Tag Archives: UK

Biosensing devices from Scotland

The timing for Deborah Rowe’s article in the Guardian newspaper is fascinating. Rowe is writing about nanoscale biosensors developed at the University of Edinburgh, research published in Dec. 2013, while her piece, published Sept. 9, 2014, appears less than 10 days before Scotland’s vote (Sept. 18, 2014) on the question of whether or not it should be independent. Also interesting, the published paper is available as open access until the end of Sept. 2014, which seems like a strategic time period to give open access to your paper.

That said, this is an exciting piece of research if you’re particularly interested in biosensors and ways to produce them more cheaply and at a higher volume (from Rowe’s Sept. 9, 2014 article),

An interdisciplinary research team from the Schools of Engineering and Chemistry at the University of Edinburgh (in association with Nanoflex Ltd), has overcome some of the constraints associated with conventional nano-scale electrode arrays, to develop the first precision-engineered nanoelectrode array system with the promise of high-volume and low-cost.*

Such miniaturised electrode arrays have the potential to provide a faster and more sensitive response to, for example, biomolecules than current biosensors. This would make them invaluable components in the increasingly sensitive devices being developed for biomedical sensing and electrochemical applications.

Rowe goes on to describe the researchers’ Microsquare Nanoband Edge Electrode (MNEE) array technology in lucid and brief detail. For those who want more, here’s a link to and a citation for the paper,

Nanoscale electrode arrays produced with microscale lithographic techniques for use in biomedical sensing applications by Jonathan G. Terry, Ilka Schmüser, Ian Underwood, Damion K. Corrigan, Neville J. Freeman, Andrew S. Bunting, Andrew R. Mount, Anthony J. Walton. IET Nanobiotechnology, Volume 7, Issue 4, December 2013, p. 125 – 134
DOI:  10.1049/iet-nbt.2013.0049 , Print ISSN 1751-8741, Online ISSN 1751-875X Published Oct. 29, 2013

Given the timing of the Guardian article and the availability of the paper for free access, I was moved to find information about the funding agencies, from the researchers’ IET paper,

Support from the Scottish Funding Council (SFC) is acknowledged through the Edinburgh Research Partnership in engineering and mathematics (ERPem) and the Edinburgh and St Andrews Chemistry (EaStCHEM) initiatives, along with knowledge transfer funding. Support from the Engineering and Physical Sciences Research Council (EPSRC) of the UK through the IeMRC (Smart Microsystems – FS/01/02/10) Grant is acknowledged. Ilka Schmüser thanks the EPSRC and the University of Edinburgh for financial support.

And, there was this from Rowe’s article,

The work is part of a larger R&D programme on the development of smart sensors at the University of Edinburgh. It involves staff and students from the Schools of Engineering and Chemistry thus providing the required broad set of skills and experience. The resulting MNEE technology is currently being commercialised by Nanoflex Ltd.

So, the funding comes from Scottish and UK sources and the company which is commercializing the MNEE is located in the North West of England in the  Sci-Tech Daresbury Campus (from the company’s LinkedIn page). This certainly illustrates how entwined the Scottish and UK science scenes are entwined as is the commercialization process.

I last mentioned Scotland, science, and the independence vote in a July 8, 2014 posting which covers some of the ‘pro’ and ‘con’ thinking at the time.

Tibetan Buddhist singing bowls inspire more efficient solar cells

There’s no mention as to whether or not Dr Niraj Lal practices any form of meditation or how he came across Tibetan Buddhist singing bowls but somehow he was inspired by them when studying for his PhD at Cambridge University (UK). From a Sept. 8, 2014 news item by Niall Byrne for physorg.com,

The shape of a centuries-old Buddhist singing bowl has inspired a Canberra scientist to re-think the way that solar cells are designed to maximize their efficiency.

Dr Niraj Lal, of the Australian National University,  found during his PhD at the University of Cambridge, that small nano-sized versions of Buddhist singing bowls resonate with light in the same way as they do with sound, and he’s applied this shape to solar cells to increase their ability to capture more light and convert it into electricity.

A Sept. ?, 2014 news release from Australian science communication company, Science in Public, fills in a few more details without any mention of Lal’s meditation practices, should he have any,

“Current standard solar panels lose a large amount of light-energy as it hits the surface, making the panels’ generation of electricity inefficient,” says Niraj. “But if the cells are singing bowl-shaped, then the light bounces around inside the cell for longer”.

Normally used in meditation, music, and relaxation, Buddhist singing bowls make a continuous harmonic ringing sound when the rim of the metal bowl is vibrated with a wooden or other utensil.

During his PhD, Niraj discovered that his ‘nanobowls’ manipulated light by creating a ‘plasmonic’ resonance, which quadrupled the laboratory solar cell’s efficiency compared to a similarly made flat solar cell.

Now, Niraj and his team aim to change all that by applying his singing-bowl discovery to tandem solar cells: a technology that has previously been limited to aerospace applications.

In research which will be published in the November issue of IEEE Journal of Photonics, Niraj and his colleagues have shown that by layering two different types of solar panels on top of each other in tandem, the efficiency of flat rooftop solar panels can achieve 30 per cent—currently, laboratory silicon solar panels convert only 25 per cent of light into electricity, while commercial varieties convert closer to 20 per cent.

The tandem cell design works by absorbing a sunlight more effectively —each cell is made from a different material so that it can ‘see’ a different light wavelength.

“To a silicon solar cell, a rainbow just looks like a big bit of red in the sky—they don’t ‘see’ the blue, green or UV light—they convert all light to electricity as if it was red ,” says Niraj. “But when we put a second cell on top, which ‘sees’ the blue part of light, but allows the red to pass through to the ‘red-seeing’ cell below, we can reach a combined efficiency of more than 30 percent.”

Niraj and a team at ANU are now looking at ways to super-charge the tandem cell design by applying the Buddhist singing bowl shape to further increase efficiency.

“If we can make a solar cell that ‘sees’ more colours and  keeps the right light in the right layers, then we could increase efficiency even further,” says Niraj.

“Every extra percent in efficiency saves you thousands of dollars over the lifetime of the panel,” says Niraj. “Current roof-top solar panels have been steadily increasing in efficiency, which has been a big driver of the fourfold drop in the price for these panels over the last five years.”

More importantly, says Niraj, greater efficiency will allow solar technology to compete with fossil fuels and meet the challenges of climate change and access.

“Electricity is also one of the most enabling technologies we have ever seen, and linking people in rural areas around the world to electricity is one of the most powerful things we can do.”

At the end of the Science in Public news release there’s mention of a science communication competition,

Niraj was a 2014 national finalist of FameLab Australia. FameLab is a global science communication competition for early-career scientists. His work is supported by the Australian Research Council and ARENA – the Australian Renewable Energy Agency.

About FameLab

In 2014, the British Council and Fresh Science have joined forces to bring FameLab to Australia.

FameLab Australia will offer specialist science media training and, ultimately, the chance for early-career researchers to pitch their research at the FameLab International Grand Final in the UK at The Times Cheltenham Science Festival from 3 to 5 June 2014.

FameLab is an international communication competition for scientists, including engineers and mathematicians. Designed to inspire and motivate young researchers to actively engage with the public and with potential stakeholders, FameLab is all about finding the best new voices of science and engineering across the world.

Founded in 2005 by The Times Cheltenham Science Festival, FameLab, working in partnership with the British Council, has already seen more than 5,000 young scientists and engineers participate in over 23 different countries — from Hong Kong to South Africa, USA to Egypt.

Now, FameLab comes to Australia in a landmark collaboration with the British Council and Fresh Science — Australia’s very own science communication competition.

For more information about FameLab Australia, head to www.famelab.org.au

You can find out more about Australia’s Fresh Science here.

Getting back to Dr. Lal, here’s a video he made about his work and where he demonstrates a Tibetan Buddhist singing bowl (this is a very low tech video and the sound quality isn’t great),

Here’s a link to and a citation for Lal’s most recent paper,

Optics and Light Trapping for Tandem Solar Cells on Silicon by Lal, N.N.; White, T.P. ; and Catchpole, K.R. Photovoltaics, IEEE Journal of  (Volume:PP ,  Issue: 99) Page(s): 1 – 7 ISSN : 2156-3381 DOI: 10.1109/JPHOTOV.2014.2342491 Published online 19 August 2014

The paper is behind a paywall but there is open access to Lal’s 2012 University of Cambridge PhD thesis on his approach,

Enhancing solar cells with plasmonic nanovoids by Lal, Niraj Narsey
URI: http://www.dspace.cam.ac.uk/handle/1810/243864 Date:2012-07-03

Hap;y reading!

Monitoring health with graphene rubber bands

An Aug. 20, 2014 news item on Azonano highlights graphene research from the University of Surrey (UK) and Trinity College Dublin (Ireland),

Although body motion sensors already exist in different forms, they have not been widely used due to their complexity and cost of production.

Now researchers from the University of Surrey and Trinity College Dublin have for the first time treated common elastic bands with graphene, to create a flexible sensor that is sensitive enough for medical use and can be made cheaply.

An Aug. 15, 2014 University of Surrey press release (also on EurekAlert), which originated the news item, describes the innovation (Note: A link has been removed),

Once treated, the rubber bands remain highly pliable. By fusing this material with graphene – which imparts an electromechanical response on movement – the material can be used as a sensor to measure a patient’s breathing, heart rate or movement, alerting doctors to any irregularities.

“Until now, no such sensor has been produced that meets these needs,” said Surrey’s Dr Alan Dalton. “It sounds like a simple concept, but our graphene-infused rubber bands could really help to revolutionise remote healthcare – and they’re very cheap to manufacture.”

“These sensors are extraordinarily cheap compared to existing technologies. Each device would probably cost pennies instead of pounds, making it ideal technology for use in developing countries where there are not enough medically trained staff to effectively monitor and treat patients quickly.” [commented corresponding author, Professor Jonathan Coleman from Trinity College, Dublin]

Trinity College Dublin issued an Aug. 20, 2014 press release, which provides a little more technical detail and clarifies who led the team for anyone who may been curious about the matter,

The team – led by Professor of Chemical Physics at Trinity, Jonathan Coleman, one of the world’s leading nanoscientists – infused rubber bands with graphene, a nano-material derived from pencil lead which is 10,000 times smaller than the width of a human hair. This process is simple and compatible with normal manufacturing techniques. While rubber does not normally conduct electricity, the addition of graphene made the rubber bands electrically conductive without degrading the mechanical properties of the rubber. Tests showed that any electrical current flowing through the graphene-infused rubber bands was very strongly affected if the band was stretched. As a result, if the band is attached to clothing, the tiniest movements such as breath and pulse can be sensed.

The discovery opens up a host of possibilities for the development of wearable sensors from rubber, which could be used to monitor blood pressure, joint movement and respiration. Other applications of rubber-graphene sensors could be in the automotive industry (to develop sensitive airbags); in robotics, in medical device development (to monitor bodily motion), as early warning systems for cot death in babies or sleep apnoea in adults. They could also be woven into clothing to monitor athletes’ movement or for patients undergoing physical rehabilitation.

Professor Coleman said: “Sensors are becoming extremely important in medicine, wellness and exercise, medical device manufacturing, car manufacturing and robotics, among other areas. Biosensors, which are worn on or implanted into the skin, must be made of durable, flexible and stretchable materials that respond to the motion of the wearer. By implanting graphene into rubber, a flexible natural material, we are able to completely change its properties to make it electrically conductive, to develop a completely new type of sensor. Because rubber is available widely and cheaply, this unique discovery will open up major possibilities in sensor manufacturing worldwide.”

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

Sensitive, High-Strain, High-Rate Bodily Motion Sensors Based on Graphene–Rubber Composites by Conor S. Boland, Umar Khan, Claudia Backes, Arlene O’Neill, Joe McCauley, Shane Duane, Ravi Shanker, Yang Liu, Izabela Jurewicz, Alan B. Dalton, and Jonathan N. Coleman. ACS Nano, Article ASAP DOI: 10.1021/nn503454h Publication Date (Web): August 6, 2014

Copyright © 2014 American Chemical Society

This paper is open access (I was able to open the HTML version this morning, Aug. 20, 2014). As well the researchers have made this image illustrating their work available,

[downloaded from http://pubs.acs.org/doi/full/10.1021/nn503454h]

[downloaded from http://pubs.acs.org/doi/full/10.1021/nn503454h]

White beetles and complex photonic nanostructures

At least one species of white beetles which have excited scientists with their complex nanostructures are native to Southeast Asia according to an Aug. 15, 2014 news item on Nanowerk,

The physical properties of the ultra-white scales on certain species of beetle could be used to make whiter paper, plastics and paints, while using far less material than is used in current manufacturing methods.

The Cyphochilus beetle, which is native to South-East Asia, is whiter than paper, thanks to ultra-thin scales which cover its body. A new investigation of the optical properties of these scales has shown that they are able to scatter light more efficiently than any other biological tissue known, which is how they are able to achieve such a bright whiteness.

An Aug. 15, 2014 University of Cambridge press release (also on EurekAlert), which originated the news item, describes the properties needed to create the optical conditions necessary for the colour white to be seen,

Animals produce colours for several purposes, from camouflage to communication, to mating and thermoregulation. Bright colours are usually produced using pigments, which absorb certain wavelengths of light and reflect others, which our eyes then perceive as colour.

To appear as white, however, a tissue needs to reflect all wavelengths of light with the same efficiency. The ultra-white Cyphochilus and L. Stigma beetles produce this colouration by exploiting the geometry of a dense complex network of chitin – a molecule similar in structure to cellulose, which is found throughout nature, including in the shells of molluscs, the exoskeletons of insects and the cell walls of fungi. The chitin filaments are just a few billionths of a metre thick, and on their own are not particularly good at reflecting light.

The research, a collaboration between the University of Cambridge and the European Laboratory for non-Linear Spectroscopy in Italy has shown that the beetles have optimised their internal structure in order to produce maximum white with minimum material, like a painter who needs to whiten a wall with a very small quantity of paint. This efficiency is particularly important for insects that fly, as it makes them lighter.

Here’s what the Cyphochilus beetle looks like,

Cyphochilus beetle Credit: Lorenzo Cortese and Silvia Vignolini

Cyphochilus beetle Credit: Lorenzo Cortese and Silvia Vignolini Courtesy University of Cambridge

The press release goes on to describe the beetle’s optical properties in greater detail,

Over millions of years of evolution the beetles have developed a compressed network of chitin filaments. This network is directionally-dependent, or anisotropic, which allows high intensities of reflected light for all colours at the same time, resulting in a very intense white with very little material.

“Current technology is not able to produce a coating as white as these beetles can in such a thin layer,” said Dr Silvia Vignolini of the University’s Cavendish Laboratory, who led the research. “In order to survive, these beetles need to optimise their optical response but this comes with the strong constraint of using as little material as possible in order to save energy and to keep the scales light enough in order to fly. Curiously, these beetles succeed in this task using chitin, which has a relatively low refractive index.”

The secret lies in the beetles’ nanostructures,

Exactly how this could be possible remained unclear up to now. The researchers studied how light propagates in the white scales, quantitatively measuring their scattering strength for the first time and demonstrating that they scatter light more efficiently than any other low-refractive-index material yet known.

“These scales have a structure that is truly complex since it gives rise to something that is more than the sum of its parts,” said co-author Dr Matteo Burresi of the Italian National Institute of Optics in Florence. “Our simulations show that a randomly packed collection of its constituent elements by itself is not sufficient to achieve the degree of brightness that we observe.”

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

Bright-White Beetle Scales Optimise Multiple Scattering of Light by Matteo Burresi, Lorenzo Cortese, Lorenzo Pattelli, Mathias Kolle, Peter Vukusic, Diederik S. Wiersma, Ullrich Steiner, & Silvia Vignolini.  Scientific Reports 4, Article number: 6075 doi:10.1038/srep06075 Published 15 August 2014

This paper is open access.

Science and the arts: a science rap promotes civil discussion about science and religion; a science movie and a play; and a chemistry article about authenticating a Lawren Harris painting

Canadian-born rapper of science and many other topics, Baba Brinkman sent me an update about his current doings (first mentioned in an Aug. 1, 2014 posting featuring his appearances at the 2014 Edinburgh Fringe Festival, his Rap Guide to Religion being debuted at the Fringe, and his Kickstarter campaign to raise money for the creation of an animated rap album of his news Rap Guide to Religion), Note: Links have been removed,

Greetings from Edinburgh! In the past two and half weeks I’ve done fifteen performances of The Rap Guide to Religion for a steadily building audience here at the Fringe, and we recently had a whole pile of awesome reviews published, which I will excerpt below, but first a funny story.

Yesterday [August 14, 2014] BBC [British Broadcasting Corporation] Sunday Morning TV was in to film my performance. They had a scheme to send a right wing conservative Christian to the show and then film us having an argument afterwards. The man they sent certainly has the credentials. Reverend George Hargreaves is a Pentecostal Minister and former leader of the UK Christian Party, as well as a young earth creationist and strong opponent of abortion and homosexuality. He led the protests that got “Jerry Springer the Opera” shut down in London a few years back, and is on record as saying that religion is not an appropriate subject for comedy. Before he converted to Christianity, the man was also a DJ and producer of pop music for the London gay scene, interesting background.

So after an hour of cracking jokes at religion’s expense, declaring myself an unapologetic atheist, and explaining why evolutionary science gives a perfectly satisfying naturalistic account of where religion comes from, I sat down with Reverend George and was gobsmacked when he started the interview with: “I don’t know if we’re going to have anything to debate about… I LOVED your show!” We talked for half an hour with the cameras rolling and at one point George said “I don’t know what we disagree about,” so I asked him: “Do you think one of your ancestors was a fish?” He declared that statement a fishy story and denied it, and then we found much to disagree about.

I honestly thought I had written a hard-hitting, provocative and controversial show, but it turns out the religious are loving it as much as the nonbelievers – and I’m not sure how I feel about that. I asked Reverend George why he wasn’t offended, even though he’s officially against comedy that targets religion, and he told me it’s because I take the religious worldview seriously, instead of lazily dismissing it as delusional. The key word here is “lazily” rather than “delusional” because I don’t pull punches about religion being a series of delusions, but I don’t think those delusions are pointless. I think they have evolved (culturally and genetically) to solve adaptive problems in the past, and for religious people accustomed to atheists being derisive and dismissive that’s a (semi) validating perspective.

To listen to songs from The Rap Guide to Religion, you need to back my Kickstarter campaign so I can raise the money to produce a proper record. To check out what the critics here in Edinburgh have to say about my take on religion, read on. And if you want to help organize a gig somewhere, just let me know. The show is open for bookings.

On Sunday Morning [August 17, 2014 GMT] my segment with Reverend George will air on BBC One, so we’ll see what a million British people think of the debate.

All the best from the religious fringe,

Baba

Here’s a link to the BBC One Sunday Morning Live show, where hopefully you’ll be able to catch the segment featuring Baba and Reverend George Hargreaves either livestreamed or shortly thereafter.

A science movie and a science play

Onto the science movie and the play: David Bruggeman on his Pasco Phronesis blog writes about two upcoming movie biopics featuring Alan Turing and Stephen Hawking respectively, in an Aug. 8, 2014 posting. Having covered the Turing movie here (at length) in a July 22, 2014 posting here’s the new information about the Hawking movie from David’s Aug, 8, 2014 posting,

Alan Turing and Stephen Hawking are noted British scientists, well recognized for their work and for having faced significant challenges in their lives.  While they were in different fields and productive in different parts of the 20th century (Hawking is still with us), their stories will compete in movieplexes (at least in the U.S.) this November.

The Theory of Everything is scheduled for release on November 7 and focuses on the early career and life of Hawking.  He’s portrayed by Eddie Redmayne, and the film is directed by James Marsh.  Marsh has several documentaries to his credit, including the Oscar-winning Man on Wire.  Theory is the third film project on Hawking since 2004, but the first to get much attention outside of the United Kingdom (this might explain why it won’t debut in the U.K. until New Year’s Day).  It premieres at the Toronto International Film Festival next month [Sept. 2014].

David features some trailers for both movies and additional information.

Interestingly the science play focuses on the friendship between a female UK scientist and her former student, Margaret Thatcher (a UK Prime Minister). From an Aug. 13, 2014 Alice Bell posting on the Guardian science blog network (Note: Links have been removed),

Adam Ganz’s new play – The Chemistry Between Them, to be broadcast on Radio 4 this month – explores one of the most intriguing friendships in the history of science and politics: Margaret Thatcher and Dorothy Hodgkin.

As well as winning the Nobel Prize in Chemistry for her pioneering scientific work on the structures of proteins, Hodgkin was a left-wing peace campaigner who was awarded the Soviet equivalent of the Nobel Peace Prize, the Order of Lenin. Hardly Thatcher’s type, you might think. But Hodgkin was Thatcher’s tutor at university, and the relationships between science, politics and women in high office are anything but straightforward.

I spoke to Ganz about his interest in the subject, and started by asking him to tell us more about the play.

… they stayed friends throughout Dorothy’s life. Margaret Thatcher apparently had a photo of Dorothy Hodgkin in Downing Street, and they maintained a kind of warm relationship. The play happens in two timescales – one is a meeting in 1983 in Chequers where Dorothy came to plead with Margaret to take nuclear disarmament more seriously at a time when Cruise missiles and SS20s were being stationed in Europe. In fact I’ve set it – I’m not sure of the exact date – shortly after the Korean airliner was shot down, when the Russians feared Nato were possibly planning a first strike. And that is intercut with the time when Margaret is studying chemistry and looking at her journey; what she learned at Somerville, but especially what she learned from Dorothy.

Here’s a link to the BBC 4 webpage for The Chemistry Between Them. I gather the broadcast will be Weds., Aug. 20, 2014 at 1415 hours GMT.

Chemistry and authentication of a Lawren Harris painting

The final item for this posting concerns Canadian art, chemistry, and the quest to prove the authenticity of a painting. Roberta Staley, editor of Canadian Chemical News (ACCN), has written a concise technical story about David Robertson’s quest to authenticate a painting he purchased some years ago,

Fourteen years ago, David Robertson of Delta, British Columbia was holidaying in Ontario when he stopped at a small antique shop in the community of Bala, two hours north of Toronto in cottage country. An unsigned 1912 oil painting caught his attention. Thinking it evocative of a Group of Seven painting, Robertson paid the asking price of $280 and took it home to hang above his fireplace.

Roberta has very kindly made it available as a PDF: ChemistryNews_Art.Mystery.Group.7. It will also be available online at the Canadian Chemical News website soon. (It’s not in the July/August 2014 issue.)

For anyone who might recognize the topic, I wrote a sprawling five-part series (over 5000 words) on the story starting with part one. Roberta’s piece is 800 words and offers her  account of the tests for both Autumn Harbour and the authentic Harris painting, Hurdy Gurdy. I was able to attend only one of them (Autumn Harbour).

David William Robertson, Autumn Harbour’s owner has recently (I received a notice on Aug. 13, 2014) updated his website with all of the scientific material and points of authentication that he feels prove his case.

Have a very nice weekend!

Wearable solar panels with perovskite

There was a bit of a flutter online in late July 2014 about solar cell research and perovskite, a material that could replace silicon therefore making solar cells more affordable, which hopefully would lead to greater adoption of the technology. Happily, the publishers of the study seem to have reissued their news release (h/t Aug. 11, 2014 news item on Nanwerk).

From the Wiley online press release Nr. 29/2014,

Textile solar cells are an ideal power source for small electronic devices incorporated into clothing. In the journal Angewandte Chemie, Chinese scientists have now introduced novel solar cells in the form of fibers that can be woven into a textile. The flexible, coaxial cells are based on a perovskite material and carbon nanotubes; they stand out due to their excellent energy conversion efficiency of 3.3 % and their low production cost.

The dilemma for solar cells: they are either inexpensive and inefficient, or they have a reasonable efficiency and are very expensive. One solution may come from solar cells made of perovskite materials, which are less expensive than silicon and do not require any expensive additives. Perovskites are materials with a special crystal structure that is like that of perovskite, a calcium titanate. These structures are often semiconductors and absorb light relatively efficiently. Most importantly, they can move electrons excited by light for long distances within the crystal lattice before they return to their energetic ground state and take up a solid position – a property that is very important in solar cells.

A team led by Hisheng Peng at Fudan University in Shanghai has now developed perovskite solar cells in the form of flexible fibers that can be woven into electronic textiles. Their production process is relatively simple and inexpensive because it uses a solution-based process to build up the layers.

The anode is a fine stainless steel wire coated with a compact n-semiconducting titanium dioxide layer. A layer of porous nanocrystalline titanium dioxide is deposited on top of this. This provides a large surface area for the subsequent deposition of the perovskite material CH3NH3PbI3. This is followed by a layer made of a special organic material. Finally a transparent layer of aligned carbon nanotubes is continuously wound over the whole thing to act as the cathode. The resulting fiber is so fine and flexible that it can be woven into textiles.

The perovskite layer absorbs light, that excites electrons and sets them free, causing a charge separation between the electrons and the formally positively charged “holes” The electrons enter the conducting band of the compact titanium dioxide layer and move to the anode. The “holes” are captured by the organic layer. The large surface area and the high electrical conductivity of the carbon nanotube cathode aid in the rapid conduction of the charges with high photoelectric currents. The fiber solar cell can attain an energy conversion efficiency of 3.3 %, exceeding that of all previous coaxial fiber solar cells made with either dyes or polymers.

Here’s an image used in the press release illustrating the new fiber,

[downloaded from http://www.wiley-vch.de/vch/journals/2002/press/201429press.pdf]

[downloaded from http://www.wiley-vch.de/vch/journals/2002/press/201429press.pdf]

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

Integrating Perovskite Solar Cells into a Flexible Fiber by Longbin Qiu, Jue Deng, Xin Lu, Zhibin Yang, and Prof. Huisheng Peng. Angewandte Chemie International Edition DOI: 10.1002/anie.201404973 Article first published online: 22 JUL 2014

© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

I found a second item about perovskite and solar cells in a May 16, 2014 article by Vicki Marshall for Chemistry World which discussed some research in the UK (Note: Links have been removed),

A lead-free and non-toxic alternative to current perovskite solar-cell technology has been reported by researchers in the UK: tin halide perovskite solar cells. They are also cheaper to manufacture than the silicon solar cells currently dominating the market.

Nakita Noel, part of Henry Snaith’s research team at the University of Oxford, describes how perovskite materials have caused a bit of a whirlwind since they came out in 2009: ‘Everybody that’s working in the solar community is looking to beat silicon.’ Despite the high efficiency of conventional crystalline silicon solar cells (around 20%), high production and installation costs decrease their economic feasibility and widespread use.

The challenge to find a cheaper alternative led to the development of perovskite-based solar cells, as organic–inorganic metal trihalide perovskites have both abundant and cheap starting materials. However, the presence of lead in some semiconductors could create toxicology issues in the future. As Noel puts it ‘every conference you present at somebody is bound to put up their hand and ask “What about the lead – isn’t this toxic?”’

Brian Hardin, co-founder of PLANT PV, US, and an expert in new materials for photovoltaic cells, says the study ‘should be considered a seminal work on alternative perovskites and is extremely valuable to the field as they look to better understand how changes in chemistry affect solar cell performance and stability.’

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

Lead-free organic–inorganic tin halide perovskites for photovoltaic applications by Nakita K. Noel, Samuel D. Stranks, Antonio Abate, Christian Wehrenfennig, Simone Guarnera, Amir-Abbas Haghighirad, Aditya Sadhana, Giles E. Eperon, Sandeep K. Pathak, Michael B. Johnston, Annamaria Petrozza, Laura M. Herza, and Henry J. Snaith. Energy Environ. Sci., 2014, Advance Article DOI: 10.1039/C4EE01076K First published online 01 May 2014

This article was open access until June 27, 2014 but now it is behind a paywall.

I notice there’s no mention of lead in the materials describing the research paper from the Chinese scientists. Perhaps they were working with lead-free materials.

Metaphors in a brief overview of the nanomedicine scene circa August 2014

An Aug. 1, 2014 article by Guizhi Zhu (University of Florida), Lei Mei ((Hunan University; China), and Weihong Tan (University of Florida) for The Scientist provides an overview of the latest and greatest regarding nanomedicine while underscoring the persistence of certain medical metaphors. This overview features a prediction and a relatively benign (pun intended) metaphor,

Both the academic community and the pharmaceutical industry are making increasing investments of time and money in nanotherapeutics. Nearly 50 biomedical products incorporating nanoparticles are already on the market, and many more are moving through the pipeline, with dozens in Phase 2 or Phase 3 clinical trials. Drugmakers are well on their way to realizing the prediction of Christopher Guiffre, chief business officer at the Cambridge, Massachusetts–based nanotherapeutics company Cerulean Pharma, who last November forecast, “Five years from now every pharma will have a nano program.”

Technologies that enable improved cancer detection are constantly racing against the diseases they aim to diagnose, and when survival depends on early intervention, losing this race can be fatal. [emphasis mine] While detecting cancer biomarkers is the key to early diagnosis, the number of bona fide biomarkers that reliably reveal the presence of cancerous cells is low. To overcome this challenge, researchers are developing functional nanomaterials for more sensitive detection of intracellular metabolites, tumor cell–membrane proteins, and even cancer cells that are circulating in the bloodstream. (See “Fighting Cancer with Nanomedicine,” The Scientist, April 2014.)

So, the first metaphor ‘racing’ gives the reader a sense of urgency, the next ones, including “fighting cancer’, provoke a somewhat different state of mind,

Eye on the target

The prototype of targeted drug delivery can be traced back to the concept of a “magic bullet,” proposed by chemotherapy pioneer and 1908 Nobel laureate Paul Ehrlich. [emphasis mine] E[hrlich envisioned a drug that could selectively target a disease-causing organism or diseased cells, leaving healthy tissue unharmed. A century later, researchers are developing many types of nanoscale “magic bullets” that can specifically deliver drugs into target cells or tissues.

It would seem we might be in a state of war as you 'fight cancer' with your 'eyes on the target' as you 'shoot magic bullets' in time to celebrate the 100th anniversary of the start to World War I.

Kostas Kostarelos wrote a Nov. 29, 2013 posting for the Guardian Science Blogs where he (professor of nanomedicine at the University of Manchester and director of the university's Nanomedicine Lab) discussed war metaphors in medicine and possible unintended consequences (Note: A link has been removed). Here's his discussion about the metaphors,

Almost every night I have watched the news these past few months my senses have been assaulted by unpleasant, at times distressing, images of war: missiles, killings and chemical bombs in Syria, Kenya, the USA. I wake up the next morning, trying to forget what I watched the night before, and going to work with our researchers to develop the next potential high-tech cure for cancer, thinking: "does what we do matter at all … ?"

So I was intrigued by an article that will be published in one of the scientific journals in our field entitled: "Nanomedicine metaphors: from war to care". The next lab meeting we had was very awkward, because I was constantly thinking that indeed a lot of the words we were using to communicate our science were directly imported from the language of war. Targeting, stealth nanoparticle, smart bomb, elimination, triggered release, cell death. I struggled to find alternative language.

...

... Hollywood analogies and simplistic interpretations about "good" and "bad" may be inaccurate, but they do seem appropriate and convincing.

I must say, however, that even in pathology, modern medicine increasingly considers the disease to be part of our body, often leading to successful treatment not by "eradication" and "elimination" but by holistic management of a chronic condition. The case of HIV therapeutics is perhaps the brightest example of such revisionist thinking, which has transformed the disease from a "death sentence" in the early years after its discovery to a nonlethal chronic infection today.

Kostarelos then contrasts the less warlike 'modern medicine' metaphors with nanomedicine,

In nanomedicine, which is the application of nanotechnologies and nanomaterials to design medical treatments, the war imagery is even more prevalent. Two of the most clinically successful and intensively studied technologies that operate at the nanoscale are "stealth" and "targeted" medicines. "Stealth" refers to a hydrophilic (water-loving) shield built around a molecule or nanoparticle, made from polymers, that minimises its recognition by the body's defence mechanisms. "Targeting" refers to the specific binding of certain molecules (such as antibodies, peptides and others) to receptors (or other proteins) present only at the surface of diseased cells. The literature in nanomedicine is abundant with both "stealthing", "targeting" and combinations thereof.

Kostarelos then asks this question,

The question I keep asking myself since I read the article about war metaphors in nanomedicine has been whether we are using terminology in a simplistic, single-minded manner that could stifle creative and out-of-the-box thinking.

Intriguing unintended consequences, yes?

Getting back to The Scientist article, which I found quite informative and interesting, its 'war metaphors' seem to extend even to some of the artwork accompanying the article,

[downloaded from http://www.the-scientist.com/?articles.view/articleNo/40598/title/Nanomedicine/]

[downloaded from http://www.the-scientist.com/?articles.view/articleNo/40598/title/Nanomedicine/]

Is that a capsule or a bullet? Regardless, this * article provides a good overview of the research.

* The word ‘a’ was removed on Aug. 8, 2014.

Newcastle University (UK) has a PhD Studentship in Synthetic Biology and Nanotechnology available

Open to UK, European Union, and international students, the studentship deadline for applying is Aug. 18, 2014. Here’s more from the Newcastle University notice on the jobs.ac.uk website (Note: Links have been removed),

PhD Studentship in Synthetic Biology and Nanotechnology – Towards Algorithmic Living Manufacturing (TALIsMAN)

Value, Duration and Start Date of the Award
The Doctoral Training Award is for £20,000 per annum. This award covers fees and a contribution to an annual stipend (living expenses).

Three year PhD

Start date: 14 September 2014

Sponsor
Science Agriculture and Engineering Faculty Doctoral Training Awards

Project Description
The discipline of Synthetic Biology (SB), considers the cell to be a machine that can be built -from parts- in a manner similar to, e.g., electronic circuits, airplanes, etc. SB has sought to co-opt cells for nano-computation and nano-manufacturing purposes. During this scholarship programme of doctoral studies the student will pursue investigations at the interface of computing science (biodesign & biomodeling), chemical sciences (nanoparticle delivery systems), microbiology (bacterial genetic engineering) and nanoscience (DNA origami).

Name of the Supervisors
Professor Natalio Krasnogor (Lead Supervisor), School of Computing Science

Dr David Fulton, School of Chemistry

Dr Chien-Yi Chang, Centre for Bacterial Cell Biology

Person Specification and Eligibility Criteria
You must have an MSc in synthetic biology, microbiology, organic chemistry or computing science. You also should have demonstrable independent research skills, e.g. having completed a successful MSc dissertation or having a publication in a recognised peer reviewed conference or, ideally, journal. The candidate must have substantial laboratory experience and excellent programming and numeracy skills.

This award is available to UK/EU and International candidates. If English is not your first language, you must have IELTS 6.5.

Closing Date for Applications
Applications will be considered until Monday 18 August 2014. However, awards may be made to successful applicants before this date and early application is recommended.

So according to the line above, it’s better to apply sooner rather than later. Good luck!

Gold on the brain, a possible nanoparticle delivery system for drugs

A July 21, 2014 news item on Nanowerk describes special gold nanoparticles that could make drug delivery to cells easier,

A special class of tiny gold particles can easily slip through cell membranes, making them good candidates to deliver drugs directly to target cells.

A new study from MIT materials scientists reveals that these nanoparticles enter cells by taking advantage of a route normally used in vesicle-vesicle fusion, a crucial process that allows signal transmission between neurons.

A July 21, 2014 MIT (Massachusetts Institute of Technology) news release (also on EurekAlert), which originated the news item, provides more details,

The findings suggest possible strategies for designing nanoparticles — made from gold or other materials — that could get into cells even more easily.

“We’ve identified a type of mechanism that might be more prevalent than is currently known,” says Reid Van Lehn, an MIT graduate student in materials science and engineering and one of the paper’s lead authors. “By identifying this pathway for the first time it also suggests not only how to engineer this particular class of nanoparticles, but that this pathway might be active in other systems as well.”

The paper’s other lead author is Maria Ricci of École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland. The research team, led by Alfredo Alexander-Katz, an associate professor of materials science and engineering, and Francesco Stellacci from EPFL, also included scientists from the Carlos Besta Institute of Neurology in Italy and Durham University in the United Kingdom.

Most nanoparticles enter cells through endocytosis, a process that traps the particles in intracellular compartments, which can damage the cell membrane and cause cell contents to leak out. However, in 2008, Stellacci, who was then at MIT, and Darrell Irvine, a professor of materials science and engineering and of biological engineering, found that a special class of gold nanoparticles coated with a mix of molecules could enter cells without any disruption.

“Why this was happening, or how this was happening, was a complete mystery,” Van Lehn says.

Last year, Alexander-Katz, Van Lehn, Stellacci, and others discovered that the particles were somehow fusing with cell membranes and being absorbed into the cells. In their new study, they created detailed atomistic simulations to model how this happens, and performed experiments that confirmed the model’s predictions.

Gold nanoparticles used for drug delivery are usually coated with a thin layer of molecules that help tune their chemical properties. Some of these molecules, or ligands, are negatively charged and hydrophilic, while the rest are hydrophobic. The researchers found that the particles’ ability to enter cells depends on interactions between hydrophobic ligands and lipids found in the cell membrane.

Cell membranes consist of a double layer of phospholipid molecules, which have hydrophobic lipid tails and hydrophilic heads. The lipid tails face in toward each other, while the hydrophilic heads face out.

In their computer simulations, the researchers first created what they call a “perfect bilayer,” in which all of the lipid tails stay in place within the membrane. Under these conditions, the researchers found that the gold nanoparticles could not fuse with the cell membrane.

However, if the model membrane includes a “defect” — an opening through which lipid tails can slip out — nanoparticles begin to enter the membrane. When these lipid protrusions occur, the lipids and particles cling to each other because they are both hydrophobic, and the particles are engulfed by the membrane without damaging it.

In real cell membranes, these protrusions occur randomly, especially near sites where proteins are embedded in the membrane. They also occur more often in curved sections of membrane, because it’s harder for the hydrophilic heads to fully cover a curved area than a flat one, leaving gaps for the lipid tails to protrude.

“It’s a packing problem,” Alexander-Katz says. “There’s open space where tails can come out, and there will be water contact. It just makes it 100 times more probable to have one of these protrusions come out in highly curved regions of the membrane.”

This phenomenon appears to mimic a process that occurs naturally in cells — the fusion of vesicles with the cell membrane. Vesicles are small spheres of membrane-like material that carry cargo such as neurotransmitters or hormones.

The similarity between absorption of vesicles and nanoparticle entry suggests that cells where a lot of vesicle fusion naturally occurs could be good targets for drug delivery by gold nanoparticles. The researchers plan to further analyze how the composition of the membranes and the proteins embedded in them influence the absorption process in different cell types. “We want to really understand all the constraints and determine how we can best design nanoparticles to target particular cell types, or regions of a cell,” Van Lehn says.

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

Lipid tail protrusions mediate the insertion of nanoparticles into model cell membranes by Reid C. Van Lehn, Maria Ricci, Paulo H.J. Silva, Patrizia Andreozzi, Javier Reguera, Kislon Voïtchovsky, Francesco Stellacci, & Alfredo Alexander-Katz. Nature Communications 5, Article number: 4482 doi:10.1038/ncomms5482 Published 21 July 2014

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

I last featured this multi-country team’s work on gold nanoparticles in an Aug. 23, 2013 posting.