The search for sustainable materials

What else does the future hold for materials science? Well with a rising world population placing increasing pressure on our resources, a major priority is to produce materials sustainably and also make the most efficient use that we can of what we already have. Now this is called a circular economy, and it's a concept that Alysia Garmulewicz has been looking at in some detail. She is from the University of Santiago in Chile and is Director at Materiom, an open knowledge platform for making materials from locally abundant bio-based ingredients.

But what actually is a circular economy as applies to materials? Alysia joined Chris Smith in the studio to give some examples.

Alysia - It’s usually thought of in terms of two major cycles. One is the biological cycle, so on the one hand we’re looking at materials that can actually enter back into the biosphere and be returned and actually regenerated on the basis of natural systems. And then another cycle is technical materials, so those materials that don't very well go back into the biosphere but we need to then engineer ways to return those back into useful purposes for our human industries. So in terms of the material cycles it’s usually broken up into those two sections.

Chris - So at the moment, for example, I get some oil out of the ground, I turn it into a plastic bag. This is a very bad example of a circular economy because it's a one-way street. I've made the bag, is gonna sit there in landfill for potentially thousands of years?

Alysia - Precisely. Yes, so that's a good example of the linear economy that we have now and the problems underpinning it.

Chris - So you're advocating some kind of rational design of something - a better bag if you like - that means that we start with a different starting material or we engineer in some kind of recyclability from the get-go?

Alysia - Exactly. We need to think about regeneration as the kind of guiding principle and one of the major things that my work focuses on is reimagining where that takes place, the scope and scale. So one of the things that is currently in the discourse of the circular economy is the idea of cycling, that's kind of implicit in the concept. But what is a kind of next-generation, I think, of work in this area is looking at what appropriate scale can we make the materials and return them back. So if you look at natural ecosystems, you look at how materials, actual molecules get absorbed into the organisms that then build habitat etc. but that's usually at nested, quite local and regional scales in terms of the cycling.

What we do now is we dig up minerals from mines or petrochemicals from large, large deposits and then create huge, global supply chains in order to actually transport those materials around the world. The problem is that you then have centralised material production and distributed waste. And when you think about that as an issue of trying to pipe that back into all that distributed bits of waste back into a centralised production system it's incredibly uneconomic and very difficult. So one of the ideas is decentralising that type of material supply chain into more nested nutrient networks.

Chris - That's true of economies and industries all over the world, isn't it? Because I was shocked a few years ago when I learned that the prawns I cooked for dinner one evening had been caught on one side of the Atlantic, shipped all the way to Thailand, shelled on the ship, cooked out there and brought back for me to eat. So those prawns had travelled further in their lifetime than I have probably, around the planet, and you think the carbon cost of that. But it's not trivial then is it because the whole world economy is geared up around making stuff at scale and then moving round to an end-user. So what you're advocating is a massive, massive overhaul of how we make stuff and use stuff?

Alysia - Precisely. And I think it's a really good analogy to look at food systems that there's really good logic for more regional local supplies for reasons and also energy. So the kind of renewable revolution that's happening right now is it's starting from the premise of what is around you, what makes sense to be adaptive in this place that we live in. And the next step that is materials, and you point out quite rightly that it's a huge revolution in the way things are done. However, there are seeds of change that are out there right now; for example in the digital fabrication space where fab-labs and makerspaces and local communities of production are popping up everywhere. That gives hope for a more decentralised or distributed manufacturing landscape that currently is in the wings, so to speak, but could be a harbinger for a greater future transformation in that sense.

Chris - But I get what you're saying. The thing is that if you look at say computers, mobile devices, they’re all mass-manufactured in China and they're travelling enormous distances. Some of the materials travel enormous distances but they’re also being made where those materials are in abundance. Now we’re not just going to wean the entire world off overnight of having a laptop and an iPhone are we? So there are going to be some things that presumably are not amenable to doing this - there are going to have to be exceptions?

Alysia - I think that's true and I think you have to look at the kind of volume of materials that we want to focus on in terms of making that change to begin with. We focus a lot on plastics, we focus a lot on materials that can be sourced from abundant sources of nutrients from biomass so, for example, lignocellulosic materials that are the building blocks for trees and all plant matter basically, that’s highly distributed and abundant all over the world. As well as, for example, we’re doing a lot of work on making algae-based bioplastics. Agar is a biopolymer that you could make from algae but that is actually common to a phylum called red algae, which contains about over four thousand species that is highly distributed around the world. So the idea that you could actually make and fabricate functional plastics pretty much anywhere on the planet is the vision that we see as completely possible.

The other aspect is that when you combine that with technology that’s highly participatory in terms of using green chemistry methods - that's low heat and low pressure - basically the plastics we're making you can make in your kitchen or at least in a small lab. That's the kind of technology that allows more people in more places to participate in this new materials economy.

Chris - It just seems amazing that we spent all of our history scaling things up and working out how to make bigger things and get them to places faster, and now we’re bringing it all back to home and making it local again, making it artisan almost. It's extraordinary!

Alysia - I think that an interesting trend. I think that on the one hand you have things that will be large in scale and then other things that will be small-scale, and it's more the question of what's the appropriate scale for the type of material and the type of production that we want.