Tag Archives: European Research Council (ERC)

The how and why of nanopores

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An August 19, 2021 Universidade NOVA de Lisboa ITQB NOVA press release (also on EurekAlert) explains what nanopores are while describing research into determining how their locations can be controlled,

At the simplest of levels, nanopores are (nanometre-sized) holes in an insulating membrane. The hole allows ions to pass through the membrane when a voltage is applied, resulting in a measurable current. When a molecule passes through a nanopore it causes a change in the current, this can be used to characterize and even identify individual molecules. Nanopores are extremely powerful single-molecule biosensing devices and can be used to detect and sequence DNA, RNA, and even proteins. Recently, it has been used in the SARS-CoV-2 virus sequencing.  

Solid-state nanopores are an extremely versatile type of nanopore formed in ultrathin membranes (less than 50 nanometres), made from materials such as silicon nitride (SiNx). Solid-state nanopores can be created with a range of diameters and can withstand a multitude of conditions (discover more about solid-state nanopore fabrication techniques here). One of the most appealing techniques with which to fabricate nanopores is Controlled Breakdown (CBD). This technique is quick, reduces fabrication costs, does not require specialized equipment, and can be automated.

CBD is a technique in which an electric field is applied across the membrane to induce a current. At some point, a spike in the current is observed, signifying pore formation. The voltage is then quickly reduced to ensure the fabrication of a single, small nanopore.

The mechanisms underlying this process have not been fully elucidated thus an international team involving ITQB NOVA decided to further investigate how electrical conduction through the membrane occurs during breakdown, namely how oxidation and reduction reactions (also called redox reactions, they imply electron loss or gain, respectively) influence the process. To do this, the team created three devices in which the electric field is applied to the membrane (a silicon-rich SiNx membrane) in different ways: via metal electrodes on both sides of the membrane; via electrolyte solutions on both sides of the membrane; and via a mixed device with a metal electrode on one side and an electrolyte solution on the other.

Results showed that redox reactions must occur at the membrane-electrolyte interface, whilst the metal electrodes circumvent this need. The team also demonstrated that, because of this phenomenon, nanopore fabrication could be localized to certain regions by performing CBD with metal microelectrodes on the membrane surface. Finally, by varying the content of silicon in the membrane, the investigators demonstrated that conduction and nanopore formation is highly dependent on the membrane material since it limits the electrical current in the membrane.

“Controlling the location of nanopores has been of interest to us for a number of years”, says James Yates. Pedro Sousa adds that “our findings suggest that CBD can be used to integrate pores with complementary micro or nanostructures, such as tunneling electrodes or field-effect sensors, across a range of different membrane materials.”  These devices may then be used for the detection of specific molecules, such as proteins, DNA, or antibodies, and applied to a wide array of scenarios, including pandemic surveillance or food safety.

This project was developed by a research team led by ITQB NOVA’s James Yates and has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No 724300 and 875525). Co-author Pedro Miguel Sousa is also from ITQB NOVA. The other consortium members are from the University of Oxford, Oak Ridge National Laboratory, Imperial College London and Queen Mary University of London. The authors would like to thank Andrew Briggs for providing financial support.

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

Understanding Electrical Conduction and Nanopore Formation During Controlled Breakdown by Jasper P. Fried, Jacob L. Swett, Binoy Paulose Nadappuram, Aleksandra Fedosyuk, Pedro Miguel Sousa, Dayrl P. Briggs, Aleksandar P. Ivanov, Joshua B. Edel, Jan A. Mol, James R. Yates. Small DOI: https://doi.org/10.1002/smll.202102543 First published: 01 August 2021

This paper is open access.

Skin as a touchscreen (“smart” hands)

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An April 11, 2016 news item on phys.org highlights some research presented at the IEEE (Institute of Electrical and Electronics Engineers) Haptics (touch) Symposium 2016,

Using your skin as a touchscreen has been brought a step closer after UK scientists successfully created tactile sensations on the palm using ultrasound sent through the hand.

The University of Sussex-led study – funded by the Nokia Research Centre and the European Research Council – is the first to find a way for users to feel what they are doing when interacting with displays projected on their hand.

This solves one of the biggest challenges for technology companies who see the human body, particularly the hand, as the ideal display extension for the next generation of smartwatches and other smart devices.

Current ideas rely on vibrations or pins, which both need contact with the palm to work, interrupting the display.

However, this new innovation, called SkinHaptics, sends sensations to the palm from the other side of the hand, leaving the palm free to display the screen.

An April 11, 2016 University of Sussex press release (also on EurekAlert) by James Hakmer, which originated the news item, provides more detail,

The device uses ‘time-reversal’ processing to send ultrasound waves through the hand. This technique is effectively like ripples in water but in reverse – the waves become more targeted as they travel through the hand, ending at a precise point on the palm.

It draws on a rapidly growing field of technology called haptics, which is the science of applying touch sensation and control to interaction with computers and technology.

Professor Sriram Subramanian, who leads the research team at the University of Sussex, says that technologies will inevitably need to engage other senses, such as touch, as we enter what designers are calling an ‘eye-free’ age of technology.

He says: “Wearables are already big business and will only get bigger. But as we wear technology more, it gets smaller and we look at it less, and therefore multisensory capabilities become much more important.

“If you imagine you are on your bike and want to change the volume control on your smartwatch, the interaction space on the watch is very small. So companies are looking at how to extend this space to the hand of the user.

“What we offer people is the ability to feel their actions when they are interacting with the hand.”

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The findings were presented at the IEEE Haptics Symposium [April 8 – 11] 2016 in Philadelphia, USA, by the study’s co-author Dr Daniel Spelmezan, a research assistant in the Interact Lab.

There is a video of the work (I was not able to activate sound, if there is any accompanying this video),

The consequence of watching this silent video was that I found the whole thing somewhat mysterious.

Revolutionary ‘smart’ windows from the UK

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This is the first time I’ve seen self-cleaning and temperature control features mentioned together with regard to a ‘smart’ window, which makes this very exciting news. From a Jan. 20, 2016 UK Engineering and Physical Sciences Research Council (EPSRC) press release (also on EurekAlert),

A revolutionary new type of smart window could cut window-cleaning costs in tall buildings while reducing heating bills and boosting worker productivity. Developed by University College London (UCL) with support from EPSRC, prototype samples confirm that the glass can deliver three key benefits:

Self-cleaning: The window is ultra-resistant to water, so rain hitting the outside forms spherical droplets that roll easily over the surface – picking up dirt, dust and other contaminants and carrying them away. This is due to the pencil-like, conical design of nanostructures engraved onto the glass, trapping air and ensuring only a tiny amount of water comes into contact with the surface. This is different from normal glass, where raindrops cling to the surface, slide down more slowly and leave marks behind.
Energy-saving: The glass is coated with a very thin (5-10nm) film of vanadium dioxide which during cold periods stops thermal radiation escaping and so prevents heat loss; during hot periods it prevents infrared radiation from the sun entering the building. Vanadium dioxide is a cheap and abundant material, combining with the thinness of the coating to offer real cost and sustainability advantages over silver/gold-based and other coatings used by current energy-saving windows.
Anti-glare: The design of the nanostructures also gives the windows the same anti-reflective properties found in the eyes of moths and other creatures that have evolved to hide from predators. It cuts the amount of light reflected internally in a room to less than 5 per cent – compared with the 20-30 per cent achieved by other prototype vanadium dioxide coated, energy-saving windows – with this reduction in ‘glare’ providing a big boost to occupant comfort.

This is the first time that a nanostructure has been combined with a thermochromic coating. The bio-inspired nanostructure amplifies the thermochromics properties of the coating and the net result is a self-cleaning, highly performing smart window, said Dr Ioannis Papakonstantinou of UCL.

The UCL team calculate that the windows could result in a reduction in heating bills of up to 40 per cent, with the precise amount in any particular case depending on the exact latitude of the building where they are incorporated. Windows made of the ground-breaking glass could be especially well-suited to use in high-rise office buildings.

Dr Ioannis Papakonstantinou of UCL, project leader, explains: It’s currently estimated that, because of the obvious difficulties involved, the cost of cleaning a skyscraper’s windows in its first 5 years is the same as the original cost of installing them. Our glass could drastically cut this expenditure, quite apart from the appeal of lower energy bills and improved occupant productivity thanks to less glare. As the trend in architecture continues towards the inclusion of more glass, it’s vital that windows are as low-maintenance as possible.

So, when can I buy these windows? (from the press release; Note: Links have been removed)

Discussions are now under way with UK glass manufacturers with a view to driving this new window concept towards commercialisation. The key is to develop ways of scaling up the nano-manufacturing methods that the UCL team have specially developed to produce the glass, as well as scaling up the vanadium dioxide coating process. Smart windows could begin to reach the market within around 3-5 years [emphasis mine], depending on the team’s success in securing industrial interest.

Dr Papakonstantinou says: We also hope to develop a ‘smart’ film that incorporates our nanostructures and can easily be added to conventional domestic, office, factory and other windows on a DIY [do-it-yourself] basis to deliver the triple benefit of lower energy use, less light reflection and self-cleaning, without significantly affecting aesthetics.

Professor Philip Nelson, Chief Executive of EPSRC said: This project is an example of how investing in excellent research drives innovation to produce tangible benefits. In this case the new technique could deliver both energy savings and cost reductions.

A 5-year European Research Council (ERC) starting grant (IntelGlazing) has been awarded to fabricate smart windows on a large scale and test them under realistic, outdoor environmental conditions.

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The UCL team that developed the prototype smart window includes Mr Alaric Taylor, a PhD student in Dr Papakonstantinou’s group, and Professor Ivan Parkin from UCL’s Department of Chemistry.

I wish them good luck.

One last note, these new windows are the outcome of a 2.5 year EPSRC funded project: Biologically Inspired Nanostructures for Smart Windows with Antireflection and Self-Cleaning Properties, which ended in Sept.  2015.

Investigating how magnons, also called magnetic spin waves, could improve computer speed and performance

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This is a story about funding for a young scientist, from a Nov. 29, 2015 news item on Nanotechnology Now,

Young scientist Dr Andrii Chumak conducts research about the fundamental physics of next-generation data processing. His approach is based on magnons, also called magnetic spin waves, that hold the potential for significant improvements in the speed and performance of computers. At the University of Kaiserslautern’s State Research Center OPTIMAS, Chumak investigates how spin waves can be excited and manipulated in circuits smaller than one ten-thousandth of a millimetre. For this, he is now to receive a particularly prestigious package of financial support amounting to 1.5 million euros. The funding, which he will invest in his research over a period of five years, is being awarded by the European Research Council (ERC). Only a number of approx. 330 of these so-called “Starting Grants” are awarded across the whole of Europe – and across all scientific disciplines.

A Nov. 25, 2015 University of Kaiserslautern press release, which originated the news item, describes the problem  Dr. Andrii Chumak is trying to solve and his proposed solution,

Efforts to make electronic circuits ever smaller and faster are hampered by physical boundaries. For example, it becomes increasingly difficult to dissipate the heat generated by computing from the tiny structures. This is where Dr Chumak’s research comes into play. The physicist has suggested using a special type of spin waves that take up extremely little space and do quickly propagate. So far, these so-called exchange spin waves have only been scarcely studied. Therefore, Chumak and his team plan to investigate close to practical conditions how magnons of this kind can be produced and manipulated in solids, and how they interact with each other. “We want to develop a toolbox for producing magnonic conductors with a size of less than 100 nanometres,” says the Ukrainian researcher, who has been living in Kaiserslautern for seven years. “To do this, however, you first have to better understand the underlying physical phenomena, which are often quite exotic on such tiny scales.” The ultimate aim is to develop practical nano-circuits combining two important elements of magnonic data processing, namely magnonic transistors and majority gates. Both of these concepts have already been described for a different type of spin waves. Now, Dr Andrii Chumak hopes to show that these too can be miniaturised.

Waves instead of friction

The reason why computer chips heat up is that the electrons flowing through the material create a sort of friction. Magnonics offers a very promising opportunity to overcome this and other problems for higher-performance hardware. Instead of electrons, it is possible to make use of magnetic phenomena caused by the spin (the electrons’ intrinsic angular momentum). These immaterial waves of spins are referred to as magnons. “Waves can transport more information than particles,” says Andrii Chumak. “This opens up completely new possibilities for making computers even faster and more powerful.” However, magnonic components must also be very, very tiny if they are to stand any chance of competing with the semiconductor technology that is commonplace today. Current experimental designs are still occupying the millimetre scale – far too big to be installed in competitive chips.

Andrii Chumak’s career

The 33-year-old physicist had already started working on magnetic spin waves during his doctoral thesis at the University of Kiev. This work, carried out under the supervision of Professor Gennadii A. Melkov, was initially limited to fundamental research. In 2008, Chumak came to the University of Kaiserslautern, where he became a group leader in Professor Burkard Hillebrands’ team. In his current experiments, Chumak has increasingly turned his attention to application-oriented fundamental research. As a science-fiction fan, he is constantly amazed at how real-life technological development is overtaking any imagination: “Although all kinds of things have been predicted, such as the Mars landing, nuclear batteries or antigravity, I’ve never met anyone who guessed that, today, we’d have smartphones providing access to the world’s entire knowledge in our trouser pockets, as well as allowing us to make phone calls, watch TV, navigate and perform calculations.”

It’s nice to see that sometimes even scientists are overcome with the latest advances.