to the acceptance of the atomistic nature of all matter in science.
This research was funded by the Engineering and Physical Science Research Council (EPSRC).
For further information please contact:
University of Exeter Press Office
+44 (0)1392 722405 or 722062
About the University of Exeter
The University of Exeter is a Russell Group university and in the top one percent of institutions globally. It combines world-class research with very high levels of student satisfaction. Exeter has over 18,000 students and is ranked 8th in The Times and The Sunday Times Good University Guide league table, 10th in The Complete University Guide and 12th in the Guardian University Guide 2014. In the 2008 Research Assessment Exercise (RAE) 90% of the University's research was rated as being at internationally recognised levels and 16 of its 31 subjects are ranked in the top 10, with 27 subjects ranked in the top 20. Exeter was The Sunday Times University of the Year 2012-13.
The University has invested strategically to deliver more than £350 million worth of new facilities across its campuses in the last few years; including landmark new student services centres - the Forum in Exeter and The Exchange on the Penryn Campus in Cornwall, together with world-class new facilities for Biosciences, the Business School and the Environment and Sustainability Institute. There are plans for another £330 million of investment between now and 2016.
For further information:
University of Exeter
+44 (0)1392 722405 or 722062
Duncan Sandes | Eurek Alert!
Introducing the disposable laser
04.05.2016 | American Institute of Physics
New fabrication and thermo-optical tuning of whispering gallery microlasers
04.05.2016 | Okinawa Institute of Science and Technology (OIST) Graduate University
Using an ultra fast-scanning atomic force microscope, a team of researchers from the University of Basel has filmed “living” nuclear pore complexes at work for the first time. Nuclear pores are molecular machines that control the traffic entering or exiting the cell nucleus. In their article published in Nature Nanotechnology, the researchers explain how the passage of unwanted molecules is prevented by rapidly moving molecular “tentacles” inside the pore.
Using high-speed AFM, Roderick Lim, Argovia Professor at the Biozentrum and the Swiss Nanoscience Institute of the University of Basel, has not only directly...
If a person pushes a broken-down car alone, there is a certain effect. If another person helps, the result is the sum of their efforts. If two micro-particles are pushing another microparticle, however, the resulting effect may not necessarily be the sum their efforts. A recent study published in Nature Communications, measured this odd effect that scientists call “many body.”
In the microscopic world, where the modern miniaturized machines at the new frontiers of technology operate, as long as we are in the presence of two...
Researchers from the Max Planck Institute Stuttgart have developed self-propelled tiny ‘microbots’ that can remove lead or organic pollution from contaminated water.
Working with colleagues in Barcelona and Singapore, Samuel Sánchez’s group used graphene oxide to make their microscale motors, which are able to adsorb lead...
Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.
In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...
Honeycomb structures as the basic building block for industrial applications presented using holo pyramid
Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...
27.04.2016 | Event News
15.04.2016 | Event News
12.04.2016 | Event News
04.05.2016 | Physics and Astronomy
04.05.2016 | Physics and Astronomy
04.05.2016 | Materials Sciences