Beetles inspire a new generation of technology

Licensing opportunity

An insect that sprays its predators with toxic steam has inspired scientists at Leeds University, UK in research to develop new types of nebulisers, needle-free injections, fire extinguishers and powerful fuel injection systems.

The work, funded initially by the Engineering and Physical Sciences Research Council, and subsequently by Swedish Biomimetics 3000, examined mechanisms at work in the bombardier beetle.

The 2 centimetre long beetle defends itself against all-comers – frogs, spiders, birds and insects – with a cocktail of steam and stinging chemicals which it can blast for distances of up to 20 centimetres from a combustion chamber which is less than 1 millimetre long.

The chemical and physical characteristics of the spray and the insect’s physiology were simulated using a scaled-up experimental rig in Leeds. The rig uses heating and flash evaporation techniques to propel a variety of liquids, and its 2-centimetre chamber can blast the fluid for up to 4 metres or at the other extreme produce a ‘soft mist’ with droplets as small as 2 micrometres.

From this, the team, led by Professor of Thermodynamics and Combustion Theory Andy McIntosh, has developed, µMist, which has the potential to become the platform for the next generation of more effective and eco-friendly mist carrier systems.

The µMist spray technology enables fine control of droplet size, temperature and velocity. Applications include fuel injection, medical drug delivery systems, fire extinguishers and fire suppression.

McIntosh likens the beetle’s defence mechanism to a pressure cooker controlled by a complicated system of valves. “Nobody had studied the beetle from a physics and engineering perspective as we did – and we didn't appreciate how much we would learn from it.”

There are 500 species of bombardier beetle, mostly found in Africa, Asia and South America. Their fluid chambers typically react hydroquinone with hydrogen peroxide to produce a fiery blast of steam, though different species use slightly different combinations of exhaust nozzle arrangements.

Swedish Biomimetics 3000 Ltd a philanthropic organisation that funds translational research of biomimetics concepts to the point where they are commercially viable. The company will then seek corporate partners to further develop the technology. The company has signed a worldwide exclusive licensing agreement for the development and commercialisation of the µMist technology and potential applications have been filed for patents.