Meet the panel: brains and concrete

It's time for a science show and tell! Chris Smith met Cambridge University cognitive neuroscientist Duncan Astle, Cambridge University food security expert Nadia Radzman,  Cambridge University engineer Livia Souza and tech expert Peter Cowley...

Chris -  Now with me to tackle the questions this week are; Duncan Astle who's a cognitive neuroscientist at Cambridge University. And sitting in front of him is something very interesting. What have you go there Duncan?

Duncan - It is. Let me describe it to you. So it looks like a tiny sculpture of a brain.

Chris - It looks like a truffle.

Duncan - It might look like a truffle, or maybe a walnut.

Chris - Yeah.

Duncan - It's around an inch and a half long, about an inch wide. It weighs, I’m going to hand it to the person next to me who's going to hold it. So it looks like a tiny sculpture but actually it's not. It's a real 3D printed brain.

Chris - Of what?

Duncan - That's the brain of one of the research fellows in my lab.

Chris - Is it really that small?

Duncan - It's life size! No, it’s not life size. I've made that joke to him many times.

Chris - What's his or her name?

Duncan - So it’s Edwin's brain

Chris - It’s as well endowed then, Edwin isn't he, cognitively speaking at least?

Duncan - He's a smart guy. Now this is actually, it would need to be about three and a half times larger.

Chris - Yeah

Duncan - For it to be his real brain. Now it's quite heavy because it's made from a steel and bronze alloy. We took a magnetic resonance imaging scan, in our department, of his brain. We have those from everyone in the lab, and then there's a company that you can send them off to and they will render it for you, and then they will print it for you in different types of substance.

Chris - Are you saying you've got this for everyone in the lab? Is this an inclusion criteria to work in your group then you have to have your brain scanned and then and then a 3D model made just to make sure you've got one.

Duncan - It's more of an inclusion criteria that they are willing to be involved in all the research experiments that we do and as a result we end up having lots of brain scans for all the lab members.

Chris - It's interesting that you're saying this though because there is a serious side to all this, isn't there? The fact that previously to study neuroanatomy you'd have to get the brain out of something, and now we're in a position where the scans are so good, like the one that presumably led to the creation of that model, that you can get the brain out of something without actually having to take its brain out. And then you can study these things in front of you, without having to harm anything.

Duncan - Yeah, it's basically been revolutionary in how we think about the brain and how we study it. So this is taken from an image from a three tesla scanner. So that's the strength of the magnet that's been used, but in Cambridge here we actually have a seven tesla scanner, so that's got an exceptionally powerful magnet. And that means that the detail with which you can look at the brain neuroanatomy, is getting increasingly sophisticated. So for instance, with the seven tesla, people are even starting to think that you might be able to look at different layers of cells within the brain. It's that sophisticated.

Chris - That's amazing thank you Duncan for introducing us to that. Now, I'm always worried when I see a falcon tube. These are the kinds of things you pee into when the doctor says give me a specimen, pee into this. But I'm sure Nadia Radzman who is a food security and plant scientist specialist from Cambridge University, that's not why you brought in that red top tube, what’s in there? to you.

Nadia - No, these are the seeds of a plant called medicago truncatula.

Chris - Medicago?

Nadia - Yes. So it's a model legume that we use in the lab to study nodule formation, and these nodules are formed in the roots, well on the roots, and they are globalist structure. They are formed with the association with soil bacteria. So the soil bacteria will be housed inside these nodules, while the bacteria would fix nitrogen from the air and form ammonium, which is available to the plant and the plants will give carbon as nutrients to the bacteria. So it's a win win situation.

Chris - So it's an exchange?

Nadia - Yes.

Chris - So the plants grow these nodules, make a home with food on tap for microorganisms and the microbes are recruited into these nodules where they bring the biochemistry that says I can grab nitrogen out of the air and make it available to you as a plant, and only for fertiliser.
Nadia - So they're pretty much, like mini-factories, mini nitrogen fertiliser factories for the plants.

Chris - Why are you studying this? I mean, is your vision that if we can work out how one group of plants that we don't want to eat, or don't want are we all the time do this, could we make plants that we do want to eat a lot more do it too, and then we wouldn't need fertiliser.

Nadia - Yes so the lab that I belong to, we want to know how legumes actually form these nodules, and if we know the exact process, this is how this is being done, then we could potentially transfer it to something like wheat.

Chris - And that would be important because at the moment we're dumping enormous amounts of fertilisers onto fields to feed a burgeoning world population, and that if we didn't have fertiliser there's no way the world could feed itself. It's fair to say that isn't it?

Nadia - Yeah. And so this is something that is interesting too. So legumes can form these nodules, and fix nitrogen at ambient temperature but if we were to produce nitrogen fertilisers, we need to have high temperature and high pressure. So that would cause a lot of fossil fuels to do that.

Chris - So it's got a big carbon footprint hasn't it? Thanks Nadia. So you can appreciate now where the food security angle comes in. Now next to Nadia is program regular, tech expert - texpert, I suppose you could say, and angel investor Peter Cowley. Now he always brings in fancy gadgets and he refused to tell us what the fancy gadget he was going to reveal is, when he said I'm going to bring in something that's going to wow you out. So what have you got?

Peter - Yeah well I've got it in front of me, I better describe it first. I've often taken it along to dinner parties and ask people what it is. You can see it in the studio. It's about a cubic centimeter, it's about one and a half centimetres long by about 7.5 millimetres by five millimeters. And it's made, it’s a little piece of ceramic, it's got about 100 ceramic pyramids inside it. This isn't helping at all is it?

Chris - Not really.

Peter - it looks like it's got burnt which is a good reason. Now you've got to cast your mind back to, and there won't be many listeners could remember this, but the V1 bombs in the Second World War, which used to fly over us stop, that sound went off and they would crash and there were many many casualties because of that. That was a pulse jet engine. So it was basically like an organ tube where it was igniting, and the gases they expelled pull the next fuel in, which ignited and so on, and that was running through about 40 or 50 hertz. This is ultrasonic apparently. So this is running at 30 kilohertz.

Chris - and what's in that? Are you saying that's a mini rocket engine?

Peter - Exactly. Yes. So its inventor is a guy called Bill Den in Great Shelford, just south of Cambridge, about five miles from Cambridge. And he does it in his shed, and I nearly invested in it in 2012. His main problem, I've got actually the final report in front of me, was igniting it, but I've been in that shed more than once, where he has ignited it. A complicated method.

Chris - So you squirt in there, fuel and air?

Peter - Yes, and what happened, is his calculations are, that it's the equivalent of a two litre car engine but double the efficiency. It’s just mind boggling.

Chris - It's just how do you extract the energy? It's just the gas stream emerging at extremely high speed, and that’s thrust?

Peter - It’s thrust. It’s a jet engine, exactly.

Chris - Goodness. And has it gone anywhere?

Peter - I don't think so. I don't think it’s gone through. I checked the company’s house and the company’s dormant at the moment. So the idea behind it, which the application’s the interesting thing, is things like putting a jet engine on the trailing edge of an aircraft wing so you haven't got that thing. So it's just basically a line of these. Got a longer one here which is probably equivalent with six litre petrol engine, which is about three centimetres long. The fluid dynamics possibly doesn't work, because the molecules size, if you think you've got fuel and air molecules are a certain size. How can you get those down to that size, but then you have seen it producing thrust, he ignited it rather clumsily but it was it was taking I think, propane gas in, and generating thrust which you could see. So that's what I brought in because it's just amazing. But we hope certain people like Hermann Hauser, who a name you might know from Cambridge who invested in but I didn’t, how it went.

Chris - We’ll have to get Hermann on, and ask how it went. I mean Duncan's impressed.

Duncan - It's basically like a tiny Lego box.

Chris - Yeah. It's a good way of putting it. It's very very smart to think that could do a two litre engine. It’s amazing.

Peter - We ought to tweet a photograph of it.

Chris - Thank you for bringing it in Peter, now sitting next to me, is Lívia Souza and now she's a civil engineer. She's also a chemist by original training. She's part of a group at the University of Cambridge who are developing self healing concrete, sounds extraordinary, why do we need self healing concrete and how does this work?

Lívia - Yeah, we need it because well there is a lot of CO2 emissions associated with the repair and maintenance of the concrete structures that we have nowadays. So the idea is, when there is a crack in concrete, what if the crack can repair itself without any external intervention, and to do so what we do is-

Chris - Oh this is where your show and tell comes and you've got what looks like a blood sample in front of you, a big pot of something! What on Earth is in that pot? It looks like jelly

Lívia - Because it's red! Here are micro-capsules. They are in liquid because they have this very interesting property that when they are wet they are very ductile. They are very soft and rubbery and when they are dry they are very brittle. So we use this as a property, for we can mix these micro capsules with concrete very easily and they are very rubbery.

Chris -This is when you're making the concrete, when it’s liquid, so you’d mix some of that in at the time when you’re making the concrete?

Lívia - Yeah, and it's worth mentioning that they are very tiny. While these ones are a bit larger so you can see them, basically, but the ones that we are actually producing in the lab are very very tiny, 100 microns, 200 microns, of size

Chris - So that's a tenth of a millimetre to a fifth of a millimetre, so very very tiny these capsules. What's in the capsules? What's the chemistry here?

Lívia - So the idea is we mix them with concrete and then when the concrete settles and dry and when there is a crack in the concrete, the crack opens the capsule and releases the healing agent.

Chris - And what’s the healing agent? What’s in there?

Lívia -  This healing agent can be a polymeric material like epoxy for instance, or it could be a mineral such as sodium silicate, or colloidal silica that can form a healing product or interestingly it can be bacteria.

Chris - The thing is, this is gonna be great for concrete we’re laying now. But obviously for the buildings that are already up there. Not so good. Or can you inject this into already injured concrete and get it to heal there?

Lívia - The technology is so recent and so interesting that we are thinking about ways of using it, and one way is to repair the structures that are already existent. A good example, it's a case in the Netherlands, where it was a massive parking lot and they had infiltration and that it was damaging the whole structure because of cracks. So what they decide to do is to spray this self healing technology using bacteria over the whole structure, and it would repair itself and hopefully it could repair in the future autonomously as well.

Chris - Yeah could be bad if you've got a really ugly housing estate though that you'd quite like to fall down and you're coming along with your self healing concrete could mean it's a monstrosity for a lot longer than we’d like couldn’t it?

Lívia - That would be bad!