Tag Archives: Andrey Miroshnichenko

Materials that may protect astronauts from radiation in space

Sparing astronauts from harmful radiation  is one of the goals for this project according to a July 3, 2017 news item on Nanowerk (Note: A link has been removed),

Scientists at The Australian National University (ANU) have designed a new nano material that can reflect or transmit light on demand with temperature control, opening the door to technology that protects astronauts in space from harmful radiation (Advanced Functional Materials, “Reversible Thermal Tuning of All-Dielectric Metasurfaces”).

Lead researcher Dr Mohsen Rahmani from ANU said the material was so thin that hundreds of layers could fit on the tip of a needle and could be applied to any surface, including spacesuits.

The first speaker’s enthusiasm leaps off the screen,

For whose who prefer to read their news, a July 4, 2017 ANU press release, which originated the news item, provides more detail,

“Our invention has a lot of potential applications, such as protecting astronauts or satellites with an ultra-thin film that can be adjusted to reflect various dangerous ultraviolet or infrared radiation in different environments,” said Dr Rahmani, an Australian Research Council (ARC) Discovery Early Career Research Fellow at the Nonlinear Physics Centre within the ANU Research School of Physics and Engineering.

“Our technology significantly increases the resistance threshold against harmful radiation compared to today’s technologies, which rely on absorbing radiation with thick filters.”

Co-researcher Associate Professor Andrey Miroshnichenko said the invention could be tailored for other light spectrums including visible light, which opened up a whole array of innovations, including architectural and energy saving applications.

“For instance, you could have a window that can turn into a mirror in a bathroom on demand, or control the amount of light passing through your house windows in different seasons,” said Dr Miroshnichenko from the Nonlinear Physics Centre within the ANU Research School of Physics and Engineering.

“What I love about this invention is that the design involved different research disciplines including physics, materials science and engineering.”

Co-lead researcher Dr Lei Xu said achieving cost-efficient and confined temperature control such as local heating was feasible.

“Much like your car has a series of parallel resistive wires on the back windscreen to defog the rear view, a similar arrangement could be used with our invention to confine the temperature control to a precise location,” said Dr Xu from the Nonlinear Physics Centre within the ANU Research School of Physics and Engineering.

The innovation builds on more than 15 years of research supported by the ARC through CUDOS, a Centre of Excellence, and the Australian National Fabrication Facility.

Here’s a link to and a citation for the paper,

Reversible Thermal Tuning of All-Dielectric Metasurfaces by Mohsen Rahmani, Lei Xu, Andrey E. Miroshnichenko, Andrei Komar, Rocio Camacho-Morales, Haitao Chen, Yair Zárate, Sergey Kruk, Guoquan Zhang, Dragomir N. Neshev, and Yuri S. Kivshar. Advanced Functional Materials DOI: 10.1002/adfm.201700580 Version of Record online: 3 JUL 2017

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Building architecture inspires new light-bending material

Usually, it’s nature which inspires scientists but not this time. Instead, a building in Canberra, Australia has provided the inspiration according to a March 24, 2015 news item on Nanowerk,

Physicists inspired by the radical shape of a Canberra building have created a new type of material which enables scientists to put a perfect bend in light.

The creation of a so-called topological insulator could transform the telecommunications industry’s drive to build an improved computer chip using light.

Leader of the team, Professor Yuri Kivshar from The Australian National University (ANU) said the revolutionary material might also be useful in microscopes, antenna design, and even quantum computers.

“There has been a hunt for similar materials in photonics based on large complicated structures,” said Professor Kivshar, who is the head of the Nonlinear Physics Centre in ANU Research School of Physics and Engineering.

“Instead we used a simple, small-scale zigzag structure to create a prototype of these novel materials with amazing properties.”

The structure was inspired by the Nishi building near ANU, which consists of rows of offset zigzag walls.

Here’s what the building looks like,

Caption: Alex Slobozhanyuk (L) and Andrey Miroshnichenko with models of their material structures in front of the Nishi building that inspired them. Credit: Stuart Hay, ANU

Caption: Alex Slobozhanyuk (L) and Andrey Miroshnichenko with models of their material structures in front of the Nishi building that inspired them.
Credit: Stuart Hay, ANU

A March 24, 2015 Australian National University press release, which originated the news item, goes on to describe topological insulators and what makes this ‘zigzag’ approach so exciting,

Topological insulators have been initially developed for electronics, and the possibility of building an optical counterpart is attracting a lot of attention.

The original zigzag structure of the material was suggested in the team’s earlier collaboration with Dr Alexander Poddubny, from Ioffe Institute in Russia, said PhD student Alexey Slobozhanyuk.

“The zigzag structure creates a coupling throughout the material that prevents light from travelling through its centre,” Mr Slobozhanyuk said.

“Instead light is channelled to the edges of the material, where it becomes completely localised by means of a kind of quantum entanglement known as topological order.”

Fellow researcher Dr Andrew Miroshnichenko said the building inspired the researchers to think of multiple zigzags.

“We had been searching for a new topology and one day I looked at the building and a bell went off in my brain,” said fellow researcher Dr Andrey Miroshnichenko.

“On the edges of such a material the light should travel completely unhindered, surfing around irregularities that would normally scatter the light.

“These materials will allow light to be bent around corners with no loss of signal,” he said.

The team showed that the exceptional attributes of the material are related to its structure, or topology, and not to the molecules it is made from.

“In our experiment we used an array of ceramic spheres, although the initial theoretical model used metallic subwavelength particles,” said Dr Miroshnichenko.

“Even though they are very different materials they gave the same result.”

In contrast with other international groups attempting to create topological insulators with large scale structures, the team used spheres that were smaller than the wavelength of the microwaves in their successful experiments.

Dr Poddubny devised the theory when he realised there was a direct analogy between quantum Kitaev’s model of Majorana fermions and optically coupled subwavelength scatterers.

Mr Slobozhanyuk said the team could control which parts of the material surface the light is channelled to by changing the polarisation of the light.

“This opens possibilities ranging from nanoscale light sources for enhancing microscopes, highly efficient antennas or even quantum computing,” he said.

“The structure couples the two sides of the material, so they could be used as entangled qubits for quantum computing.”

It would be nice to offer a link to a published paper but I cannot find one.