For wannabe thieves, nothing is more tantalizing than an empty street and a vulnerable ATM. Soon, though, they could be facing more than just failure. Taking design cues from mother nature herself, researchers are building ATMs that fend off thieves with a spray of hot, steaming foam. 
 
 The inspiration for this dastardly defense mechanism comes from none other than the bombardier beetle, which sprays near-boiling acid at any foes who coming knocking. It keeps the ingredients for its deadly concoction (hydrogen peroxide and hydroquinone) in two separate chambers in its abdomin. That way, the chemicals don't mix until they come shooting out, at which point the resulting reaction heats up and nearly vaporizes the noxious liquid. Here's our little friend in action. 
 
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 Researchers at ETH Zurich University took cues from the deadly beetle and built two chemical filled honeycomb chambers. Except this time, hydrogen peroxide was paired with manganese dioxide. Since the two are only separate by a thin sheet of lacquer, any tampering will cause the chamber to break immediately, triggering a reaction that produces water vapor, oxygen, and heat. A much less expensive—not to mention non-face melting—variation on the bomardier's own tactics. 
 
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 Even though the thief might not walk away with a half-eaten face, this is a much more effective way of rendering ATM-theft useless. The oozing foam from the reaction will be laden with dye, marking the banknotes (rendering them useless) as well as the thieves themselves. What's more, researchers say that including DNA nanoparticles will allow them to trace the cash back to the source. Thieves may be able to run, but thankfully, it's getting much harder for them to hide. 
 
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 Hopefully that barrier is thick enough to withstand the occasional (and inevitable( innocent, frustrated shake. And while this all still just being tested—no plans for immediate rollout yet—we could all use a few more acid-spitting objects in our lives. [Journal of Materials Chemistry via The Atlantic] 
 
 Image: Getty Images/Sion Touhig ||||| The bombardier beetle inspired the researchers of ETH Zurich. (Photo: jayvee18 – Fotolia) 
 
 Its head and pronotum are usually rusty red, and its abdomen blue or shiny green: the bombardier beetle is approximately one centimetre long and common to Central Europe. At first glance, it appears harmless, but it possesses what is surely the most aggressive chemical defence system in nature. When threatened, the bombardier beetle releases a caustic spray, accompanied by a popping sound. This spray can kill ants or scare off frogs. The beetle produces the explosive agent itself when needed. Two separately stored chemicals are mixed in a reaction chamber in the beetle's abdomen. An explosion is triggered with the help of catalytic enzymes. 
 
 “When you see how elegantly nature solves problems, you realise how deadlocked the world of technology often is,” says Wendelin Jan Stark, a professor from the ETH Department of Chemistry and Applied Biosciences. He and his team therefore looked to the bombardier beetle for inspiration and developed a chemical defence mechanism designed to prevent vandalism – a self-defending surface composed of several sandwich-like layers of plastic. If the surface is damaged, hot foam is sprayed in the face of the attacker. This technology could be used to prevent vandalism or protect valuable goods. “This could be used anywhere you find things that shouldn't be touched,” said Stark. In agriculture and forestry, for example, it could be used to keep animals from gnawing on trees. 
 
 Like a fuse 
 
 The researchers use plastic films with a honeycomb structure for their self-defending surface. The hollow spaces are filled with one of two chemicals: hydrogen peroxide or manganese dioxide. The two separate films are then stuck on top of each another. A layer of clear lacquer separates the two films filled with the different chemicals. When subjected to an impact, the interlayer is destroyed, causing the hydrogen peroxide and manganese dioxide to mix. This triggers a violent reaction that produces water vapour, oxygen and heat. Whereas enzymes act as catalysts in the bombardier beetle, manganese dioxide has proven to be a less expensive alternative for performing this function in the lab. 
 
 The researchers report that the product of the reaction in the film is more of a foam than a spray when compared to the beetle, as can be seen in slow motion video footage. Infrared images show that the temperature of the foam reaches 80 degrees. Just as in nature, very little mechanical energy is required in the laboratory to release a much greater amount of chemical energy – quite similar to a fuse or an electrically ignited combustion cycle in an engine. ||||| Megan, a reader who voted for Hillary Clinton, shares a powerful confession: 
 
 I’ve been thinking about the election a lot for the past two days, and the idea that I keep coming back to is that in some ways this is my fault. 
 
 It’s my fault because I voted for Clinton when she ran against Obama in the 2008 primary, but I didn’t tell anyone because she was the unpopular choice. I wasn’t embarrassed about my decision, but being a real liberal seemed to mean voting for Obama. So I voted quietly in the primary, felt my disappointment quietly when she lost, and seamlessly joined the Obama supporters in the general election. 
 
 It’s my fault because I voted for Clinton when she ran against Sanders in the 2016 primary, and I didn’t tell anyone because again she was the unpopular choice. She was even more qualified this time around and I had a greater appreciation for the depth of her public service, but being a real liberal seemed to mean supporting Sanders. So I voted quietly in the primary, and rarely mentioned my preference for her. 
 
 It’s my fault because during the long months of the primary and the general election I didn’t tell anyone how strongly I felt about Clinton. I didn’t put a sticker on my car, I didn’t put a sign in my yard, and I didn’t wear a T-shirt. My loudest statement of support was the tiny pin I purchased after the convention, at a time that it felt safe to be a Clinton supporter. 
 
 It’s my fault because when I ran into people who were voting for Trump—at the grocery store, in the gym, in my neighborhood—I changed the subject because I didn’t want to get into an argument. I told myself that it wasn’t worth it and that they wouldn’t change their minds. 
 
 It’s my fault because though I knew my mother was genuinely torn between the two candidates I didn’t engage with her. I didn’t want to know that she actually thought there was a real choice to be made. 
 
 It’s my fault because I never once asked my sister what she was thinking. She’d supported the Tea Party in the past, and I assumed she was leaning towards Trump. I didn’t want to know. 
 
 It’s my fault because my father and I had a massive fight about Clinton over Easter, and in an effort to preserve our relationship I stopped talking to him about politics. If we didn’t talk about it, then I didn’t have to deal with the possibility that he was sexist and racist in a way I’d never considered. 
 
 It’s my fault because I capitulated to the expectation that I not express my emotions publicly. I’m upset right now, and it isn’t lost on me that expressing this upset is potentially disqualifying. It isn’t lost on me that saying I’m angry will make me vulnerable to the accusation I’m too emotional. I’ve spent a lifetime calming down. It’s something that I try to do when interacting with men professionally, and it’s something that I try to do when I interact with men personally. And every time I do this in my private life, I normalize it and make it harder for women to succeed in public life. 
 
 And it’s also my fault because when I did support her, I did so in a provisional and caveated way. I said things like, “I realize she’s not a perfect candidate” and “I’m not arguing that she isn’t flawed.” And every time I said something like this I affirmed that there was a need to apologize, I singled her out as somehow different from other candidates (in both parties) who were worthy of unequivocal support, and I created the space for the impression that she was critically flawed. I did this nearly every time I spoke about her, and I saw this language in dozens of articles and editorials and statements of support (including The Atlantic’s editorial, though there doesn’t appear to be similarly caveated language in the Lincoln or Johnson endorsements). In fact, I don’t remember seeing this type of language in the editorials written for any of the similarly flawed men who have run for president over the past twenty years. And this, I think, is the thing I regret the most.
– The ATM is getting a lesson in self-defense—from a bug. Researchers in Switzerland were inspired by the bombardier beetle, which shoots out a gas that can burn skin, the Atlantic reports. The beetle's mechanism works by mixing two chemicals normally kept separate in its abdomen. When under attack, the beetle combines the hydrogen peroxide and hydroquinone to spray its attack gas. The researchers copied this system by putting hydrogen peroxide and manganese dioxide side-by-side, separated by only a lacquer. Break that lacquer, and you get the reaction. ATM makers could employ the principle in their machines by rigging them to ooze foam if someone begins tampering, say the researchers. Instead of burning acid, the ATMs could cover bills with dye and DNA, making the cash hard to use and easy to track. "Thieves may be able to run," notes Gizmodo, but "it's getting much harder for them to hide." In fact, the mechanism "could be used anywhere you find things that shouldn't be touched," a researcher tells ETH Zurich—whether to fight vandalism or keep animals off crops. (Click to read about another odd method of self-defense in the animal kingdom.)