JENNY SABIN: And it's my pleasure to introduce Richard Bonser, who is a Reader in Design at the School of Engineering and Design at Brunel University in Uxbridge, UK. His post-doctoral research at Bristol, Manchester, and Oxford Universities focused on the locomotoring biomechanics of animals and root anchorage in tropical trees. In 1998, he became senior researcher scientist-- or senior research scientist in biomaterials at Silsoe Research Institute, moving on to pursue a lectureship in biomimetics at the University of Reading in 2002.
His current research focuses on developing novel and sustainable technologies, frequently involving inspiration from natural systems. He has successfully led research projects for numerous customers, including the European Space Agency, UK Sport, the European Union, and industry and has published much of his work in leading international journals. As part of an 8 billion euro EU consortium grant, Bonser is currently working to develop a soft-bodied, octopus-inspired robot. Bonser graduated from the University of Sheffield with a BS in zoology in 1990 and completed his PhD in the mechanics of biological materials at the University of Bristol in '93.
Please help me in welcoming Richard Bonser.
RICHARD BONSER: Thank you Jenny and good afternoon ladies and gentlemen. And thanks to the organizers for inviting me to speak here today.
Now, my talk today is going to be composed of really two parts. The first bit is about what biology can do for buildings. And the second bit is what buildings can do for biology.
Now, the first bit that I'm going to talk about is biomimetics. And this is all about gaining inspiration from nature for new technologies. So the first question I'm going to answer is why on Earth should we be bothered doing this and what's the potential advantage of this approach? Then I'll look at some applications of biomimetics that have been applied to buildings. And then, finally, I'll look at the second half of the story, which is trying to understand what buildings can possibly do for biology.
Now, the idea of imitating structures from nature isn't particularly new, although its only been in the past 30 or so years that we've seen a lot of academic and research activity involved in doing this. And if we go back to the 16th century and the notebooks of Leonardo da Vinci, we can see that Leonardo himself was very inspired by nature. And what he was basically saying here was that although humans could be very clever in developing new structures or inventions, they never did it in quite the economic and simplified way that it occurs in nature.
So really, one potential output of biomimetics is getting simplified economic structures that have a high degree of functionality. Now, we don't think about it a lot. But organisms occupy a very physical environment. So we can have gravity acting on us, which we do when we're walking around. It mediates the growth of trees, the direction that they grow on sloping grounds.
We can have fluid flows. And these may be internal or external. So at the moment, we're pumping around eight pints of blood around our body. We're also breathing, taking in oxygen from the environment. So there's a lot of fluid mechanics going on there.
Surface tension and wetting can be very important. If you're a very small organism, it's very easy to become trapped in a fluid film and subsequently die. But some organisms can manipulate surface tension to do clever things. Insects like pond skaters rest on little dimples in the water and can skate across the surface of water bodies.
We can also have frictional interactions. Our joints depend on having relatively friction-free surfaces. If our lubrication system breaks down, movement can become very painful and difficult.
Also lots of organisms occupy environments under the surface of the soil. So we can have animals that burrow through the soil. And also soil acts to impede the growth of plant roots.
There are also some amazing aspects of adhesion in biology. Anybody who's been to the tropics may have been lucky enough to see a fantastic animal, the gecko, that can run up vertical walls due to some really neat adhesive structures that it has in its feet.
We can also have adaptations to cope with impact. Again, think about nature documentaries. We often see footage of mountain goats crashing headlong into each other. But, usually, they both walk away relatively unscathed. So there's a lot of design there to prevent damage to the animal.
Also, think about the wider physical environment. Temperature can be very important. Both for warm-blooded animals, like us, retaining body heat when it's cold, and for cold-blooded animals, gaining heat from the environment in order to increase their metabolic rate.
And finally, gas transfer, which again is a process that we're doing at the moment. We're expelling carbon dioxide from our lungs and taking in oxygen. Plants, of course, do the reverse, taking in CO2 from the environment and expelling oxygen.
So I hope you can see that there are lots and lots of physical ways that organisms interact with their environment. So I hope it's not too much of a leap of faith to see that there are adaptations in organisms that address the very physical questions that we see in engineering, architecture, and construction.
It's also very handy that the size scales of life roughly correspond with the size scales of technology. So at the moment, we're not really working much at the nanometer scale, apart from nanotechnology. But we've got a whole range of organisms that pretty much cover the size range that we find in technologies. Now, this is quite handy because scale often affects physical interactions. So we can see there's a commonality of scale that enables us to really easily crossover mechanisms from biology to technology.
Another thing that's interesting to consider is the way that different factors are used in solving problems in engineering and biology. And this brightly colored graph came out of some work carried out by Julian Vincent and his colleagues at the University of Bath in the UK. And they were interested to examine the different ways in which biology and technology solved problems.
So along the horizontal axis, we've got scale, from nanometers up to kilometers. And on the vertical scale, we've got the proportion of problems that have been solved due to one of these six factors on the right. Now, as the meeting today is about sustainability, I'd particularly like to take note of the very large red block on the graph. And this represents problems that have been solved by manipulating energy.
So in engineering and technology, we have a very high proportion of problems that are solved by manipulating energy. When we look at the corresponding graph for biology, we find that the red bar almost disappears. So nature doesn't seem to utilize energy as a major way of solving problems.
Now, there are very good biological reasons why this is the case. We're all here to send off copies of our genes into the future. So if you're wasting energy unnecessarily, you've got less energy available to invest in doing that. So you could almost think that copying or taking inspiration from biology might mean that we can save energy. And that can be no bad thing for sustainability.
So I think to summarize those graphs, what the message I'd like to leave you with is that nature tends to manipulate energy less than does technology. And this means that taking a biomimetic approach to innovation may mean that the outputs could be more sustainable.
Also, biology is very good at using relatively few materials. Basically, there are five classes of materials found in biology. If you look around a building like this, I guess you'll get into tens, if not hundreds, of different sorts of materials. So again, nature is a bit smarter in the way it uses materials and also how it structures them.
Also, nature's very good at manufacturing things with very low energy inputs. If we want to make ceramics, it involves heating to thousands of degrees, lots of chemistry and resource input. If nature wants to do it, it can do it in salt water, at 5 degrees centigrade, from precursors such as algae.
Again, closer to home, if we look at spider silk, it's this marvelous material that has properties perhaps only rivaled by things like Kevlar. Again, your spider in your house can be a happy manufacturing factory, which is using precursors that are no more noxious than the flies it catches. Yet, it can produce a fantastic material at the end. So I'd like to propose that there's really quite a lot we can learn from biology that can make technology a lot cleaner and greener.
So really we've got a massive resource to build on. There's conservatively been estimated to have been life on Earth for at least 2 billion years. So there's been a lot of trial and error for solving problems.
Secondly, I think taking a biomimetic approach can lead to cleaner, greener solutions to problems potentially. Also, it can lead to added functionality. It's very rare in nature to find a structure or material that only does one thing. It can provide us with new routes to problem solving. And hopefully, the crunch issue is it can add value to industrial process by increasing profitability or reducing cost.
Now, to illustrate the process of biomimetics, I'd like to show you what we can consider to be the grandfather of biomimetic innovations. And it's the fastener we all know as Velcro. Now, Velcro was developed by a Swiss postal engineer, George de Mestral, in 1948. And he happened to take his dog for a walk through the woods. And when he got home, his dog had lots of burdock seed burrs, which are pictured on the left, attached to his dog's coat.
Now, de Mestral's genius was to recognize the underlying mechanism and reasons for it. Now, the burdock seed is effectively hitching a ride on a passing animal. So it needs to attach to the animal's fur quite firmly so it gets carried away, but not so firmly that it never drops to the ground and germinates.
So de Mestral recognized that this would be a good way of joining textiles as an alternative to zippers, or hooks, and eyes. He also recognized the basic physical mechanism of this interaction. So rather than slavishly copying the structure of his dog's fur and slavishly copying the burdock seed, he looked for the basis of the mechanism, which was the interaction of a rigid hook with a flexible loop.
And this is how we also get the name for Velcro. Because we've got velour from the French, meaning "fabric," and crochet, meaning "hook." Well, as they say, the rest is history. And from de Mestral's genius, an industry came about that produces profits of around $200 million a year.
So moving closer to all of your interests, what I'd like to do is briefly go through some recent biomimetic innovations that are contributing to the built environment, and potentially for sustainability. And I'll look very briefly at architecture because you probably know more about bioinspired and biomimetic architecture than I do. But then I'll look a bit at building components, and also building services, and how biomimetics can influence these.
Well, there are lots of bioinspired buildings out there. Some of them, I would argue, are what could be considered to be either zoomorphic or biomorphic. So it's really imitating the form, rather than the functionality of the biological system. But, of course, there are exceptions.
This is Mike Pearce's Eastgate Centre in Harare, in Zimbabwe. And the natural ventilation of this is supposedly inspired by airflows through termite mounts. So there are quite a lot of examples there of buildings which have been constructed, that either contain directly biomimetic components or, alternatively, by biomorphic aspects.
Thinking more about construction materials and products themselves and how biomimetics can improve sustainability, I'd like to tell you the Lotusan story. Now, some scientists at the University of Bonn in Germany started to investigate the remarkable self-cleaning properties of the leaves of the sacred lotus. And these are pictured on the right.
Every time it rains, water falls on the leaves of these plants. It forms tiny droplets and rolls off. But any dirt on the surface of the leaf gets simply carried away with the water droplets.
Now, one of the key things that they were interested in was understanding the phenomena of why the leaf didn't get covered in a surface film of water? Why did water form very discrete droplets? Well, they did some research.
They found out the physical mechanism that caused this. They published a few papers. And then pretty much forgot about it. But it's now a commercial success. And this is mainly perhaps because a German company called Sto recognized the potential of this mechanism for surface protection.
Now, the way in which the lotus effect works is really quite simple. The surface of the lotus leaf is incredibly rough at the micron scale. So it's covered in tiny bumps composed of waxes from the cuticle of the outer skin of the leaf.
Now, these tiny bumps create an effect known as superhydrophobicity. So the contact angle of the water becomes very high. So water droplets are effectively spherical and don't form films across the surface of the leaf.
Now, the second part of the effect is that dirt particles have very little contact area because the surface is so rough. So when the water droplet rolls over the surface of the leaf, the dirt particles have more affinity to the water droplet than they do to the surface. So they get attracted to the water droplet. And the water droplet simply rolls off, taking the dirt with it.
Now, as I mentioned, German manufacturer Sto spotted the commercial possibility for this and managed to produce a paint that works in a very similar way. So this is an external masonry paint. The image on the bottom-right comes from their publicity material. Obviously, the building on the left has the lotus effect. And that's why it's nice and bright and white. And the one on the right, doesn't.
The paint generally costs about twice that of traditional masonry paint. But it seems to have a service life that's twice as long. Also, if you want to clean your paintwork, you just require to spray it with water, rather than use any form of detergent.
Now, the effect isn't just useful for masonry paints. It's being applied to a whole different variety of other materials. There are toilet fittings that have been developed which decrease microbial contamination; roof tiles made from polymers, which prevent algae and moss spores from gaining a foothold and growing; and also for textiles.
Thinking about sustainability, we're always drawn back to how we actually manufacture energy. And biomimetics is also having an influence on energy generation. This innovation here comes from Japan. And here you get two bits of biomimetics for the price of one.
This microwind turbine for use on small buildings is known as an airdolphin. And the first bit of biomimetics came about through the desire to reduce the noise production by the rotating rotors. And the engineers involved in developing this looked to owls to find their solution.
Now, owls are remarkable for the fact they are very quiet, if not silent, during flight. The reason for this is that flapping noises from their wings might alert their potential prey to their presence and enable them to escape. And the owl does this apparently by having very fine fringes along the leading and trailing edges of its feathers. And these seem to decrease the amount of noise that's generated as the bird flaps its wings. So the engineers implemented a very similar system of ridges towards the leading and trailing edges of the rotors. And this, indeed, seemed to decrease the amount of noise produced.
Secondly, traditional microturbines have a rigid tail vane. And one effect of this in gusty or changeable winds is that the turbine tends to flip in and out of the direction of airflow. So for a lot of the time, it isn't producing any energy. By having a flexible tail, obviously supposedly mimicking a dolphin, this tends to damp out a lot of this twitchiness in motion. So the rotor spends more time aligned in the direction of airflow.
We've also got an innovation that's inspired by bumps on the fins of whales that are known as tubercles. This work was initiated by Frank Fish from West Chester University here in the US. And he really wanted to understand why whales had these old lumps on the leading edges of their fins.
Well, in collaboration with some other workers, they identified that it did have an aerodynamic effect in that it increased the speed at which aerodynamic stall-- or it decreased the speed at which aerodynamic stall would occur. So this means vanes of the turbine can have a steeper angle. So they can generate more power, even at lower speeds.
Biomimetics is also providing new technologies that may have uses in intelligent buildings. And this is a project at which I was part of the University of Reading. And this was all about learning about sensors that you find on crickets.
Now, crickets have two organs, here and here, which are called cersei. And they are covered with literally thousands of different types of sensors. So these paddle sensors here are thought to detect gravity. So the insect knows which way up it is. And we've got some long fibers here, which detect airflows. And there's also some little pick-lick sensors here which detect different chemicals.
So why should a cricket require this huge array of sensors? Well, the airflow sensors almost act like it's radar. It uses them to detect the approach of predators, such as hunting spiders. Now, the cricket needs to be able to jump away from the approach of a predator, but not spend its entire existence jumping away from imaginary predators, that may simply be gusts of wind. So it needs to do quite a bit of discrimination.
Now, it proved possible to manufacture MEMS devices, microelectrode mechanical systems, which mimicked the action of the hair. So in a 5 by 5 millimeter MEMS device, you could have a hundred or more tiny hair sensors.
Well, there are two great things about this. Potentially, they can discriminate between the movement of a person into a room and airflows that may be due to a window being left open. Also, because you've got a high number of sensors, there's a high degree of redundancy. So if one fails, you've still got 99 that can do the job. And also, it has a degree of directionality. So you can work out exactly where your person has entered the building or where the window has been left open.
There are also applications in robotics that have a great potential for the built environment. And these two slides, this and the next slide, relate to the OCTOPUS project. Here, we're aiming to develop a soft-bodied, octopus-inspired robot.
Why an octopus, you may ask? Well, an octopus has a number, eight, of arms or legs. And it can move these with an almost infinite degrees of freedom. So it can use them to do tasks such as walking around, swimming, and also, more importantly, grasping and manipulating objects. Now, the real octopus can almost double the lengths of its arms to reach out and grasp objects, then pull them back towards it, and manipulate them.
So it has a great potential for applications, for example including underwater maintenance. I mean, we always joke that BP would have perhaps loved one of these in the Gulf of Mexico a few years ago because the robotic entity could have taken a eight spanners under the sea and used them. But anyway, we're a bit late for that.
So my colleague Dr. Jinping Hou is the research fellow on in this project at Reading. Now, Reading's role in the project was developing a sensorized, tough, waterproof skin. And along the way, we decided it might be useful to provide some structures that would enable the robot to grasp things. So we had to look at suckers as well.
So bottom-right, you can see-- oops, bottom-left, sorry, you can see a real sucker from a squid. We decided to look at squid suckers because they appear to work almost passively. An octopus sucker is a very muscular organ. And to be honest, it's hard enough to make a robotic octopus arm extend, let alone have lots more actuators to enable it to grasp objects.
So we successfully managed to copy the squid sucker. And that's pictured top-left. So this is a very simple system that can generate newtons of, force with pretty much an entirely passive mechanism.
We managed to manufacture a tough waterproof skin. And you can see this with the suckers attached on the top-right, together with flexible textile-based sensors underneath that enable contact with surfaces to be detected.
So what can biology do for buildings? Well, I think it can provide marvelous inspiration for architects, both in terms of form and functionality of buildings. There are ways in which I think natural systems can help us reduce energy demand. Also add intelligence, make things a bit cleverer. And finally, and importantly, increase efficiency.
Well, for the last five or so minutes I'm going to talk a bit about what buildings can do for biology. Well, as we've already heard today, there are lots of interactions of animals with the built environment. And, indeed, many man-made structures have become homes for animals. Of course, we spend a lot of our time trying to stop them being homes for animals.
We get a wide variety of animals using buildings, both vertebrate and invertebrate animals. And again, as we mentioned earlier, some of these we tend to regard as pests. So we don't want them anywhere near our buildings. But some can be beneficial.
And importantly, some are endangered. So may have legal protection. So it's simply a case that you can't disturb or remove them.
There are also issues in that often animals have been forced to use buildings because their natural habitats have been reduced. And one group of animals that I'm going to talk about in a minute, bats, actually do this. Normally, many species of bats would roost in trees. But with deforestation, they have no option but to adopt the roofs of buildings as an alternative home.
Now, research into making buildings more animal friendly, I think it's something that's rather urgently required. There's been considerable research into the interactions of farmed animals with the built environment. These have been due to concerns of productivity and also welfare. And they've not been constrained simply to looking at the mechanics of the building, but also the remainder of the physical environment.
So around us, we've got some fluorescent lights here, which appear to us to be constantly shining. However, if you're a chicken, they are flickering quite alarmingly. So the flicker fusion of a chicken or pigeon is around 100 Hertz. For us, it's around 50 Hertz. So it would appear that this room was full of flashing lights. It would been really quite unpleasant.
But we know less, far less, about the preferences of wild animals for different parts of buildings. Now, there are several factors that can affect how animals may or may not use buildings. We can have temperature effects. Certain animals prefer to roost or reproduce at different temperatures.
We can have humidity. We can have textures. It's easy for the animal to grasp hold of the surface. And this can be linked to mechanical properties.
We can have the presence of light, as in chickens. And also providing adequate access to a building, to enable an animal to utilize it. So really this means that we need to do more research into understanding the mechanical and physical requirements of animals in relation to their use of buildings.
So mechanics of substrates can both positively and negatively affect animal habitation. So really, can we come up with solutions that enable certain species of animals to use buildings better?
Now, my research student Stacy Waring is looking at this problem in collaboration with the Bat Conservation Trust. And here, we've got a remarkable conflict. There's been a move in recent years to replace bitumen-based textiles underneath roofing tiles with spun-bonded polymers.
And we can see, on the top-right here, lots of bats roosting on polymer membranes. Now, these membranes are supposed to be good for the building because they allow moisture to escape, decreasing the risk of perhaps rot in roofing timbers. But there is an issue with entanglement.
Bats' tiny claws can become entangled in these fine fibers. And they're unable to escape. So Stacey's project is really starting to understand which are the factors of particular membranes that make them more or less bat friendly.
Just to illustrate some of the work we've been doing-- this was the work of an intern, Alice Lightowlers. And she was investigating the frictional interactions of bat fur with breathable roofing membranes. Because many bats live underneath the tiles. So the underside of their body comes into contact with the membrane.
Obviously, we couldn't use real bats because they're protected. So this is Alice's artificial bat, which has a similar contact pressure to a real bat. And the fur is derived from a mole, which is an unprotected pest species in the UK.
So she found out that bitumastic felt had a very high coefficient of friction. Breathable roofing membranes were much more variable. And that there was little effect of the pile, i.e., the way the fibers lay on the bat's body, on its frictional interactions with the environment.
So to summarize, with biology using buildings, we have a relatively poor understanding of animals' requirements for using habitation. Also, I think we need to make sensible decisions at the design stage, how we may want to incorporate measures within buildings that can make them more wildlife friendly, providing refuges. And perhaps really the thing to think about in the future is having the whole menagerie of having your own little wildlife reserve present within the walls and rooms of your building.
And this, in a way, that can be beneficial. Certainly in this part of the US, there's been an outbreak of white-nose disease in bats. And this means that some 2.8 million pounds of insects are not going to be eaten in the Northeast of the US this year. So that means potentially increased use of pesticides.
Anyway, to conclude, I think learning from biology can help us make buildings more sustainable. And conversely, we need to learn more from biology to make buildings better homes for them. So I'd like to thank you for your attention.
JENNY SABIN: We have time for a couple of questions. Are there are questions from the audience?
SPEAKER: Hello. I don't have a specific question. But I was really fascinated by the kind of soft-rubbered idea, which has been developed in relation to the octopus model.
And I was thinking this idea of the infinite degrees of freedom that the octopus has in its tentacles, I was trying to understand how does he figure out how to control them? Because like when we do little experiments with sensors, actuators, obviously the difficult part is always to program them. And when the numbers increases, it becomes more and more difficult. And I was trying to decide how come the octopus doesn't have an enormous brain? How can he actually compute the whole thing?
RICHARD BONSER: An octopus does have a pretty huge brain. It's widely regarded as being the cleverest invertebrate. And certainly in the UK context, they are treated for, in terms of animal experimentation, as honorary vertebrates.
They're very clever. They have a high degree of visual acuity. And also they have a lot of sensors within their skin, so chemical sensors, touch sensors, et cetera. So they've got a lot of computing power and a lot of sensing too.
RICHARD BONSER: It's pretty much all in their brain.
JENNY SABIN: Other questions? OK, thank you Richard.
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Richard Bonser of the School of Engineering and Design at Brunel University gives a presentation at the 2012 Hans and Roger Strauch Symposium on Sustainable Design, "Sustaining Sustainability: Alternative Approaches in Urban Ecology and Architecture," February 4, 2012.
The symposium was organized jointly by the Cornell University Department of Architecture and the Oslo School of Architecture and Design Research Center for Architecture and Tectonics.