Inspired by nature, scientists develop acid-firing ATMs

By Jack Flanagan on April 28th, 2014

The inauspicious bombardier beetle hides a rather large secret: its hindparts are a chemistry set of explosives. When the beetle is in trouble from, say, a greedy toad, a canister in its abdomen is filled with two chemicals. The mixture is poured into a second enzyme-filled canister which sets off an explosion of caustic acid. It’s enough to scare off even the hungriest predator.

“When you see how elegantly nature solves problems, you realise how deadlocked the world of technology often is,” says Wendelin Jan Stark, a professor for the Swiss Federal Institute of Technology (ETH) in Zürich. He believes that the bombardier’s apparatus for scaring off predators is so simple that it can be replicated in today’s technology.

Stark has set his sights on the humble ATM. A report on European ATMs shows the number of attacks on ATMs is rising. In the first half of 2013, there was around 10 million Euros stolen from more than 1,000 attacks.

Currently, ATMs already employ anti-theft measures – like marking stolen banknotes – but these rely on electricity. The main problem with electricity is that during a blackout, the ATMs suddenly become vulnerable.

The bombardier beetle’s explosive abdomen suggests that it’s possible to have these reactions without the use of electricity. In their experiment, the researchers in Zurich created a film of spray-on glue to separate two chemicals – Hydrogen Peroxide and Manganese Dioxide – which, when combined, become extremely hot (-80°C ) and bubbles (as the oxygen in the Hydrogen Peroxide is released).


The mechanism would break upon heavy pressure, such as someone kicking or attacking the ATM. At that point, the glue would shatter and the chemicals would mix, causing the heat reaction. Depending on the aims of the manufacturer, it could spoil the money or burn the attacker.

But this design isn’t just limited to a glue partition. Jonas Halter, one of the other researchers on the project, suggests there are a number of other possibilities. One example involves putting lacquered foil over the hydrogen peroxide. When the foil is scratched, it causes the reaction. He warns that using glue may be too fragile, and in need of rethinking.

The uses of the Bombardier beetle’s behind doesn’t end at ATMs, as Halter suggests that other uses could include transporting foods like fruit: “To protect vulnerable goods, they could cover them with the foil. Birds, for example, who cause problems by trying to eat the goods, get repelled when they pick at the foil.”

So next time you’re tempted to rob an ATM or “borrow” some fruit, be mindful of the insect-inspired acid that may come spewing out.