Tag Archives: Imperial College London

Donna Strickland, first female Nobel Prize winner in 55 years and one of only three (so far) in history

It’s been quite the fascinating week in the world of physics culminating with Donna Strickland’s shiny new Nobel Prize in physics.

For my purposes, this week in physics started on Friday, September 28, 2018 with Allesanndro Strumia’s presentation at CERN’s (European Particle Physics Laboratory) “1st workshop on high energy theory and gender” where he claimed and proved ‘scientifically’ that physics has become “sexist against men.” I’ll get back to Strumia in a moment but, first, let’s celebrate Donna Strickland and her achievements.

Only three women, including Strickland, in the history (117 years) of the Nobel Prize for Physics have won it, Marie Curie in 1903, Maria Goeppert Mayer in 1963, and, now, Strickland in 2018.

The University of Waterloo (Ontario, Canada) had this to say in an October 2, 2018 news release,

Donna Strickland wins Nobel Prize in Physics

Tuesday, October 2, 2018

Dr. Donna Strickland

Donna Strickland, a University of Waterloo professor who helped revolutionize laser physics, has been named a winner of this year’s Nobel Prize in Physics.

Strickland, an associate professor in the Department of Physics and Astronomy, shares half the $1.4 million prize with French laser physicist Gérard Mourou. The other half was awarded to U.S. physicist Arthur Ashkin.

The Royal Swedish Academy of Sciences stated that Mourou and Strickland paved the way toward the shortest and most intense laser pulses created by mankind. Their revolutionary article was published in 1985 and was the foundation of Strickland’s doctoral thesis.

Strickand conducted her Nobel-winning research while a PhD student under Mourou in 1989 at the University of Rochester in New York. The team’s research has a number of applications in industry and medicine.

It was great to have had the opportunity to work with one of the pioneers of ultrafast lasers, Gerard Mourou,” said Strickland. “It was a small community back then. It was a new, burgeoning field. I got to be part of that. It was very exciting.”

A Nobel committee member said billions of people make daily use of laser printers and optical scanners and millions undergo laser surgery.

“This is a tremendous day for Professor Strickland and needless to say a tremendous day for the University of Waterloo,” said Feridun Hamdullahpur, president and vice-chancellor of the University of Waterloo. “This is Waterloo’s first Nobel laureate and the first woman to receive the Nobel Prize in Physics in 55 years.”

During an interview, Strickland told the Globe and Mail [national newspaper]: “We need to celebrate women physicists because we’re out there, and hopefully in time it’ll start to move forward at a faster rate.”

Charmaine Dean, vice-president research at the University of Waterloo said: “Donna Strickland exemplifies research excellence at Waterloo. Her groundbreaking work is a testament to the importance of fundamental research as it has established the foundation for laser-based technologies that we see today from micromachining to laser eye surgery.”

An October 2, 2018 news item on Nanowerk focuses on the three winners,

Arthur Ashkin, an American physicist has been awarded half the prize for his invention of optical tweezers and their application to biological systems. His amazing tool has helped to reach the old dream of grabing [sic] particles, atoms, viruses and other living cells. The optical tweezers work with the radiation pressure of light to hold and move tiny object and are widely used to study the machinery of life.

French physicist Gérard Mourou and Canadian physicist Donna Strickland share the other half for their method of generating ultra-short and very intense optical pulses. Ultra-sharp laser beams have made possible to cut or drill holes in various materials extremely precisely – even in living matter. The technique this duo pioneered is called chirped pulse amplification or CPA and it has led to corrective eye surgeries for millions of people.

An Oct. 2, 2018 article by Marina Koren for The Atlantic is my favourite of the ones focusing on Strickland. One of Koren’s major focal points is Strickland’s new Wikipedia page (Note: Links have been removed),

It was about five in the morning in Ontario, Canada, when Donna Strickland’s phone rang. The Nobel Prize committee was on the line in Stockholm, calling to tell her she had won the prize in physics.

“We wondered if it was a prank,” Strickland said Tuesday [October 2 ,2018], in an interview with a Nobel official after the call. She had been asleep when the call arrived. “But then I knew it was the right day, and it would have been a cruel prank.”

Lasers, focused beams of light particles, were invented in the 1960s. Scientists immediately started tinkering with them, looking for ways to harness and manipulate these powerful devices.

Strickland and [Gérard] Mourou] found a way to stretch and compress lasers to produce short, intense pulses that are now used, among other things, in delicate surgeries to fix vision problems. [Arthur] Ashkin figured out a way to maneuver laser light so that it could push small particles toward the center of the beam, hold them in place, and even move them around. This technique became the delightfully named “optical tweezer.” It allowed Ashkin to use the power of light to capture and hold living bacteria and viruses without harming the organisms.

Unlike her fellow winners, Strickland did not have a Wikipedia page at the time of the announcement. A Wikipedia user tried to set up a page in May, but it was denied by a moderator with the message: “This submission’s references do not show that the subject qualifies for a Wikipedia article.” Strickland, it was determined, had not received enough dedicated coverage elsewhere on the internet to warrant a page.

On Tuesday, a newly created page flooded with edits: “Added in her title.” “Add Nobel-winning paper.” “Added names of other women Nobelists [sic] in physics.”

The construction of the Wikipedia page feels like a metaphor for a historic award process that has long been criticized for neglecting women in its selection, and for the shortage of women’s stories in the sciences at large. To scroll through the “history” tab of Strickland’s page, where all edits are recorded and tracked, is to witness in real time the recognition of a scientist whose story likely deserved attention long before the Nobel Prize committee called.

Strickland’s historic win comes a day after CERN, the European organization that operates the world’s most powerful particle accelerator, suspended a senior scientist for saying that physics was “invented and built by men.” Alessandro Strumia, a professor at the University of Pisa, made the statement during a recent speech at a seminar on gender issues in physics that was attended by mostly female physicists. Strumia said “men prefer working with things and women prefer working with people,” and that between men and women there is a “difference even in children before any social influence.” His remarks were widely circulated online and prompted fierce backlash.

The remarks don’t faze Strickland, who very publicly proved them wrong on Tuesday. In an interview with the BBC on Tuesday, she called Strumia’s claims “silly.”

For anyone curious about the Strumia situation, there’s an October 2, 2018 CBC Radio (As It Happens) online news article. Note: Links have been removed,

Not only was Alessandro Strumia being offensive when he said that physics “was invented and built by men” — he was also wrong, says physicist Jess Wade.

“Actually, women have contributed hugely to physics throughout the whole of history, but for an incredibly long time we haven’t documented or told those stories,” Wade told As It Happens host Carol Off.

And she would know. The Imperial College London research associate has made it her mission to write hundreds of Wikipedia entries about women in science and engineering.

Wade was in the room on Friday when Strumia, a physicist at Pisa University, made the inflammatory remarks during a gender workshop in Geneva, organized by the European nuclear research centre CERN.

CERN cut ties with Strumia after the BBC reported the content of his presentation.

This article includes some of the slides in Strumia’s now infamous presentation.

Tommaso Dorigo in an October 1, 2018 posting on the Science 2.0 blog offers another analysis,

The world of particle physics is in turmoil because of a presentation by Alessandro Strumia, an Italian phenomenologist, at CERN’s “1st workshop on high energy theory and gender”, and its aftermath.

By now the story has been echoed by many major newscasters around the world, and discussed in public and private forums, blogs, twitter feeds. I wanted to stay away from it here, mainly because it is a sensitive issue and the situation is still evolving, but after all, why not offer to you my personal pitch on the matter? Strumia, by the way, has been an occasional commenter to this blog – you can find some of his comments signed as “AS” in threads of past articles. Usually he makes good points here, as long as physics is the subject.

Anyway, first of all let me give you a quick recall of the events. The three-day workshop, which took place on September 26-28, was meant to”focus on recent developments in theoretical high-energy physics and cosmology, and discuss issues of gender and equal opportunities in the field“; it followed three previous events which combined string theory and gender issues. Strumia’s presentation was titled “Experimental tests of a new global symmetry“, a physicist’s way of describing the issue of man-woman equality. It is important to note that the talk was not an invited one – its author had asked the organizers for a slot as he said he would be talking of bibliometrics, and indeed his contribution was listed in the agenda of September 28 with the innocuous title “Bibliometrics data about gender issues in fundamental theory“.

Strumia’s slides contain a collection of half-baked claims, coming from his analysis of InSpire data from citations and authorship of articles in theoretical physics. I consider his talk offensive on many levels. It starts by casting the woman discrimination issue in scientific academia as a test of hypothesis of whether the “man-woman” symmetry is explicitly broken (i.e. there is no symmetry) or spontaneously broken (by a difference of treatment) – something that could even raise a smile in a geeky physicist; but the fun ends there.

Dorigo offers a detailed ‘takedown’ of Strumia’s assertions. I found the post intriguing for the insight it offers into physics. Never in a million years would I have thought this title, “Experimental tests of a new global symmetry,” would indicate a discussion on gender balance in the field of physics.

As I said in the opening, it has been quite the week in physics. On a final note, Brava to Doctor Donna Strickland!

Tractor beams for artificial cells

This particular piece has videos of cells moving around. I won’t be including all of them but they are weirdly fascinating. First, a May 14, 2018 news item on Nanowerk announces the latest in tractor beam news from the Imperial College London (ICL; UK),

Researchers have used lasers to connect, arrange and merge artificial cells, paving the way for networks of artificial cells that act like tissues.

The team say that by altering artificial cell membranes they can now get the cells to stick together like ‘stickle bricks’ – allowing them to be arranged into whole new structures.

Biological cells can perform complex functions, but are difficult to controllably engineer.

Artificial cells, however, can in principle be made to order. Now, researchers from Imperial College London and Loughborough University have demonstrated a new level of complexity with artificial cells by arranging them into basic tissue structures with different types of connectivity.

These structures could be used to perform functions like initiating chemical reactions or moving chemicals around networks of artificial and biological cells. This could be useful in carrying out chemical reactions in ultra-small volumes, in studying the mechanisms through which cells communicate with one another, and in the development of a new generation of smart biomaterials.

A May 14, 2018 ICL press release by Hayley Dunning , which originated the news item, provides more detail,

Cells are the basic units of biology, which are capable of working together as a collective when arranged into tissues. In order to do this, cells must be connected and be capable of exchanging materials with one another.

The team were able to link up artificial cells into a range of new architectures, the results of which are published today in Nature Communications.

The artificial cells have a membrane-like layer as their shell, which the researchers engineered to ‘stick’ to each other. In order to get the cells to come close enough, the team first had to manipulate the cells with ‘optical tweezers’ that act like mini ‘tractor beams’ dragging and dropping cells into any position. Once connected in this way the cells can be moved as one unit.

Lead researcher Dr Yuval Elani, an EPSRC Research Fellow from the Department of Chemistry at Imperial, said: “Artificial cell membranes usually bounce off each other like rubber balls. By altering the biophysics of the membranes in our cells, we got them instead to stick to each other like stickle bricks.

“With this, we were able to form networks of cells connected by ‘biojunctions’. By reinserting biological components such as proteins in the membrane, we could get the cells to communicate and exchange material with one another. This mimics what is seen in nature, so it’s a great step forward in creating biological-like artificial cell tissues.”

Building up complexity

The team were also able to engineer a ‘tether’ between two cells. Here the membranes are not stuck together, but a tendril of membrane material links them so that they can be moved together.

Once they had perfected the cell-sticking process, the team were able to build up more complex arrangements. These include lines of cells, 2D shapes like squares, and 3D shapes like pyramids. Once the cells are stuck together, they can be rearranged, and also pulled by the laser beam as an ensemble

Finally, the team were also able to connect two cells, and then make them merge into one larger cell. This was achieved by coating the membranes with gold nanoparticles.

When the laser beam at the heart of the ‘optical tweezer’ technology was concentrated at the junction between the two cells, the nanoparticles resonated, breaking the membranes at that point. The membrane then reforms as a whole.

Merging cells in this way allowed whatever chemicals they were carrying to mix within the new, larger cell, kicking off chemical reactions. This could be useful, for example, for delivering materials such as drugs into cells, and in changing the composition of cells in real time, getting them to adopt new functions.

Professor Oscar Ces, also from the Department of Chemistry at Imperial, said: “Connecting artificial cells together is a valuable technology in the wider toolkit we are assembling for creating these biological systems using bottom-up approaches.

“We can now start to scale up basic cell technologies into larger tissue-scale networks, with precise control over the kind of architecture we create.”

Here’s one of the videos that has been embedded with ICL press release,

You can see the whole series if you go to the May 14, 2018 ICL press release.

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

Sculpting and fusing biomimetic vesicle networks using optical tweezers by Guido Bolognesi, Mark S. Friddin, Ali Salehi-Reyhani, Nathan E. Barlow, Nicholas J. Brooks, Oscar Ces, & Yuval Elani. Nature Communicationsvolume 9, Article number: 1882 (2018) doi:10.1038/s41467-018-04282-w Published: 14 May 2018

This paper is open access.

Edible water bottles by Ooho!

Courtesy: Skipping Rocks Lab

As far as I’m concerned, that looks more like a breast implant than a water bottle, which, from a psycho-social perspective, could lead to some interesting research papers. It is, in fact a new type of water bottle.  From an April 10, 2017 article by Adele Peters for Fast Company (Note: Links have been removed),

If you run in a race in London in the near future and pass a hydration station, you may be handed a small, bubble-like sphere of water instead of a bottle. The gelatinous packaging, called the Ooho, is compostable–or even edible, if you want to swallow it. And after two years of development, its designers are ready to bring it to market.

Three London-based design students first created a prototype of the edible bottle in 2014 as an alternative to plastic bottles. The idea gained internet hype (though also some scorn for a hilarious video that made the early prototypes look fairly impossible to use without soaking yourself).
The problem it was designed to solve–the number of disposable bottles in landfills–keeps growing. In the U.K. alone, around 16 million are trashed each day; another 19 million are recycled, but still have the environmental footprint of a product made from oil. In the U.S., recycling rates are even lower. …

The new packaging is based on the culinary technique of spherification, which is also used to make fake caviar and the tiny juice balls added to boba tea [bubble tea?]. Dip a ball of ice in calcium chloride and brown algae extract, and you can form a spherical membrane that keeps holding the ice as it melts and returns to room temperature.

An April 25, 2014 article by Kashmira Gander for Independent.co.uk describes the technology and some of the problems that had to be solved before bringing this product to market,

To make the bottle [Ooho!], students at the Imperial College London gave a frozen ball of water a gelatinous layer by dipping it into a calcium chloride solution.

They then soaked the ball in another solution made from brown algae extract to encapsulate the ice in a second membrane, and reinforce the structure.

However, Ooho still has teething problems, as the membrane is only as thick as a fruit skin, and therefore makes transporting the object more difficult than a regular bottle of water.

“This is a problem we’re trying to address with a double container,” Rodrigo García González, who created Ooho with fellow students Pierre Paslier and Guillaume Couche, explained to the Smithsonian. “The idea is that we can pack several individual edible Oohos into a bigger Ooho container [to make] a thicker and more resistant membrane.”

According to Peters’ Fast Company article, the issues have been resolved,

Because the membrane is made from food ingredients, you can eat it instead of throwing it away. The Jell-O-like packaging doesn’t have a natural taste, but it’s possible to add flavors to make it more appetizing.

The package doesn’t have to be eaten every time, since it’s also compostable. “When people try it for the first time, they want to eat it because it’s part of the experience,” says Pierre Paslier, cofounder of Skipping Rocks Lab, the startup developing the packaging. “Then it will be just like the peel of a fruit. You’re not expected to eat the peel of your orange or banana. We are trying to follow the example set by nature for packaging.”

The outer layer of the package is always meant to be peeled like fruit–one thin outer layer of the membrane peels away to keep the inner layer clean and can then be composted. (While compostable cups are an alternative solution, many can only be composted in industrial facilities; the Ooho can be tossed on a simple home compost pile, where it will decompose within weeks).

The company is targeting both outdoor events and cafes. “Where we see a lot of potential for Ooho is outdoor events–festivals, marathons, places where basically there are a lot of people consuming packaging over a very short amount of time,” says Paslier.

I encourage you to read Peters’ article in its entirety if you have the time. You can also find more information on the Skipping Rocks Lab website and on the company’s crowdfunding campaign on CrowdCube.

New form of light could lead to circuits that run on photons instead of electrons

If circuits are running on photons instead of electrons, does that mean there will be no more electricity and electronics?  Apparently, the answer is not exactly. First, an Aug. 5, 2016 news item on ScienceDaily makes the announcement about photons and circuits,

New research suggests that it is possible to create a new form of light by binding light to a single electron, combining the properties of both.

According to the scientists behind the study, from Imperial College London, the coupled light and electron would have properties that could lead to circuits that work with packages of light — photons — instead of electrons.

It would also allow researchers to study quantum physical phenomena, which govern particles smaller than atoms, on a visible scale.

An Aug. 5, 2016 Imperial College of London (ICL) press release, which originated the news item, describes the research further (Note: A link has been removed),

In normal materials, light interacts with a whole host of electrons present on the surface and within the material. But by using theoretical physics to model the behaviour of light and a recently-discovered class of materials known as topological insulators, Imperial researchers have found that it could interact with just one electron on the surface.

This would create a coupling that merges some of the properties of the light and the electron. Normally, light travels in a straight line, but when bound to the electron it would instead follow its path, tracing the surface of the material.

Improved electronics

In the study, published today in Nature Communications, Dr Vincenzo Giannini and colleagues modelled this interaction around a nanoparticle – a small sphere below 0.00000001 metres in diameter – made of a topological insulator.

Their models showed that as well as the light taking the property of the electron and circulating the particle, the electron would also take on some of the properties of the light. [emphasis mine]

Normally, as electrons are travelling along materials, such as electrical circuits, they will stop when faced with a defect. However, Dr Giannini’s team discovered that even if there were imperfections in the surface of the nanoparticle, the electron would still be able to travel onwards with the aid of the light.

If this could be adapted into photonic circuits, they would be more robust and less vulnerable to disruption and physical imperfections.

Quantum experiments

Dr Giannini said: “The results of this research will have a huge impact on the way we conceive light. Topological insulators were only discovered in the last decade, but are already providing us with new phenomena to study and new ways to explore important concepts in physics.”

Dr Giannini added that it should be possible to observe the phenomena he has modelled in experiments using current technology, and the team is working with experimental physicists to make this a reality.

He believes that the process that leads to the creation of this new form of light could be scaled up so that the phenomena could observed much more easily.

Currently, quantum phenomena can only be seen when looking at very small objects or objects that have been super-cooled, but this could allow scientists to study these kinds of behaviour at room temperature.

An electron that takes on the properties of light? I find that fascinating.

Artistic image of light trapped on the surface of a nanoparticle topological insulator. Credit: Vincenzo Giannini

Artistic image of light trapped on the surface of a nanoparticle topological insulator. Credit: Vincenzo Giannini

For those who’d like more information, here’s a link to and a citation for the paper,

Single-electron induced surface plasmons on a topological nanoparticle by G. Siroki, D.K.K. Lee, P. D. Haynes,V. Giannini. Nature Communications 7, Article number: 12375  doi:10.1038/ncomms12375 Published 05 August 2016

This paper is open access.

Happy International Women’s Day March 8, 2016!

The UK’s Medical Research Council’s Clinical Science Centre and  Imperial College have found an interesting way to celebrate   International Women’s Day 2016 according to a March 8, 2016 posting by Stuart Clark for the Guardian (Note: Links have been removed),

Tonight [March 8, 2016] at the Royal Society, London, around a dozen women will be presented with Suffrage Science awards. Organised by the Medical Research Council’s Clinical Science Centre, Imperial College, they honour women’s contributions to science and are timing to coincide with International Women’s Day.

One of today’s awardees is Pippa Goldschmidt. She is being honoured for her work in science communication. With a PhD in astronomy, …

Her latest project is editing the short story collection I Am Because You Are. These stories all take their inspiration from Albert Einstein’s General Theory of Relativity, which is currently celebrating its 100th anniversary.

What can fiction bring to science?

Science is too often a closed book for many people, they study it at school and are bored by it, or find it difficult or irrelevant to their lives. But fiction has this incredible ability to reflect and examine all aspects of the real world, and writing fiction about science is a great way of opening it up to new audiences, and helping to demystify it.

Science is also heavily reliant on literary concepts, such as metaphors, to get its points across; we often hear the phrases ‘the Universe is like an expanding balloon’, or ‘DNA is like an alphabet’. So I think fiction and science have more in common with each other than may first appear.

Should you be able to attend, I’d be delighted to hear more about the event.

Next, I have a March 8, 2016 article by Lauren J. Young on Inverse.com (Note: Links have been removed),

Women have achieved a lot throughout history. That’s why today, on March 8, thousands of events are taking place in more than 40 countries across the world to celebrate International Women’s Day. This year’s theme is Planet 50-50 by 2030: Step it up for Gender Equality, alluding to the United Nations’ Sustainable Development Goals — a 15-year plan for growth and development in all countries including gender equality and education for all.

International Women’s Day dates back to February 28, 1909, when the Socialist Party of America observed it for the first time in the United States, and two years later, the leader of the Women’s Office for Germany’s Social Democratic Party, Clara Zetkin, expanded the idea internationally. It gained support by the United Nations in 1975, which strengthened the movement.

International Women’s Day is also a day to celebrate science: The United Nations created an interactive timeline documenting some of the most significant contributions made by women. Here are the three:

In Ancient Greece, Agnodice was one of the first female gynecologists. She risked her life to practice medicine even though women who were caught were sentenced to death.

You can find the UN timeline here.

Finally, the UN has a separate International Day of Women and Girls in Science celebrated on Feb. 11 (presumably of each year).

The evolution of molecules as observed with femtosecond stimulated Raman spectroscopy

A July 3, 2014 news item on Azonano features some recent research from the Université de Montréal (amongst other institutions),

Scientists don’t fully understand how ‘plastic’ solar panels work, which complicates the improvement of their cost efficiency, thereby blocking the wider use of the technology. However, researchers at the University of Montreal, the Science and Technology Facilities Council, Imperial College London and the University of Cyprus have determined how light beams excite the chemicals in solar panels, enabling them to produce charge.

A July 2, 2014 University of Montreal news release, which originated the news item, provides a fascinating description of the ultrafast laser process used to make the observations,

 “We used femtosecond stimulated Raman spectroscopy,” explained Tony Parker of the Science and Technology Facilities Council’s Central Laser Facility. “Femtosecond stimulated Raman spectroscopy is an advanced ultrafast laser technique that provides details on how chemical bonds change during extremely fast chemical reactions. The laser provides information on the vibration of the molecules as they interact with the pulses of laser light.” Extremely complicated calculations on these vibrations enabled the scientists to ascertain how the molecules were evolving. Firstly, they found that after the electron moves away from the positive centre, the rapid molecular rearrangement must be prompt and resemble the final products within around 300 femtoseconds (0.0000000000003 s). A femtosecond is a quadrillionth of a second – a femtosecond is to a second as a second is to 3.7 million years. This promptness and speed enhances and helps maintain charge separation.  Secondly, the researchers noted that any ongoing relaxation and molecular reorganisation processes following this initial charge separation, as visualised using the FSRS method, should be extremely small.

As for why the researchers’ curiosity was stimulated (from the news release),

The researchers have been investigating the fundamental beginnings of the reactions that take place that underpin solar energy conversion devices, studying the new brand of photovoltaic diodes that are based on blends of polymeric semiconductors and fullerene derivatives. Polymers are large molecules made up of many smaller molecules of the same kind – consisting of so-called ‘organic’ building blocks because they are composed of atoms that also compose molecules for life (carbon, nitrogen, sulphur). A fullerene is a molecule in the shape of a football, made of carbon. “In these and other devices, the absorption of light fuels the formation of an electron and a positive charged species. To ultimately provide electricity, these two attractive species must separate and the electron must move away. If the electron is not able to move away fast enough then the positive and negative charges simple recombine and effectively nothing changes. The overall efficiency of solar devices compares how much recombines and how much separates,” explained Sophia Hayes of the University of Cyprus, last author of the study.

… “Our findings open avenues for future research into understanding the differences between material systems that actually produce efficient solar cells and systems that should as efficient but in fact do not perform as well. A greater understanding of what works and what doesn’t will obviously enable better solar panels to be designed in the future,” said the University of Montreal’s Carlos Silva, who was senior author of the study.

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

Direct observation of ultrafast long-range charge separation at polymer–fullerene heterojunctions by Françoise Provencher, Nicolas Bérubé, Anthony W. Parker, Gregory M. Greetham, Michael Towrie, Christoph Hellmann, Michel Côté, Natalie Stingelin, Carlos Silva & Sophia C. Hayes. Nature Communications 5, Article number: 4288 doi:10.1038/ncomms5288 Published 01 July 2014

This article is behind a paywall but there is a free preview available vie ReadCube Access.

Controlling crystal growth for plastic electronics

A July 4, 2013 news item on Nanowerk highlights research into plastic electronics taking place at Imperial College London (ICL), Note: A link has been removed,

Scientists have discovered a way to better exploit a process that could revolutionise the way that electronic products are made.

The scientists from Imperial College London say improving the industrial process, which is called crystallisation, could revolutionise the way we produce electronic products, leading to advances across a whole range of fields; including reducing the cost and improving the design of plastic solar cells.

The process of making many well-known products from plastics involves controlling the way that microscopic crystals are formed within the material. By controlling the way that these crystals are grown engineers can determine the properties they want such as transparency and toughness. Controlling the growth of these crystals involves engineers adding small amounts of chemical additives to plastic formulations. This approach is used in making food boxes and other transparent plastic containers, but up until now it has not been used in the electronics industry.

The team from Imperial have now demonstrated that these additives can also be used to improve how an advanced type of flexible circuitry called plastic electronics is made.

The team found that when the additives were included in the formulation of plastic electronic circuitry they could be printed more reliably and over larger areas, which would reduce fabrication costs in the industry.

The team reported their findings this month in the journal Nature Materials (“Microstructure formation in molecular and polymer semiconductors assisted by nucleation agents”).

The June 7, 2013 Imperial College London news release by Joshua Howgego, which originated the news item, describes the researchers and the process in more detail,

Dr Natalie Stingelin, the leader of the study from the Department of Materials and Centre of Plastic Electronics at Imperial, says:

“Essentially, we have demonstrated a simple way to gain control over how crystals grow in electrically conducting ‘plastic’ semiconductors. Not only will this help industry fabricate plastic electronic devices like solar cells and sensors more efficiently. I believe it will also help scientists experimenting in other areas, such as protein crystallisation, an important part of the drug development process.”

Dr Stingelin and research associate Neil Treat looked at two additives, sold under the names IrgaclearÒ XT 386 and MilladÒ 3988, which are commonly used in industry. These chemicals are, for example, some of the ingredients used to improve the transparency of plastic drinking bottles. The researchers experimented with adding tiny amounts of these chemicals to the formulas of several different electrically conducting plastics, which are used in technologies such as security key cards, solar cells and displays.

The researchers found the additives gave them precise control over where crystals would form, meaning they could also control which parts of the printed material would conduct electricity. In addition, the crystallisations happened faster than normal. Usually plastic electronics are exposed to high temperatures to speed up the crystallisation process, but this can degrade the materials. This heat treatment treatment is no longer necessary if the additives are used.

Another industrially important advantage of using small amounts of the additives was that the crystallisation process happened more uniformly throughout the plastics, giving a consistent distribution of crystals.  The team say this could enable circuits in plastic electronics to be produced quickly and easily with roll-to-roll printing procedures similar to those used in the newspaper industry. This has been very challenging to achieve previously.

Dr Treat says: “Our work clearly shows that these additives are really good at controlling how materials crystallise. We have shown that printed electronics can be fabricated more reliably using this strategy. But what’s particularly exciting about all this is that the additives showed fantastic performance in many different types of conducting plastics. So I’m excited about the possibilities that this strategy could have in a wide range of materials.”

Dr Stingelin and Dr Treat collaborated with scientists from the University of California Santa Barbara (UCSB), and the National Renewable Energy Laboratory in Golden, US, and the Swiss Federal Institute of Technology on this study. The team are planning to continue working together to see if subtle chemical changes to the additives improve their effects – and design new additives.

There are some big plans for this discovery, from the news release,

They [the multinational team from ICL, UCSB, National Renewable Energy Laboratory, and Swiss Federal Institute of Technology]  will be working with the new Engineering and Physical Sciences Research Council (EPSRC)-funded Centre for Innovative Manufacturing in Large Area Electronics in order to drive the industrial exploitation of their process. The £5.6 million of funding for this centre, to be led by researchers from Cambridge University, was announced earlier this year [2013]. They are also exploring collaborations with printing companies with a view to further developing their circuit printing technique.

For the curious, here’s a link to and a citation for the published paper,

Microstructure formation in molecular and polymer semiconductors assisted by nucleation agents by Neil D. Treat, Jennifer A. Nekuda Malik, Obadiah Reid, Liyang Yu, Christopher G. Shuttle, Garry Rumbles, Craig J. Hawker, Michael L. Chabinyc, Paul Smith, & Natalie Stingelin. Nature Materials 12, 628–633 (2013) doi:10.1038/nmat3655 Published online 02 June 2013

This article is open access (at least for now).

e-Gnosis chip (nanopore sensor) competition on Marblar—winning money and developing a reputation for brilliance

It’s probably best to explain Marblar, a creative ‘playground’ or, as it could be called, a ‘wisdom of the crowd initiative’, before describing the e-Gnosis chip project.

Basically, Marblar is inviting people to participate in an online game/conversation where competitors make suggestions to ‘host’ inventors about how to best commercialize their inventions. Anyone can register to join in; there are two types of incentives for ‘game players’. First, they can accumulate marbles/points by voting and/or contributing ideas. Second, they can win cash prizes. Here’s how the Marblar community describes itself, from the About page,

Marblar is a creative playground that takes over-looked technology and unleashes a crowd of multi-disciplined, brilliant Marblars to discover new applications.

It is like a big game where many minds work together to realise the promise of science. Working with tech holders, we find the best technology deserving of a second look and transform these into challenges for the crowd of Marblars. The best ideas win points, kudos, and prizes. Best yet anyone can tackle any challenge. We don’t care what your background is…we care about your applied brilliance.

There’s a very interesting list of organizations backing this initiative, heavily weighted towards UK institutions but with a solid international presence, from the Partners page,

University of Oxford
Oxford, England

MRC Laboratory of Molecular Biology
Cambridge, England

Svaya Nanotechnologies
California, USA

Imperial Innovations
London, England

Edinburgh Research and Innovation
Edinburgh, Scotland

King’s College London
London, UK

Exploit Technologies
Singapore

Virginia Tech
Virginia, USA

Getting back to the game, for the hosted competitions, participants get to brainstorm ideas for a fixed period of time. These ideas are then refined over another fixed period of time with the inventor finally choosing a winner.

Now on to the specific game/project, the e-Gnosis chip (nanopore sensor). The inventor, Peter Kollensperger of the Imperial College London, has created a portable diagnostic device. There are many such diagnostic devices being developed all over the world, many of them designed for medical use. Kollensperger wants to find another market niche for his e-Gnosis chip device,

The vast majority of biosensors today are based on some form of optical readout to get the  results you want. You usually have a choice between inexpensive (but non-quantitative) methods such as lateral flow tests (e.g. pregnancy tests), which just show you a blue line if positive, or more sensitive tests that can tell you how much of the analyte is present using specialised optical equipment. These quantitative tests generally require several extra wash steps and additional reagents and are carried out by labs or on specialised microfluidic or robotic platforms. We wanted to develop a sensitive, quantitative technology that doesn’t require expensive platforms but instead:

  • Could be read using a low-cost smartphone or laptop accessory (<$20);
  • Works with a small amount of sample (~10 microlitre, such as a tiny drop of blood, urine or saliva)
  • Requires no (or just one) washing steps.
  • Runs several different tests on the same sample simultaneously.
  • Is as easy to use as a pregnancy test.

Here’s what the inventor is looking for (from the e-Gnosis chip page),

We’ve been looking at the field of medical diagnostics for a while, but the point-of-care market is highly competitive, fragmented into relatively small markets, with high entry barriers in the form of FDA [US Food and Drug Administration]/EMA [European Medicines Agency] approval. So for any medical diagnostic we’d need a large market, where our device’s unique features (multiplexing, rapid & simple point-of-care use without sample prep) offer a very significant competitive advantage, and can justify the high barrier costs for approval.

We’d be very interested to hear ideas about a consumer market to prove the device commercially, keeping in mind:

  • While the chip-manufacturing part of the process is cheap, the cost/test is unlikely to ever fall below $6-8 due to functionalization and assembly. We need an application where customers would pay enough to allow a reasonable profit margin.
  • Need a high-volume application to justify setup costs of chip-manufacture (>$300k). What’s your market size?
  • What would be the market entry route? Who’d be our commercial partners? What are the competing devices and their price? How would distinguish ourselves against these?

Here’s a little more about Kollensperger (from the e-Gnosis chip page),

I’m Peter Kollensperger and I’m working with Prof. Green in the Optical and Semiconductor Devices Group of the Electrical and Electronic Engineering Department at Imperial College London.

My research to date has focused on the use of nanotechnology for biosensing applications, but my overarching interest is in making diagnostic/sensing technologies more accessible both to doctors and the general public.

The combination of scalable nanotechnology and the hugely parallel processing of semiconductor foundries holds great promise for the area of biosensors and we are looking for applications where the end-user wants to get results on the go without spending a large upfront amount on a reader. This can be in medical diagnostics, but ideally would be in an underserved consumer market where the combination of properties of our chip can make a real difference.

The Marblar community offers video services for the inventors hosting competitions and this is Kollensperger’s

Diagnostics Array from Marblar on Vimeo.

There’s still time (20 days) to enter the competition. Good luck!

By the way, I owe a big thank you to Daniel Bayley for contacting me about the project and about Marblar.

Erasing time to create a temporal invisibility cloak

The idea of taking an eraser and just rubbing out embarrassing (or worse) incidents in one’s life is tempting but not yet possible despite efforts by researchers at Purdue University (Indiana, US). From a June 5, 2013 news item on ScienceDaily,

Researchers have demonstrated a method for “temporal cloaking” of optical communications, representing a potential tool to thwart would-be eavesdroppers and improve security for telecommunications.

“More work has to be done before this approach finds practical application, but it does use technology that could integrate smoothly into the existing telecommunications infrastructure,” said Purdue University graduate student Joseph Lukens, working with Andrew Weiner, the Scifres Family Distinguished Professor of Electrical and Computer Engineering.

Other researchers in 2012 invented temporal cloaking, but it cloaked only a tiny fraction — about a 10,000th of a percent — of the time available for sending data in optical communications. Now the Purdue researchers have increased that to about 46 percent, potentially making the concept practical for commercial applications.

The Purdue University June 5, 2013 news release, which originated the news item, describes the new technique,

The technique works by manipulating the phase, or timing, of light pulses. The propagation of light can be likened to waves in the ocean. If one wave is going up and interacts with another wave that’s going down, they cancel each other and the light has zero intensity. The phase determines the level of interference between these waves.

“By letting them interfere with each other you are able to make them add up to a one or a zero,” Lukens said. “The zero is a hole where there is nothing.”

Any data in regions where the signal is zero would be cloaked.

Controlling phase allows the transmission of signals in ones and zeros to send data over optical fibers. A critical piece of hardware is a component called a phase modulator, which is commonly found in optical communications to modify signals.

In temporal cloaking, two phase modulators are used to first create the holes and two more to  cover them up, making it look as though nothing was done to the signal.

“It’s a potentially higher level of security because it doesn’t even look like you are communicating,” Lukens said. “Eavesdroppers won’t realize the signal is cloaked because it looks like no signal is being sent.”

Such a technology also could find uses in the military, homeland security or law enforcement.

“It might be used to prevent communication between people, to corrupt their communication links without them knowing,” he said. “And you can turn it on and off, so if they suspected something strange was going on you could return it to normal communication.”

The technique could be improved to increase its operational bandwidth and the percentage of cloaking beyond 46 percent, he said.

In a July 14, 2011 posting I wrote about some of the research that laid the groundwork for this breakthrough at Purdue University,

Ian Sample in his July 13, 2011 posting on The Guardian Science blogs describes an entirely different approach, one that focusses on cloaking events rather than objects. From Samples’s posting,

The theoretical prospect of a “space-time” cloak – or “history editor” – was raised by Martin McCall and Paul Kinsler at Imperial College in a paper published earlier this year. The physicists explained that when light passes through a material, such as a lens, the light waves slow down. But it is possible to make a lens that splits the light in two, so that half – say the shorter wavelengths – speed up, while the other half, the longer wavelengths, slow down. This opens a gap in the light in which an event can be hidden, because half the light arrives before it has happened, and the other half arrives after the event.

In their paper, McCall and Kinsler outline a scenario whereby a video camera would be unable to record a crime being committed because there was a means of splitting the light such that 1/2 of it reached the camera before the crime occurred and the other 1/2  reached the camera afterwards. Fascinating, non?

It seems researchers at Cornell University have developed a device that can in a rudimentary fashion cloak events (from Samples’s posting),

The latest device, which has been shown to work for the first time by Moti Fridman and Alexander Gaeta at Cornell University, goes beyond the more familiar invisibility cloak, which aims to hide objects from view, by making entire events invisible.

Zeeya Merali in her extensive June 5, 2013 article (Temporal cloak erases data from history) for Nature provides an in depth explanation of the Purdue research,

To speed up the cloaking rate, Lukens and his colleagues exploited a wave phenomenon that was first discovered by British inventor Henry Fox Talbot in 1836. When a light wave passes through a series of parallel slits called a diffraction grating, it splits apart. The rays emanating from the slits combine on the other side to create an intricate interference pattern of peaks and troughs. Talbot discovered that this pattern repeats at regular intervals, creating what is now known as a Talbot carpet. There is also a temporal version of this effect in which you manipulate light over time to generate regular periods with zero light intensity, says Lukens. Data can be then be hidden in these holes in time.

Lukens’ team created its Talbot carpet in time by passing laser light through a ‘phase modulator’, a waveguide that also had an oscillating electrical voltage applied to it. As the voltage varied, the speed at which the light travelled through the waveguide was altered, splitting the light into its constituent frequencies and knocking these out of step. As predicted, at regular time intervals, the separate frequencies recombined destructively to generate time holes. Lukens’ team then used a second round of phase modulation to compress the energy further, expanding the duration of the time windows to 36 picoseconds (or 36 trillionths of a second).

The researchers tested the cloak to see if it was operating correctly by inserting a separate encoded data stream into the fibre during the time windows. They then applied two more rounds of phase modulation — to “undo the damage of the first two rounds”, says Lukens — decompressing the energy again and then combining the separated frequencies back into one. They confirmed that a user downstream would pick up the original laser signal alone, as though it had never been disturbed. The cloak successfully hid data added at a rate of 12.7 gigabits per second.

Unfortunately, the researchers were a little too successful and managed to erase the event entirely, which seems to answer a question I posed facetiously in my July 14, 2011 posting,

If you can’t see the object (light bending cloak), and you never saw the event (temporal cloak), did it exist and did it happen?

In addition to the military applications that Lukens imagines for temporal invisibility cloaks, Merali notes a another possibility in her Nature article,

Ironically, the first application of temporal cloaks may not be to hide data, but to help them to be read more accurately. The team has shown that splitting and recombining light waves in time creates increased periods in which the main data stream can be made immune to corruption by inserted data. “This could be useful to cut down crosstalk when multiple data streams share the same fibre,” says Lukens.

Gaeta agrees that the primary use for cloaking will probably be for innocent, mundane purposes. “People always imagine doing something illicit when they hear ‘cloaking’,” he says. “But these ways for manipulating light will probably be used to make current non-secret communication techniques more sophisticated.”

The research paper can be found here,

A temporal cloak at telecommunication data rate by Joseph M. Lukens, Daniel E. Leaird & Andrew M. Weiner. Nature (2013) doi:10.1038/nature12224 Published online 05 June 2013

This paper is behind a paywall. Fortunately, anyone can access my June 5, 2013 posting (Memories, science, archiving, and authenticity) which seems relevant here for two reasons. First, there’s a mention of a new open access initiative in the US which would make this research more freely available in the future with a proposal (there may be others as this initiative develops) called the Clearinghouse for the Open Research of the United States (CHORUS).  I imagine there would be some caveats and I notice that Nature magazine has signed up for this proposal. I think the second reason for mentioning yesterday’s post is pretty obvious, memory/erasing, etc.

COllaborative Network for Training in Electronic Skin Technology (CONTEST) looking for twelve researchers

The CONTEST (COllaborative Network for Training in Electronic Skin TechnologyCOllaborative Network for Training in Electronic Skin Technology) project was launched today in Italy. According to the Aug. 21, 2012 news item on Nanowerk,

“Flexible electronics” is one of the most significant challenges in the field of future electronics. The possibility of realizing flexible and bendable electronic circuits, that can be rolled up, twisted or inserted in films around objects, would introduce a range of infinite applications in multiple fields, including healthcare, robotics and energy.

In this area, the Fondazione Bruno Kessler of Trento will coordinate the CONTEST project (COllaborative Network for Training in Electronic Skin Technology), an Initial Training Network (ITN) Marie Curie project funded by the European Commission involving European research, academic and business players. These include seven full partners (Fondazione Bruno Kessler, Italy; ST Microelectronics, Italy; Technical University Munich, Germany; Fraunhofer EMFT, Germany; University College London, UK; Imperial College London, UK; and Shadow Robotics Company, UK) and two associate partners (University of Cambridge, UK, and University of Tokyo, Japan).

The CONTEST project page at the Fondazione Bruno Kessler website offers more details,

At the heart of the CONTEST programme lies the multidisciplinary research training of young researchers. The CONTEST network will recruit twelve excellent Early-Stage Researchers (e.g. PhD students) and two Experienced Researchers (e.g. Post-Doc fellows). Information for submitting applications is available at the project’s website: http://www.contest-itn.eu/.
CONTEST activities will be coordinated by Ravinder S. Dahiya, researcher at the Bio-MEMS Unit (BIO-Micro-Electro-Mechanical-Systems) of  the Center for Materials and Microsystems (Fondazione Bruno Kessler) and by Leandro Lorenzelli, head of the Bio-MEMS Unit.
“The disruptive flexible electronics technology – says Ravinder S. Dahiya – will create change and improve the electronic market landscape and usher in a new revolution in multifunctional electronics. It will transform to an unprecedented degree our view of electronics and how we, as a society, interact with intelligent and responsive systems.”
“The investigation, in a very multidisciplinary framework, of technological approaches for thin flexible components – explains Leandro Lorenzelli – will generate new paradigms and concepts for microelectronic devices and systems with new functionalities tailored to the needs of a wide range of applications including robotics, biomedical instrumentations and smart cities.”

Here’s more about the 12 researchers they’re recruiting, excerpted from the Job Openings page on the CONTEST project website (Note: I have removed some links),

We have been awarded a large interdisciplinary project on electronic skin and applications, called CONTEST (COllaborative Network for Training in Electronic Skin Technology). We are therefore looking for 12 excellent Early-Stage Researchers (e.g. PhD students) and 2 Experienced Researchers (e.g. Post-Doc), associated to:

  • Fondazione Bruno Kessler, Trento, Italy (2 Early-Stage Researcher positions on silicon based flexible sensors (e.g. touch sensors), electronic circuits and 1 Experienced Researcher position on system integration)  …,
  • ST Microelectronics, Catania, Italy (2 Early-Stage Researcher positions on chemical/physical sensors on flexible substrates, and metal patterned substrates for integrating flexible sensing elements)…,
  • Technical University Munich, Germany (3 Early-Stage Researcher positions on organic semiconductor based electronics devices and circuits, modeling of flexible devices and sensors … , and artificial skin in humanoids…,
  • Fraunhofer EMFT, Munich, Germany (1 Early-Stage Researcher position on assembly on film substrates and foil integration as well as 1 Experienced Researcher position on reliability and ESD issues of components during flex integration) … ,
  • University College London, UK (2 Early-Stage Researcher positions on organic semiconductor based interconnects, solutions processed sensors, alternative on-skin energy schemes, patterning of e-skin and stretchable interconnects using blends of graphene in polymeric materials …
  • Imperial College London, UK (1 Early-Stage Researcher position on human sensori-motor control and robotics) …, and
  • Shadow Robotics Company, UK (1 Early-Stage Researcher position on biorobotics and mechatronics) ….

Mobility rules apply to all these positions. Researchers can be of any nationality. They are required to undertake trans-national mobility (i.e. move from one country to another) when taking up their appointment. One general rule applies to the appointment of researchers: At the time of recruitment by the host organization, researchers must not have resided or carried out their main activity (work, studies, etc.) in the country of their host organization (i.e. recruiting institute) for more than 12 months in the 3 years immediately prior to the reference date. Short stays such as holidays and/or compulsory national service are not taken into account.

Good luck to all who apply! Priority will be given to applications received by Sept. 30, 2012.