Steaming beetle inspires spray technologies

Inspired by the 2cm long Bombardier beetle, researchers at the University of Leeds have developed a technology called “µMist” which has the technology to become the basis of new nebulisers, needle free injectors, fire extinguishers and fuel injection systems.

The beetles use chambers less than 1mm long in which they typically react hydroquinone and hydrogen peroxide to produce a blast of steam and stinging chemicals to over distances up to to 20cm to drive away predators. The researchers at Leeds, led by Andy McIntosh, Professor of Thermodynamics and Combustion Theory, have developed a rig with a 2cm chamber that uses heat and flash evaporation technique to propel a variety of liquids over distances of up to 4m or produce a mist with droplets as small a 2 microns. Professor McIntosh’s research was inspired by entomologist Prof Tom Eisner of Cornell University, who has studied the beetles over a number of years. Slow motion pictures shot by Eisner showed how the bombardier beetle expels fluid through a series of rapid pulses. The pressure in the insect's fluid chamber causes the liquid to be ejected, followed by a drop in pressure, which allows more fluid to enter and the pressure to build up once more. For more information: http://www.epsrc.ac.uk/PressReleases/BeetlesInspireNewGeneration.htm