Addresses of All Authors

Andy C. McIntosh, School of Chemical and Process Engineering, University of Leeds, LEEDS, UK.

Joseph Lawrence, 102, Brookwood, Starkville, Mississippi, USA.

Author's Biography

Andy McIntosh is currently a visiting research professor in Thermodynamics and Combustion Theory at the University of Leeds, and an Adjunct Professor at the Department of Agricultural and Biological Engineering. Mississippi State University. He has lectured and researched in these fields for over 30 years with a PhD in combustion theory and a DSc in Applied Mathematics. He is a Fellow of the Institute of Mathematics and its Applications, the Institute of Energy, the Institute of Physics and the Royal Aeronautical Society. A chartered mathematician and engineer, and author of over 190 papers and articles, his research is in combustion in fluids and solids, and latterly he has been involved in research in the area of biomimetics where the minute combustion chamber of the bombardier beetle has inspired a patented novel spray technology with applications to fuel injectors, pharmaceutical sprays, fire extinguishers and aerosols. This research was awarded the 2010 Times Higher Educational award for the Outstanding Contribution to Innovation and Technology.

Dr. Joseph Lawrence is involved in research focused on understanding the dynamics of human body responses to trauma through multiscale modeling. His primary work has been in the area of traumatic brain injury, where he utilized Finite Element (FE) simulations of the human brain under large strain and blast related scenarios. He has also co-lead Mississippi State University’s efforts on the multiscale modeling and engineered design using biomimetics, specifically in the design of helmets and other protective aspects for transportation and sports applications. More recently, he has begun collaboration with Professor McIntosh in the biomimetics of the bombardier beetle’s valve system and hydrogen peroxide production.


The innocuous looking bombardier beetle is one of the most remarkable creatures in the insect world. This tiny insect (1-1.5 cms long) is able to fight off any spider, frog, ant or bird that comes too close, by blasting the attacker with a powerful jet of hot, toxic fluid. Furthermore, the beetle can aim its weapon in any direction (even over its head) with pinpoint accuracy, and can reach distances of up to 20 cm with its spray. The bombardier beetle is rare in Europe but common in Africa, Asia and the warmer parts of the Americas, and in order to resist predators, forms a noxious spray by reacting small amounts of hydroquinone with hydrogen peroxide in a pair of combustion chambers in its abdomen, and in the presence of the catalysts catalase and peroxidase.

The beetle demonstrates irreducible complexity in the following systems: 1) the sensory mechanism which gives awareness of the approach of a predator, 2) the valve system that involves both inlet and exhaust valves working synchronously, 3) the chemical production of reactants hydrogen peroxide and hydroquinone, 4) the use of catalytic chemistry to eject a controlled explosive mixture, and 5) the moveable, flexible exhaust turret to enable ejection in any direction. These and others are systems which only work when each of the component parts are operating in harmony with others in a coordinated mechanism. For chemical systems the same point applies in principle. The overall chemical system will only operate correctly if each component chemical is in place in a prepared pathway.

This paper reviews the research of a number of authors (including Professor McIntosh) into the workings of the bombardier beetle spray system. Not only is this is a classic example of biomimetics (the study of design in nature and copying these designs and using them in engineering), but also tacitly underlines the necessity of design in the original beetle itself. The discovery that the McIntosh team made of sophisticated mechanisms in the beetle’s structure and chemistry demonstrates the irreducible complexity in the design of the beetle.


Biology | Engineering


biomimetics, biology, engineering, design, irreducible complexity, pulse combustion, valves, hydrogen peroxide





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