Do you think your spider silk research could eventually be strong enough to be used as a building material? Where is your research at right now?
Spider Silk is a very small material and anything that we do in making, testing or understanding materials is at an extremely small value so it’s nothing like on the scale of buildings. We’re really just trying to understand the material strengths of this material and we can make very small pieces but not much more. And of course we would take spider webs and we would sort of say you could take that natural material and use it for some kind of engineering. The threads of silk are extremely thin, they’re micrometers. You would have to assemble and do calculations on how many spider webs you would need or how many spiders you would need and you would quickly end up with millions of spiders you would need in order to actually make a real rope of the material. If you actually can make a material like this, like if you could make these quantities, it would be a very strong material and it has the potential strength of steel so you would get something that has a very high tensile strength and significantly less weight or density than steel. The ratio of strength versus density is much better in silk so you get a very light material that is as strong as steel and it is tougher to break. You can stretch silk quite a bit before it breaks and in order for it to break it requires a high amount of energy until it actually fractures. I think if you were to make something to walk on between buildings it would be potentially very shaky, like walking on a rubber band maybe.
What are other practical uses do you think could come out of your research?
I think technically we are interested in understanding in how you would make a strong material from very weak building blocks. Chemically, the silk has weak building blocks like hydrogen bonding and other silk. What we are mainly interested in is seeing how it is naturally and understand the principles of how biological organismic spiders can make material that is as strong as one of the strongest engineered materials that uses so much less energy and so much fewer resources and actually creating these materials. That’s our main understanding of the scientific impact. And then of course once we know how to do this we can say create a whole bunch of different materials; not necessarily exactly like silk but out of using the principles we see in silk so we could use plants to make very strong materials, you can use sand from the beaches to make materials but the materials that currently are considered to be weak structurally or mechanically or considered useless and somehow changing their structure at a specific scale to make them useful. And that’s really what the spider does, is it takes simple proteins and makes them into one of the strongest threads that has multiple paths with these many different dimensions. Last of all what we’re trying to do is we’re trying to translate this into something that is not exactly like spiders, we’re trying to take the principles behind that. And there’s another thing maybe in terms of what you might be interested in, structurally is there is some really interesting structures you can see at the nano scale. We have worked a lot on identifying the structure of silk and I can actually send you some images. We’ve done some rapid prototyping of silk nano structures and molecules to make them visible at larger scales. Using some of the inspiration you might see in silk, even not in the web, but really at the molecular scale to make some of the structures at the macroscopic scale. We haven’t done this, we basically study the biological, bi-chemically, material science side, but since you’re in architecture – one interesting aspect would be if you could actually create a macroscopic structure that is really related or inspired by the nano scale structure of silk.
Would you be able to apply such principles to say plastics to make them stronger?
To other materials, yeah, exactly. One of the ideas is that we can actually well yeah, we can make much stronger materials than silk if we use the right building blocks. So we can use carbon nano tubes, graphine and other materials that we have at our disposal and then now we have all these different compounds and molecule structures. Carbon nano tubes and graphine, they are really one of the stronger nano structures we have out there. We can take that and utilise this and make something much stronger, that’s one of the things that we’re working on in the lab at the moment.
What kind of aesthetic qualities do you think it would have?
The kind of materials that we’re looking at here would be extremely strong like steel or alloys and other ceramics, but they would be potentially unbreakable and they could be designed for impact so you could have materials that could withstand a lot of kinetic energy coming in such as explosions. We’re also looking at materials that could be mutateable or change during its lifetime. The materials we are looking at here are changeable so they’re not static. So today if you create a material such as concrete or steel they have certain properties and remain this way in the building. With some of the other work we do we’re designing materials that are changeable so we can use electric fields or magnetic fields or we can use light as a way of changing the material significantly and we can do this because we can really tune the nano structure of the material and molecule arrangements of the basic building blocks in such a way that at the macro scale we’d have a varied thickness and different response. What I mean is that we could have something that behaves like concrete under normal operational conditions but when there’s an earthquake we can turn this into something like elastic or something extremely stretchy. Or if there’s an explosion the building could detect the impact and would change the material from being just strong to being very tough, very condensable so the building for that moment would mitigate the huge impact of kinetic energy. That is what we do and of course it has many other applications not only in architecture and buildings but also in armour and military applications, vehicles, aircrafts, you name it. There’s a whole range of different areas where the ability to change the mechanical properties of materials becomes extremely important.
In another area, silk by itself is quite interesting. It has medical applications. Silk is a biomaterial that is bio-compatible so you can use silk during operations, you can use it for stitches and it doesn’t conflict with the natural immune system. So we can use it as a very effective biomaterial. If somehow we could figure out making silk in large quantities we can use it as ways of stitching together organs and other systems, potentially using it for tissue engineering to grow new tissue to a certain degree. So those are some of the other angles that silk could take. Silk as materials have the same building blocks as other biological tissues - the proteins, which is a huge advantage in making biomaterials rather than creating biomaterials out of polymers, which are non natural, so the body would see these polymers as the enemy and they would try to eat it up or destroy it. The silk is sort of a natural way of making biomaterials. The issue again here is that we can’t make silk in huge quantities. That’s one of the main limitations, we can’t just go out there and just take a spider web because we need to have something more reliable in quality and quantity, but that’s another angle of what we do that we pursue.
I read that there are researchers that are finding ways to farm the spider silk proteins by genetically modifying goats to produce them...
Yes, that’s right, that’s very very true. The silk protein you can make in huge quantities and you don’t actually have to use goats, there are many other ways of doing it. The goats, I think, is one of the most interesting ways to make the proteins. But the issue that remains when using these proteins is making the material because they cannot produce the kind of silk that spiders can produce naturally. It’s one of the big challenges in the field. But it is one of the possible ways of going about this, making protein building blocks in animals, bacteria or goats’ milk. So that’s definitely a very exciting direction to go. But another issue is that you make the proteins, but how do you use the proteins at a macro scale. For example you can’t just put these proteins individually hand by hand and assemble them in a way you like. It’s all done by self assembly and the way spiders make the silk is a highly complex process which we’re still understanding at this point.
How long do you think it would take before such technology takes off and becomes a mainstream resource?
The whole area of actually making materials by controlling their molecular structure and then forming some larger scaled properties from the designing phase is something that’s emerging and there is a lot of activity right now. It could be five years. There are some materials out there already that include some nano structured elements, there are some bio materials that people have been made, so that’s an example but yeah, maybe in… it’s really hard for me to say. Putting a timeframe on that is really difficult. But I think it will be driven also by the need economically. So if there is a need for new ways of making materials from natural resources like plants or a protein then the timeframe will be much shorter. But it could remain much cheaper to produce materials from oil and other resources available and then the time frame could never be determined. But there are some anxiety questions such as energy constant resources that really make people in the industry think how they can really re-engineer their resources. For example in a bunch of research projects I have with companies, they’re extremely nervous about the ability to produce things in the timeframe of five, ten, fifteen years, at the same price because energy needed to produce materials like concrete, adhesives and all these other kinds of materials you need for buildings and other industries become very expensive so they’re always trying to find ways not to buy things. Can we use fewer materials, get the things done. Can we sell the thing for the same price but then of course you’d use less material. And I think that it will be driven by the market. If there’s a strong need. We are trying to provide solutions to ideas for unconventional ways of making things, making materials, making a functional structure. But I’m not in the position to really understand the economic implications, but it will be driven by that in the end.
On being eco-friendly:
Yeah, that’s one of the main driving points I think for this. I wouldn’t necessarily put that label on it but yeah, you could call it eco-friendly if you wish, but it’s really driven by the fact that there is a limitation in resources and there are limitations to how much energy we can produce using conventional forces so there are going to be driving forces that tell industry that they could produce things maybe cheaper by making them more eco-friendly which would transfer into using resources that we currently do not use, using them more effectively.
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