A beetle that uses gas explosions to chase off predators has inspired a new ATM defense tactic.
The bombardier beetle doesn't look very threatening, but it possesses an extremely aggressive chemical, an ETH Zurich news release reported.
When the beetle is threatened it emits a popping sound and releases the caustic spray, which has the ability to kill fire ants. In this process two chemicals are stored in different parts of the and then mixed in a reaction chamber before release.
"When you see how elegantly nature solves problems, you [realize] how deadlocked the world of technology often is," Wendelin Jan Stark, a professor from the ETH Department of Chemistry and Applied Biosciences, said in the news release.
Researchers had the idea to model an artificial chemical defense system after the one exhibited by the beetle. The device would be used to prevent vandalism and ATM theft.
The mechanism would be made up of "sandwich-like" plastic layers; if these layers were damaged hot foam would be sprayed into the attacker's face.
To create this device the researchers used plastic films that had a honeycomb-like structure. Two of these structures were layered on top of each other and the hollow spaces of each were filled with either hydrogen peroxide or magnesium dioxide. A clear lacquer was used to separate the two layers, each containing a different chemical.
When the interlayer separating these chemicals is destroyed it causes the chemicals to mix, causing a "violent reaction that produces water vapour, oxygen and heat," the news release reported.
The bombardier beetle uses enzymes for this defense, but magnesium dioxide would be a less expensive option.
The temperature of the foam can reach 80 degrees, and comes out very strong despite using very little mechanical energy.
"This could be used anywhere you find things that shouldn't be touched," Stark said.
