2011 Fall MRS: Stiff storage

Posted on behalf of Rosamund Daw (Senior Editor, Nature)


What technological innovations will form the car of the future? Carbon fibre composites are increasingly a viable option for the structural components of next-generation cars for improved energy efficiency, particularly as their use in the aerospace industry will undoubtedly bring manufacturing costs down. Energy storage devices such as capacitors and batteries will also be the order of the day.

Milo Shaffer and colleagues at Imperial College have recognised this as an opportunity for further energy savings. Both structural re-inforcement composites and electrochemical devices rely on the use of layered architectures. So why not combine the two and incorporate energy storage into the composites which provide strength and stiffness in the body of the car? This imaginative concept, potentially offering huge weight saving was presented in the ‘Applications of Hierarchical Materials’ session at the MRS [Hierarchical composite materials for structural energy; Shaffer, M., Qian, H., Houlle, M., Amadou, J., Bismarck, A., Greenhalgh, E.; Symposium G; 2011 Fall MRS]. I think it offers a refreshingly different angle on the vast research activity going on in energy storage.

Shaffer chose supercapacitor devices which cannot store as much energy as batteries but can quickly discharge; he envisages initial applications in load levelling, rather than providing a comprehensive mobile energy supply. His group approached the problem by modifying the traditional components of composites: carbon fibre laminates act as the electrodes and the epoxy matrix of the material forms the electrolyte. Glass fibre mats acted as insulator layers. The carbon fibre laminates were activated (made porous) to maximise surface area and an ionic liquid was incorporated into the epoxy to improve ionic conductivity. Carbon nanotubes deposited on the carbon fibres simultaneously increased the surface area for further charge storage capability and interlocked with the matrix to constrain buckling — frequently a problem with composites.

Early experiments have confirmed proof of principle. In fact the stiffness of the material is impressive despite the modifications: ‘as good as it gets’ says Shaffer. But there is still some way to go to improve mechanical strength and charge storage capability. Shaffer has partnered with Volvo in an FP7 programme entitled ‘StorAGE’ in which his team has been set the task of achieving 15% of a car’s weight reduction using these multifunctional composites. The first car component to be generated will be the wheel well.

These materials could presumably be more broadly used in smaller scale mobile applications such as laptops where weight and volume are at a premium.

2011 Fall MRS: A plug for stem cells

Posted on behalf of Rosamund Daw (Senior Editor, Nature)


In the field of materials science as applied to regenerative medicine, a common theme is the design of novel scaffold materials as supports for stem cell growth and differentiation. However not all stem cell therapies use scaffolds. In some biomedical research efforts, cells are injected directly into the site of need. Such a strategy has been applied to a variety of different injuries and diseases, for example Parkinson’s disease, stroke, heart attack and spinal-cord injuries. Though the approach has had some successes, a major stumbling block has been simply the ability to deliver a payload of viable cells to the site. Sarah Heilshorn at Stanford University has been investigating how materials science can help and presented her group’s findings in the ‘Biomaterials for Tissue Regeneration’ Symposium at the Fall MRS [The design of hydrogel cell carriers to improve stem cell viability during transplantation by direct injection; Brian Aguado, Sarah Heilshorn; Symposium KK; 2011 MRS Fall Meeting].

Early in vitro model experiments surprisingly revealed that the cell injection procedure itself led to severe membrane damage and around 40% cell death. Heilshorn suggested that this cell death was the result of elongational flow at the entrance of the syringe needle, disrupting cell membranes. Her research group has been investigating how hydrogels can mechanically protect cells from damage during injection. In particular they have focused on physically-crosslinked protein hydrogels. The physical crosslinks are easily broken on the application of shear, and it is this which Heilshorn believes helps protect the cells. The hydrogel shear thins at the walls of the syringe during injection providing lubrication to allow the rest of the gel to flow as a plug through the needle rather than with the differential flows across the bore experienced by a fluid which causes the extensive cell death.

Ingeniously, the material is comprised of two components and gelation occurs on mixing. This obviates the need for one of the usual gelation ‘triggers’ such as a temperature or pH, required in a single component gel, which can also damage the cells.

Heilshorn’s group have demonstrated that human adipocyte-derived stem cells and mouse adipocyte-derived stem cells can happily proliferate and differentiate inside the hydrogels. Furthermore the hydrogels improve the retention of cells injected into a mouse model, compared to delivery in alginate, saline or collagen. Adipocyte- or fat-derived stem cells are easily harvested from patients and are likely to be one of the first stem cell types to be used routinely in the clinic.

I shall look forward to the next chapter in the story, to find out if the hydrogels offer enhanced therapeutic capability.

Reactions – Dave Winkler

Dave Winkler is at CSIRO Materials Science & Engineering in Clayton, Australia, and works on theoretical and computational chemistry and complex systems science.

1. What made you want to be a chemist?

I was always fascinated with how things worked, deciphering their components and interactions that produce an emergent system behaviour or property. I had a home chemistry lab behind the garage when I was young.

2. If you weren’t a chemist and could do any other job, what would it be – and why?

Tough choice, but probably a psychoanalyst or medical specialist. The human body, particularly the human mind, is so incredibly complex there are more than enough great problems for study for the foreseeable future.

3. What are you working on now, and where do you hope it will lead?

Two main areas: understanding the molecular basis for control of stem cell fate and design of small molecules that achieve this; modelling the properties (especially biological effects) of nanomaterials and materials more generally to allow design, optimization and safety.

4. Which historical figure would you most like to have dinner with – and why?

Having read Bill Bryson’s A Short History of Nearly Everything I realise that some of the scientific greats may not have been good dinner conversationalists. I would choose Leonardo da Vinci because of his brilliant mind a breadth of his scientific and artistic interests.

5. When was the last time you did an experiment in the lab – and what was it?

I do computational experiments every day. The last time I was in an experimental lab was to learn to culture embryonic stem cells, about four years ago.

6. If exiled on a desert island, what one book and one music album would you take with you?

Excluding obvious must have books like the Bible, I would choose Caravans by James A Mitchener (one of the great travel sagas), or collected works of Tolstoy. For music either a great blues compilation, or Mozart.

7. Which chemist would you like to see interviewed on Reactions – and why?

George Whitesides, I love the way he thinks so laterally, and the broad range of areas of chemistry he has contributed to.

Fall MRS Meeting 2011: Analogies, highlights and trivia

I’ve spent the last week in, as Ros Daw described on Wednesday, a relatively balmy Boston, mooching around the halls of the Hynes Convention Center and the Sheraton diving in to whichever session of the Materials Research Society meeting took my fancy. Unfortunately, there’s now a very cold bite to the air in New England but thankfully I’m on my way home to the Old England.

It was my first MRS meeting but, being a bit of an ACS meeting veteran, I was expecting something very similar to that but smaller, like an MRS slider to the ACS Big Mac, if you will. And that’s exactly what I found: you have a convention center with lots of parallel sessions, a nearby hotel housing some more sessions, and an Exhibition Hall with lots of people trying to sell stuff. But (dropping the burger analogy for a scientific one), like the nanomaterials discussed in many of the sessions this week, because of confinement effects, the properties of a meeting are not linearly related to their size.

With a smaller meeting (6000 attendees rather than >10,000 seen at ACS meetings) comes the benefit of a smaller meeting space, which leads to a much more ‘intimate’ event. Intimate is probably not the right word with 6000 people involved but if you know someone here then you’re very likely to see them, which in my experience is not how something of the size of the ACS meeting works. It also makes it far easier to go to numerous sessions on a given morning or afternoon, which, given the diverse interests of academics these days, is a big benefit. So I think that this is a perfectly-sized meeting and I gather from the attendees that I met, who keep coming back, that they do too.

There have been a few highlights for me over the week. The symposium on ‘Organic photovoltaic devices’ was my default pick for whenever I was unsure where to go, I was always likely to find something to hold my interest there.

During the meeting, Z.L. Wang (Georgia Tech) received a MRS medal for his work on ZnO nanomaterials, and therefore gave an associated presentation. The goal of much of his ZnO nanowire research is to harvest mechanical energy. Therefore when we do stuff — walk around, work out, move our fingers to play sports games on Xbox — those movements could be used to generate enough power to charge your iPhone or any other portable device. The nanowires are piezoelectric; that is, they generate a voltage when they are bent, and Wang has been working towards improving their efficiency to make them viable for various industrial applications.

This week I saw another take on the same problem when Tom Krupenkin from the University of Wisconsin-Madison discussed his recent work (published in Nature Communications) on using ‘reverse electrowetting’ to harvest energy. At this point I was going to give you a lovely description of how it works, but it seems Katharine Sanderson has already done it over at Nature News. So very briefly, a conductive liquid, if placed on an electrode, can be deformed by charging the electrode surface. This improves the electrode’s wettability and allows the droplet to spread out better. This can also be done in reverse: if you are able to physically deform a droplet on the surface of an electrode (by movement), you can create a charge and thus power. Krupenkin was able to apply this principal to an array of 150 droplets and talked about the possibility of placing such generators in to the heels of shoes. It was a nice talk and I recommend reading more at Nature News and Nature Communications.

I also enjoyed the presentation given by Paul Alivisatos very much. His talk was to celebrate his Von Hippel Award, the highest honour at the MRS society and was nicely balanced between anecdote and cutting-edge science. As a student at the turn of the century working on a completely different topic, I wasn’t particularly aware of the synthetic work of Alivisatos, but that soon changed when I started working for the Journal of Materials Chemistry at the Royal Society of Chemistry; every other paper I read involved the synthesis of nanoparticles, with chemists showing how it was possible to control their size or shape. Given that that was my introduction to the field and that now you can dial up many different structures and sizes, it was nice to go back to the beginning and hear a few tales from when it wasn’t quite so easy (Alivisatos was actually warned off working with them by a theorist colleague!).

And so my one bit of chemistry trivia to give you all comes from Alivisatos. So you know those ‘nanocrystal molecules’ that Alivisatos and his colleagues made by joining nanoparticles together using DNA links? You know whose idea the DNA was? No? Well it was Stanley Miller, of origin of life/amino acid fame! Alivisatos was asked to give a talk by UC Irvine students with the theme “what would you like to be able to do but can’t”. He mentioned the idea of linking nanoparticles together and that they were working on some organic compounds to do just that. Miller was in the audience and apparently put his hand up and said they should try DNA, the rest, as they say, is history. I just looked at the Letter in Nature and there is indeed an acknowledgment to S. Miller.

It might be a little too soon for me to go to the San Fran MRS meeting next Spring but I’ll certainly be thinking about returning next Fall.

Gavin

Gavin Armstrong

Senior Editor

Nature Chemistry

Fall MRS Meeting 2011: Bioinspired energy efficiency

Posted on behalf of Rosamund Daw (Senior Editor, Nature)


At the Fall MRS meeting this year we are enjoying unusually mild weather. I can remember Christmassy snow at MRS’s past where woolly hats were a must. This year, many of the attendees are wandering around without coats and I have even spotted one or two brave individuals wearing T-shirts.

Two major themes at this year’s meeting are energy and the interface of materials with biology and medicine. An intriguing presentation from Philseok Kim on Monday combined these themes in a talk describing a bio-inspired approach to improve the energy efficiency of buildings. [Adaptive and dynamic optical materials for improving energy efficiency of buildings; Kim, P., Kolle, M., Khan, M., Zarzar, L.D., Aizenberg, J.; Symposium V (Multifunctional Polymer-based Materials); 2011 MRS Fall Meeting].

Kim reflected on the concerted motion of cilia in lungs, and other hairy or high-aspect-ratio biological structures which respond and adapt to different environments. He has designed a biomimetic system in which polymeric ‘hairs’ are embedded in a hydrogel. The hydrogels can elicit a tunable response to a variety of stimuli, for example temperature, causing the hairs to stand on end or lie flat against their substrate.

Kim proposed that these structures could be used to improve the energy efficiency of buildings. Extended transparent arrays of hairs could be arranged in panels across windows. Once the temperature outside dropped to a certain level, changes in the molecular conformation of the hydrogels would stimulate the hairs to stand on end simultaneously mobilising an array of deformable micromirrors attached to their ends into a single flat panel to control light transmission, reflection and thermal gain.

I like the work because it applies biomimetics in a rather unexpected way. The final goal offers engineering challenges because effects on the molecular scale are used to elicit functionality on the metre scale. Still, if achieved, such ‘smart curtains’ could reduce need for energy-intensive heating and cooling of buildings.

Speaking Frankly: Steve Jobs and innovation

Frank Leibfarth is a graduate student trying to make his way through the academic maze. Find him contributing to the Sceptical Chymist or continue the conversation on Twitter @Frank_Leibfarth.


The premature passing of Steve Jobs has shaken the international community. Known as perhaps the greatest innovator of his generation, Jobs took Apple from bankruptcy to make it the largest company in the world, surpassing (briefly) even natural-resource giants like Exxon Mobil. The media coverage of Jobs’ death has been intense, culminating in the publication of the much-anticipated biography by Walter Isaacson. Through these numerous homages, we have gotten a sense of not only Jobs’ fierce competitiveness and intense leadership style, but also the motivations and inspirations which influenced him.

For all of Jobs’ extraordinary vision, however, almost every remembrance reiterates the fact that Jobs did not ‘invent’ anything. There were MP3 players before the iPod, smartphones before the iPhone (sorry Blackberry), tablets before the iPad, laptops before the MacBook Air; Jobs even took the idea for the graphical interface from Intel. These biographers and journalists, even those in Science, are missing the point. Jobs was revolutionary, he recognized opportunity where others failed, thought about how people will use the products not just what products they use and, in perhaps his biggest coup d’état (as I sit watching my mom shuffle between her iPhone and iPad), he made technology products so intuitive that they are even accessible to the baby boomers.

Jobs was our generation’s disruptive innovator, so why the criticism about his lack of ‘inventions’? In the technology field, perhaps more than anywhere else, the scientific process is on display for the world to see. Hypotheses are made, products developed, revaluated, and improved. Steve Jobs, like great scientists, had the vision to leapfrog the competition, pulling his field forward with each project he completed. Similar to science, Jobs’ brand of innovation did not happen in a vacuum. Popular culture makes lists of the ‘The Top 10 Inventors’, heralding the individual contributions of scientists and engineers, but it neglects the massive amount of time, talent, and manpower that went into disruptive innovations. Instead of talking about the iPod’s precursors as the true ‘invention,’ we should be focusing on the unparalleled superiority of the first iPod in comparison, where Steve Jobs introduced so many innovations that other manufacturers still haven’t caught up.

We as scientists understand the process of innovation. We have built an entire international discipline where the sharing of information in publications is prized and innovation credits both the innovator and those who inspired her/him. Listen to the science Nobel Prize speeches and hear the dozens of people each laureate mentions who were the inspiration for the work or collaborated to do much of it.

Understanding that innovation is the product of talented people working collectively should be self-evident. This is why countries fund basic research, because the innovations that eventually generate economic and social value are not the product of one ‘genius’. The perception that great discoveries and/or products are the product of mythical savant-like individuals flies against the foundations of the scientific process. Further, a general belief that we are waiting for those Jobs-like individuals gives governments an excuse to cut funding for basic research. We, as aspiring innovators, need to celebrate Steve Jobs for his unparalleled accomplishments and use his example as a reason to celebrate the scientific process.

Blogroll: Trouble brewing

[As mentioned in this post, we’re posting the monthly blogroll column here on the Sceptical Chymist. This is December’s article]

An oral history of pharma layoffs, the wonders of beer and some embarrassing artwork.

What do chemists do after they’ve just been laid off from their job in the pharmaceutical/chemical industry? Chemjobber is trying to gather useful information from people who have been through redundancy to “hear as much advice as possible for people who will be laid off”. Since the Layoff Project launch in mid-October, at the time of writing Chemjobber has been contacted by six people willing to tell their story. These have ranged from someone with 30 years’ experience to someone ‘freshly out of school’, and from someone clearly having an understandably tough time adjusting to life without “being able to discuss chemistry” to someone whose personal circumstances changed so drastically they could easily put the loss of work into perspective.

Wort. Mash. India pale ale. German wheat beer. You probably expect to see words like these in a blog post about beer, but how about gibberellic acid, enzyme inactivation, dextrin oligomers (with structures!) and isomerization? Regular Blogroll readers won’t be surprised to learn that the blogpost in question is by Martin Lersch, of Khymos. In his ~2,500 word post ‘Wonders of extraction: Brewing beer’, he takes readers through a thorough look at the first two steps of brewing beer: mashing and wort boiling. In his words, these “are really quite sophisticated extractions”.

And finally…what better way to decorate a new chemistry lab than to frost some pictures of molecules onto the glass doors, and onto a funky yellow glass artwork? Well, if you go ahead and decide to decorate your lab with molecular structures, perhaps you should check out at ChemBark what happened when Georgia Tech did this. If you don’t like five-valent carbon or triply bonded bridge head atoms on fused rings, you have been warned!

Reactions – Anders Østergaard Madsen

Anders Østergaard Madsen is in the Department of Chemistry at the University of Copenhagen, and works on crystal engineering using crystallographic techniques and computational approaches in the study of polymorphic molecular crystals.

1. What made you want to be a chemist?

It was not until my final high school year that I realized science was more interesting than art and literature. In fact, I did not fully understand chemistry in high school, and this annoyed me so much that I fought courageously to understand it. Do I understand chemistry today? Only vaguely – there are, fortunately, still vast amounts of uncharted territory to explore.

2. If you weren’t a chemist and could do any other job, what would it be – and why?

I would be physician; I admire these people who every day take responsibility for the health and life of other people.

3. What are you working on now, and where do you hope it will lead?

I am studying the stability and formation of polymorphic molecular crystals. Understanding the mechanisms behind the self-assembly and stability of solid-state materials at the molecular level is fundamental research – but with wide applications for design and manufacture of materials.

4. Which historical figure would you most like to have dinner with – and why?

There are so many! To mention one, I would like to have dinner with Tycho Brahe (1546-1601) – a Danish astronomer, and a leading figure of the scientific revolution. Tycho Brahe is credited with the most accurate astronomical observations of his time, and his data were used by Johannes Kepler, to derive the laws of planetary motion, one of the foundations for Isaac Newton’s theory of universal gravitation.

I have spent many holidays on the island Hven, where Tycho Brahe made his famous astronomical observations. Tycho was a very colorful person himself, and lived in a very important flourishing period of Danish history.

5. When was the last time you did an experiment in the lab – and what was it?

The last thing I did in the lab was to perform a very meticulous X-ray diffraction single crystal measurement. I like to do very precise and redundant measurements. A saying goes that “Theory is a good thing, but a good experiment lasts forever!”

6. If exiled on a desert island, what one book and one music album would you take with you?

I might stay for a long time on that desert island, so I have to bring something that will keep me thinking …. The collected works of Søren Kirkegaard would do. And a Bob Dylan music album… Blonde on Blonde (1966), thank you!

7. Which chemist would you like to see interviewed on Reactions – and why?

I have had the opportunity to collaborate with Professor David Eisenberg from UCLA. He is a very inspiring person with a knowledge that reaches far beyond chemistry. I am sure he would give some very interesting answers.

Reactions – David Lindsay

David Lindsay is in the School of Chemistry at the University of Glasgow, UK, and works on the synthesis, structure and reactivity of N-heterocyclic carbene-main group complexes, with a particular interest in developing main group-NHC complexes for new applications in organic synthesis.

1. What made you want to be a chemist?

I enjoyed organic chemistry at school. I liked the order in the subject; the homologous series of alkanes and alkenes, the nomenclature for different functional groups, the way you could represent molecules on paper. I was fascinated by the power organic chemistry gave you to create new molecules. And I had brilliant teachers – they gave me the freedom to explore the subject, they answered every question I had and were always encouraging.

2. If you weren’t a chemist and could do any other job, what would it be – and why?

I would probably like to be a sports scientist and endurance sports coach. That way I would still be able to do research, indulge my inner geek in the scientific aspects of performance, and contribute to the growth and development of those I coached, and share in their successes – essentially, all the best aspects of an academic job.

3. What are you working on now, and where do you hope it will lead?

My research is focussed on the field of N-heterocyclic carbene complexes of main group elements; mostly boron at the moment. I hope the research will lead in many different directions, including using the complexes as catalysts, and maybe even in medicine. However, in such a new and relatively unexplored field, fundamental structure and reactivity studies are also very important, and we hope to make a contribution here as well.

4. Which historical figure would you most like to have dinner with – and why?

I think the 1965 Nobel Prize dinner would have been fun – RB Woodward and Richard Feynman were both fascinating characters. But I think I would choose Richard Feynman if I could have only one guest.

5. When was the last time you did an experiment in the lab – and what was it?

I work in the lab a lot these days. The last reaction I did was the synthesis of an imidazolium salt, which will be used to form an NHC-borane complex.

6. If exiled on a desert island, what one book and one music album would you take with you?

Music album would be “The First Circle” by the Pat Metheny Group. Once you get past the comedy first track, it’s a brilliant album which loosely falls into the jazz category. The book I would take is “Underworld” by Don DeLillo. It’s a tour through American history from the beginning of the cold war to end of the 20th century, told through a mix of fictional and fictionalised historical characters, and their reaction to events like the Cuban Missile Crisis and Kennedy’s assassination. If I could cheat and have two books, I’d take also take “Earthly Powers” by Anthony Burgess.

7. Which chemist would you like to see interviewed on Reactions – and why?

Kevin Booker-Milburn, one of my old colleagues at Bristol, just to see him struggle to reduce his music collection down to one album.

Element of the month: Meteoric calcium

Calcium is one of the most abundant elements on Earth. It plays various roles in many organisms, whether for the contraction of muscle cells, preserving potential differences across membranes, as a co-factor for some enzymes, or a component of bones and shells, to name a few.

Yet, it is surprisingly scarce in the upper atmosphere. Why could that be? Don’t anxiously skip to the end of this post for the answer… this scarcity remains unexplained for now. In this month’s ‘in your element’ article (subscription required) John Plane, Professor of Atmospheric Chemistry at the University of Leeds, ponders on this mystery.

All of the calcium that is present in the upper atmosphere has actually been brought there by interplanetary dust particles entering the Earth’s atmosphere, in a process called ‘meteoric ablation’. The intriguing data is that the concentration of calcium is much lower than expected — about 200 times lower than that of sodium for example, whereas they are present in roughly the same concentrations in the Earth’s crust. Check out the article to find out how scientists measure metal concentrations in the atmosphere.

Could the interplanetary dust particles be depleted in calcium before they even come in contact with our atmosphere? Could it be that more volatile elements (such as sodium) get ablated from the meteorites much more easily than calcium? Or an effect of a peculiar atmospheric reactivity for calcium? Plane explains how some of these reasons are valid, but only to some extent — and so the depletion in calcium has not yet been entirely accounted for.

Anne

Anne Pichon (Associate Editor, Nature Chemistry)