Self-healing at the Serpentine
Was fortunate to attend another excellent Arup Penguin Pool event last night. The themed events, which take place at Arup locations worldwide, are orchestrated to promote cross-disciplinary conversations and seed future collaborations. They are also for fun, though. The venue this time was Herzog & de Meuron and Ai Weiwei’s 2012 Serpentine Pavilion (Arup has engineered every Pavilion since the first in 2000). The theme: ‘self-healing materials’.
What on earth are self-healing materials?
In the spongey cork dell of the pavilion, materials scientist Mark Miodownik, Professor of Materials and Society at UCL and director of the Institute of Making, explained that there is a lot to be learnt from the the basic building block of the natural world – the single cell. Cork, for example, is a natural, cellular material that is self-generating in as far as the cork tree keeps growing the stuff after a layer is harvested. Miodownik described how understanding of natural cellular structures with their self-healing, self-organising capacities is being transferred to investigations into materials – even structures – with inherent healing capacities.
And not all of this is as far off as one might think: self-healing concrete, for instance, is almost a reality. By incorporating a specific bacteria into the mix as well as starch for it to feed on, the concrete is able to self-heal as the bacteria migrate towards fissures and excrete calcites to, in effect, bridge the gaps. This technology is at full-scale prototype testing stage. It’s looking as if damaged material can regain 90% of its original strength.
Another approach to self-healing concrete that is being researched involves the inclusion a form of liquid resin that remains dormant within capsules until stress or shock cause the capsules to break open and perform like a clotting agent in a one-off healing action. Or what about a hybrid approach where engineers create ‘scaffolds’ for structures that are seeded with organisms so that they gradually build themselves?
‘But hold on’, says Stuart Smith of Arup, ‘We get two months to design the engineering of a pavilion and six weeks for the build. Can this be made to work with our real, human, timescales?’
‘Bamboo?’ responds Miodownik, undaunted, ‘It grows like the clappers.’