Blog @ NanoVic - Nanotechnology Blog

Eric Isaacs (Argonne National Laboratories, USA) got our brains ticking over at ICONN2008 with his presentation on the role of nanotechnology in energy creation. While we all know that solar energy is greatly underutilised, the problem is that currently its mode of collection is very inefficient - the best on record is 32% efficiency (at least 50% efficiency would be viable). In addition, solar energy is difficult to store. Using solar energy is therefore very expensive compared to more traditional sources of energy, such as petroleum. The Argonne National Laboratory is currently focussing on 3 main areas to improve the use of solar as an energy source:

1. photovoltaics (such as the use of nanobiohybrids for solar electric conversion);
2. solar fuel (exemplified by artificial photosynthesis);
3. solar thermal (by way of self-assembled nanoparticles).

Interestingly, Isaacs commented that unlike in the past, when companies like Bell Labs (where Isaacs was a past employee) were the primary drivers of socially-beneficial invention, these days the engine for fundamental innovation needs to come from a multi-tiered approach involving academia (ie government labs using tax-payers money), small business and medium-large scale industry. The challenge as I see it is to get all these groups aware of each other, and to work together to allow such collaborations to happen. Networking at conferences such as ICONN can only promote such opportunities. Entities such as Nanovic are also critical.

Ipod may have called one of their models nano, but truly nano-sized radios have been tipped as one of the 10 emerging technologies of 2008. 

A nano radio consists of a single molecule (a carbon nanotube) which can receive radio signals.  The radio works by translating the electromagnetic oscillations of a radio wave into the mechanical vibrations of a nanotube, which are in turn converted into a stream of electrical pulses that reproduce the original radio signal.  Of course this means that the first transmission it was successfully tested with was ‘Good Vibrations’ by the Beach Boys.

 The nano radio could be incorporated into tiny wireless devices, or even used in medicine to travel around the body, responding to radio signals, perhaps delivering drugs to targeted areas. 

 In breaking news….I stand here at the ICONN2008 internet cafe filled with new knowledge and great excitement regarding recent developments in nanotechnology. One of the hottest topics at the conference so far is the use of nanotechnology for energy generation and storage. A presentation by Micheal Gratzel (Ecole Polytechnique Federal de Lausanne, Switzerland) this morning was particularly relevant. In solving the world’s energy crisis, Michael really got down to the main point in his statement that “nanotechnology is a powerful tool to get the right molecular architecture for power generation and storage”. What he means is that nanotechnology allows humans to design and create new structures to separate charge (ie separate photons from electrons) and store that energy potential in batteries. That’s what power is all about. It’s inspiring stuff. More soon!

A gecko-inspired medical adhesive may have potential applications for sealing wounds and for replacement or augmentation of sutures or staples. 

US researchers have used a polymer poly(glycerol-co-sebacate acrylate) and modified the surface to mimic the nanotopography of gecko feet, which allows attachment to vertical surfaces.  Ideally these adhesives would also have the ability to deliver drugs or growth factors to promote healing.  The findings have been published in Proceedings of the National Academy of Sciences.

As a first demonstration, a gecko-inspired tissue adhesive from a biocompatible and biodegradable elastomer combined with a thin tissue-reactive biocompatible surface coating was been created. Tissue adhesion was optimized by varying dimensions of the nanoscale pillars, including the ratio of tip diameter to pitch and the ratio of tip diameter to base diameter. Coating these nanomolded pillars of biodegradable elastomers with a thin layer of oxidized dextran significantly increased the interfacial adhesion strength on porcine intestine tissue in vitro and in the rat abdominal subfascial in vivo environment.

Perhaps this might also lead to taking the ‘ouch’ out of removing bandaids from the skin!

Researchers at Victoria’s Monash University have found a way to coat fibres with titanium dioxide nanocrystals, which break down food and dirt in sunlight, making natural fibres such as wool, silk, and hemp that will automatically remove food, grime, and even red-wine stains when exposed to sunlight.

Fibres are coated with a thin, invisible layer of titanium dioxide nanoparticles, four to five nanometers in size. Titanium dioxide, which is used in sunscreens, toothpaste, and paint, is a strong photocatalyst: in the presence of ultraviolet light and water vapour, it forms hydroxyl radicals, which oxidize, or decompose, organic matter. These nanocrystals however, cannot decompose wool and are harmless to skin, and moreover, the coating does not change the look and feel of the fabric.

Titanium dioxide can also destroy pathogens such as bacteria in the presence of sunlight by breaking down the cell walls of the microorganisms, which could make self-cleaning fabrics especially useful in hospitals and other medical settings.

It’s one of those everyday annoyances, finding yourself with a flat battery in any one of the gadgets we carry around constantly now.  I would love the option of charging your phone or your ipod while you’re out and about.  And it looks like that may be possible soon, with a recent report in Nature on power production from nanotextiles (watch me carefully avoid the use of the pun ‘power dressing’!)

 The textiles consist of zinc oxide nanowires which generate electricity by the piezoelectric effect, in other words, produce electricity when under mechanical stress.  The zinc oxide nanowires are embedded around a Kevlar fibre to produce something looking like a bottle-brush.   Some are then coated in a nanolayer of gold, to act as an electrode. These are aligned and the ‘bristles’ rub past each other, creating the electrical current (see picture).   Once optimised, this nanotextile should provide a simple and cheap way to convert energy of walking into electrical energy.  This report follows an earlier report of a knee brace designed to harvest energy from walking.    Maybe one day we will be able to throw our old chargers out and simply plug in and go for a stroll!

I always like seeing what products are around using nanotechnology. This one caught my eye - laser safety goggles with an anti-fog insert which avoids fogging even “under extreme conditions”. It even claims you could take them jogging although I think one might look a bit silly running around in safety goggles!

The anti-fog insert is a plastic sheet coated with nanoparticles that absorbs humidity and avoids saturation of the air with water vapour. Consequently, a sequestration of water and therewith a fogging of the goggle is impossible.

I wonder if these inserts would work on normal glasses? I always have trouble when opening the hot oven as my glasses fog up and I can’t see. This makes life a little dangerous especially when carrying a hot roast! Perhaps it might be easier to make glass lenses incorporating this feature - may be there are some already out there? Another great feature would be lenses that repelled water as it is a little difficult to see in the rain - guess I don’t ask for much!

Despite its beautiful, floating appearance in the narrow walkways of your garden, spider silk is stronger than steel and can be extended 30-50% of its length before it breaks.  Unraveling the secrets behind the strength of spider silk is attracting a lot of research dollars - if we could replicate it synthetically, imagine the impact on fabric technology, tethering equipment and load-bearing materials.  As reported recently in Science Daily, the eternal question of how spider silk manages to be such an amazing natural substance is being tackled by researchers in Civil and Environmental Engineering at Massachusetts Institute of Technology, USA.  The group has recently published some interesting data.  Crazily enough, it apparently all boils down to the basic hydrogen bond.  Along the length of the spider silk, groups of 3-4 hydrogen bonds form nanocomposite structures within the protein assembly, binding together repeated stacks of short protein beta strands.  Overall, hydrogen bonds arranged in such groupings of 3-4 resist force and dissipate energy; any fewer bonds, and the silk is not strong enough. Any more, and there is no net gain in strength. This incredible arrangement of beta sheets and hydrogen bonds is also found in muscle tissue and amyloid fibres, suggesting that increasing protein strength by this method offered a distinct evolutionary advantage (evolution is my favourite topic at the moment). So next time you stumble through a web, and maniacally tear at your web-infested hair in utter panic, just spare a thought for the humble hydrogen bond and evolution. I know I will.

More awesome science videos, thanks to electromagnetism! Diamagnetism is a weak repelling force from an externally applied magnetic field. All materials are inherently diamagnetic. You and I are diamagnets. What happens when you put a diamagnet in a magnetic field? Well, not much. Diamagnetism is a very weak force (millions of times weaker than ferromagnetism). Unless that magnetic field is extremely strong, say 16 tesla (the earths magnetic field is approximately 50 micro tesla). Then cool things happen. Diamagnetic levitation! Behold flying frogs!

Of course much of nano is organic in the chemical sense, but now it’s deemed not to be in the way that most people associate the word.  The British Soil Association certifies things as being ‘organic’ in the UK.  It is an increasingly valuable label for products as consumers are increasingly concerned about the ethical and environmental consequences of their purchases, are prepared to pay a premium for organic.   

The soil association are the first regulating body to ban nanoparticles, in line with their ethos of ‘protecting human health’.  The ban will apply to health and beauty products and also food and technology.

Whilst they admit that nanotechnology may have enormous benefits they maintain that currently there is not enough known about their safety, drawing the comparison to GM foods.  Policy manager Gundula Azeez said, ‘As we saw with GM, the government is ignoring the initial indications of risk and giving the benefit of the doubt to commercial interest rather than the protection of human health.’  This is a worry given the enormous backlash that GM faced.  I hope that nanotechnology will benefit from a scientific community that has learned from the mistakes of the past and know that firstly thorough research into health and safety, but also public engagement, honesty and transparency, and a healthy debate about the implications is the best way to avoid the marketing nightmare that occurred with GM food.