Dr Alex Parfitt, a biologist-turned-engineer at BAE Systems, explains the impact of biomimetics on the development of innovations in defence technology. Jon Excell reports.
Self-repairing materials, tiny aerial spies, advanced image sensors and armies of swarming drones effortlessly constructing buildings of incredible complexity.
A leaked list of top-secret military projects? Or Hollywood’s latest imagining of a dystopian near-future?
Actually, it’s neither. But if you look closely enough, it is the kind of scene you might find at the end of your garden, as ants, bees, birds and other assorted denizens of the undergrowth quietly scurry about their business.
A growing realisation that the hi-tech wish lists of the modern age frequently have ready-made solutions in the natural world is driving the commercial emergence of biomimetics: the science of borrowing functions and mechanisms from the natural world to solve engineering problems.
Perhaps unsurprisingly, it is in the defence industry, where demand for new technology is high and with budgets to match, that the biomimetic approach is having the biggest impact.
At the cutting edge of the UK’s contribution to this most intriguing area of engineering is BAE Systemsbiologist-turned-engineer, Dr Alex Parfitt.
Based at BAE’s advanced technology centre in Filton near Bristol, Parfitt, whose biological insight stretches from the mechanical properties of wood to the unusual aerodynamics of feathered flight, has become a valuable resource. ‘There are around 14 different disciplines, which all tie-in to biology,’ he said. ‘I get to see a huge number of issues that come through the company.’
It’s a far cry from his former role in academia, and Parfitt talks with evident delight about the resources now available to him. ‘If we are working on porous wings, I’ve got a team of CFD modellers that I can call on immediately. If we are doing some micro-electronics work, we’ve got a clean-room facility in the basement of the building so I can go to the MEMs department and get something fabricated at the same sort of scale as biology. We’ve got a human factors department, an optics and laser department. Depending on what the project is, you can draw on those disciplines. It’s a nice little place to be sat – a little bit like academia, but I like to think I have got people around me who are more focused on designing an end product.’
Parfitt is clearly smitten with the field. ‘I can remember when I first heard about it in a lecture and thinking, “someone could make some money out of that”.’
And while most of his contemporaries studied more conventional aspects of the biological sciences, Parfitt ploughed a rather different furrow, first badgering the Ministry of Defence to let him use its submarine test centre to study penguin hydro-dynamics, and later, for his PhD at Bath, looking at the development of colour-changing materials inspired by the adaptive colouring of cuttlefish.
‘After I finished these projects I thought, “it was good fun, but who on Earth is going to employ this sort of biologist-engineer?”’ recalled Parfitt. Fortunately for him, his academic speciality coincided with a growing interest from industry, and right on cue BAE Systems placed an advertisement for a biologist. Parfitt got the job.
Since then, a steady stream of biologically inspired ideas have emerged from Parfitt’s lab.
One of the first was a super-adhesive material that replicates the gravity-defying properties of a Gecko’s foot (The Engineer, August 2006). This material, one square metre of which is reportedly strong enough to hoist a family car into the air, is the subject of an ongoing project at BAE.
From Geckos to shellfish, no stone is left unturned in the search for promising new materials and Parfitt’s wish list of research projects is long. ‘Mother of pearl, keratins, hoof, nail, beak, silks and bone tusk are all things with very high mechanical properties. They have all been discussed in biomimetics for a while but I think from a defence point of view there’s a lot that they could offer as novel new materials.’
And while biomimetics is typically associated with the animal kingdom, the plant world can also teach us some important lessons. For instance, Parfitt is particularly keen to build on earlier research looking at the development of materials that mimic the high strength and low-density properties of wood. Lightheartedly stressing that BAE is not funding research into the development of wooden tanks, he explained that wood does nevertheless have some very attractive properties. ‘Wood has a higher work of fracture [a measurement of a material’s resistance to failure],’ he said. ‘For its density, it is comparable to steel and a lot better than fibreglass.’
Back in the animal kingdom, feathered flight is the subject of an ongoing research project. ‘A bird’s wing is a highly porous structure,’ explained Parfitt. ‘You can blow through a feather and feathers are layered upon each other. Plus, there are more feathers towards a leading edge and less toward the trailing edge. We want to understand the advantage of that layering structure.’
Although he was unable to comment further on the status of this project, Parfitt confirmed that his group has successfully identified the aerodynamic advantages of feathered flight.
As well as replicating and mimicking structures of the natural world, Parfitt’s group is also investigating animal behaviour, and in particular the behaviour of swarming insects.
Study of this form of highly complex distributed intelligence is feeding directly into the development of the advanced processing required to enable autonomous robots to work alongside each other. ‘We are interested in how a swarm works so we can then think about larger groups of platforms, such as UAVs or ground platforms,’ said Parfitt.
This work is part of a wider project called MAST (Micro Autonomous Systems and Technology) in which BAE is working alongside a number of US universities and research laboratories on the development of tiny, insect-like robots that could be used for intelligence gathering.
The insect world, frequently the inspiration for biomimetic projects, is also leading to some exciting advances in vision systems. Indeed, one of the projects about which Parfitt is most excited is the development of an advanced panoramic vision system inspired by the compound eye of a tiny parasitic insect that lives inside wasps’ abdomens. (The Engineer, 29 September 2008). The device, capable of 120° field of vision, could be at the heart of vision systems such as missile-tracking systems, but could also be integrated into night-vision equipment for troops. Of all his current projects, BugEye, said Parfitt, is perhaps the closest to commercialisation.
There’s no doubt that biomimetics sits at the most esoteric end of the engineering spectrum. But there are also strong signs that it’s being taken increasingly seriously.
While five years ago the field was the preserve of a handful of forward-thinking individuals from the world of biological sciences, Parfitt detects a huge growth of interest in the field. ‘There are so many people now who are interested in this. Not just biologists, but chemists, textiles people, architects and even business managers. Its popularity has grown and grown.’