Rachel Armstrong: Architecture that repairs itself?

All buildings today have something in common.

They're made using Victorian technologies.

This involves blueprints,

industrial manufacturing

and construction using teams of workers.

All of this effort results in an inert object.

And that means that there is a one-way transfer of energy

from our environment into our homes and cities.

This is not sustainable.

I believe that the only way that it is possible for us

to construct genuinely sustainable homes and cities

is by connecting them to nature,

not insulating them from it.

Now, in order to do this, we need the right kind of language.

Living systems are in constant conversation

with the natural world,

through sets of chemical reactions called metabolism.

And this is the conversion of one group of substances

into another, either through

the production or the absorption of energy.

And this is the way in which living materials

make the most of their local resources

in a sustainable way.

So, I'm interested in the use of

metabolic materials for the practice of architecture.

But they don't exist. So I'm having to make them.

I'm working with architect Neil Spiller

at the Bartlett School of Architecture,

and we're collaborating with international scientists

in order to generate these new materials

from a bottom up approach.

That means we're generating them from scratch.

One of our collaborators is chemist Martin Hanczyc,

and he's really interested in the transition from

inert to living matter.

Now, that's exactly the kind of process that I'm interested in,

when we're thinking about sustainable materials.

So, Martin, he works with a system called the protocell.

Now all this is -- and it's magic --

is a little fatty bag. And it's got a chemical battery in it.

And it has no DNA.

This little bag is able to conduct itself

in a way that can only be described as living.

It is able to move around its environment.

It can follow chemical gradients.

It can undergo complex reactions,

some of which are happily architectural.

So here we are. These are protocells,

patterning their environment.

We don't know how they do that yet.

Here, this is a protocell, and it's vigorously shedding this skin.

Now, this looks like a chemical kind of birth.

This is a violent process.

Here, we've got a protocell to extract carbon dioxide

out of the atmosphere

and turn it into carbonate.

And that's the shell around that globular fat.

They are quite brittle. So you've only got a part of one there.

So what we're trying to do is, we're trying to push these technologies

towards creating bottom-up construction approaches

for architecture,

which contrast the current, Victorian, top-down methods

which impose structure upon matter.

That can't be energetically sensible.

So, bottom-up materials

actually exist today.

They've been in use, in architecture, since ancient times.

If you walk around the city of Oxford, where we are today,

and have a look at the brickwork,

which I've enjoyed doing in the last couple of days,

you'll actually see that a lot of it is made of limestone.

And if you look even closer,

you'll see, in that limestone, there are little shells

and little skeletons that are piled upon each other.

And then they are fossilized over millions of years.

Now a block of limestone, in itself,

isn't particularly that interesting.

It looks beautiful.

But imagine what the properties of this limestone block might be

if the surfaces were actually

in conversation with the atmosphere.

Maybe they could extract carbon dioxide.

Would it give this block of limestone new properties?

Well, most likely it would. It might be able to grow.

It might be able to self-repair, and even respond

to dramatic changes

in the immediate environment.

So, architects are never happy

with just one block of an interesting material.

They think big. Okay?

So when we think about scaling up metabolic materials,

we can start thinking about ecological interventions

like repair of atolls,

or reclamation of parts of a city

that are damaged by water.

So, one of these examples

would of course be the historic city of Venice.

Now, Venice, as you know, has a tempestuous relationship with the sea,

and is built upon wooden piles.

So we've devised a way by which it may be possible

for the protocell technology that we're working with

to sustainably reclaim Venice.

And architect Christian Kerrigan

has come up with a series of designs that show us

how it may be possible to actually grow a limestone reef

underneath the city.

So, here is the technology we have today.

This is our protocell technology,

effectively making a shell, like its limestone forefathers,

and depositing it in a very complex environment,

against natural materials.

We're looking at crystal lattices to see the bonding process in this.

Now, this is the very interesting part.

We don't just want limestone dumped everywhere in all the pretty canals.

What we need it to do is to be

creatively crafted around the wooden piles.

So, you can see from these diagrams that the protocell is actually

moving away from the light,

toward the dark foundations.

We've observed this in the laboratory.

The protocells can actually move away from the light.

They can actually also move towards the light. You have to just choose your species.

So that these don't just exist as one entity,

we kind of chemically engineer them.

And so here the protocells are depositing their limestone

very specifically, around the foundations of Venice,

effectively petrifying it.

Now, this isn't going to happen tomorrow. It's going to take a while.

It's going to take years of tuning and monitoring this technology

in order for us to become ready

to test it out in a case-by-case basis

on the most damaged and stressed buildings within the city of Venice.

But gradually, as the buildings are repaired,

we will see the accretion of a limestone reef beneath the city.

An accretion itself is a huge sink of carbon dioxide.

Also it will attract the local marine ecology,

who will find their own ecological niches within this architecture.

So, this is really interesting. Now we have an architecture

that connects a city to the natural world

in a very direct and immediate way.

But perhaps the most exciting thing about it

is that the driver of this technology is available everywhere.

This is terrestrial chemistry. We've all got it,

which means that this technology is just as appropriate

for developing countries as it is

for First World countries.

So, in summary, I'm generating metabolic materials

as a counterpoise to Victorian technologies,

and building architectures from a bottom-up approach.

Secondly, these metabolic materials

have some of the properties of living systems,

which means they can perform in similar ways.

They can expect to have a lot of forms and functions

within the practice of architecture.

And finally, an observer in the future

marveling at a beautiful structure in the environment

may find it almost impossible to tell

whether this structure

has been created by a natural process

or an artificial one.

Thank you.

(Applause)