Ben Krasnow is one of those people no one has a bad opinion of. He’s part of the team at Verily (Google’s Life Science Alphabit), where he’s busy curing cancer. He co-founded Valve’s hardware division and his YouTube channel, Applied Science, is an exploration of building very high-tech tools very quickly and on a very low budget. Ben has built everything from an electron microscope to a liquid nitrogen generator to a robot that makes individual chocolate chip cookies with ingredients in different proportions. He’s curing cancer and finding the perfect chocolate chip cookie recipe.

The focus of Ben’s talk at this year’s Hackaday SuperConference is building low-cost scientific apparatus quickly. From Applied Science, Ben has cemented his position as a wizard who can find anything either on eBay or at a surplus store. The real trick, Ben tells us, is getting his boss and accounting to understand this rapid prototyping mindset.

The first build Ben walked the SuperCon through was a device to test a hypothesis. Were X-ray backscatter machines, the devices found at airport security lines from about 2009 to 2013, actually effective at stopping terrorists? Although there are obvious safety and civil liberties questions raised by assessing X-ray backscatter devices, this is simply a question on the effectiveness of the TSA’s fanciest new gear. Do X-ray backscatter devices stop terrorists more effectively than a metal detector?

The answer to this question came in a one-month build. Even at the beginning of the build, Ben says he didn’t know much about X-rays. Backscatter X-ray machines aren’t like what you would find at a dentist’s office – those are transmissive X-rays, and giving millions of flyers X-rays every day would be a worldwide health crisis.

Instead of shooting X-rays through everyone who goes through a TSA checkpoint, backscatter X-rays operate on an entirely different principle. After a quick patent search, Ben found a very good description of what backscatter X-ray scanners do, and began work on constructing a prototype to assess the effectiveness of these devices.

The build consisted of an X-ray source easily found on eBay, a phosphor screen found on eBay, a photomultiplier tube found on eBay, and a few bits and bobs kicking around the junk bin in the shop. Although you can simply buy a Rapiscan Backscatter machine (taken from an airport on eBay), that would cost several thousand dollars. Ben only spent a few hundred on his machine.

After building a device to scan an object with X-rays and detect the reflected photons, Ben had a working backscatter X-ray machine. It successfully detected an Allen key being smuggled by a chicken onto a plane. It’s a simple setup, but it proves you can make very complex devices very easily using parts bought on eBay.

The take away from Ben’s talk is simply rapid prototyping. Iterate often, find all the information that’s readily available online, and build prototypes quickly. Leverage the availability of everything being for sale somewhere. Build first, and ask questions later, and you might have the time to discover the perfect cookie recipe.