It's an interesting machine, with it's shutter. Here's a direct link to the paper: http://arxiv.org/ftp/arxiv/papers/1304/1304.1334.pdf I hate exaggeration in sci news, (50 nm)^3 is a minimum spot size of about 10,000,000 atoms, or 50,000 of atoms if they do a single atom thick deposition. Also, Standard FIBs can already deposit gold and other things using a deposition gas injector, with similar resolution and speed, and no aperture to clog. A Russian group drew images of characters in a similar way in 2006, with apertures, with the same resolution. ("Atom 'Pinhole Camera' with Nanometer Resolution" [Russian translation: actually a pinhole lithographic projector], V.I.Balykin et al, link: www.researchgate.net/publication/226645891_Atom_pinhole_camera_with_nanometer_resolution/file/d912f50a8a891ad5e2.pdf)

Congratulations, Orthonormal. I am the engineer who designed the CAPS electronics ten years ago. You have "broken into" a really simple, completely unsecured system.

Please leave the carts unlocked when you are done playing. If you screw them up, you are stealing from stores that don't make much of a profit margin. And from the company (actual human beings) that did something about carts being left all over neighborhoods. They don't make much money, either. Retrieving carts turns out to be a significant expense for stores. There are companies that charge money to pick them up (Which always seemed like a potential protection racket to me.)

If that's you modeling the system in the instructables article, I'm in love. Brains and beauty.

As far as "On the one hand, we feel sorry for the engineer who has to figure out why thunderstorms are setting off a byte-encoded trigger for the locking mechanism. On the other hand, HAHAHAHAHAHA!" Sorry, but I had to tell Carttronics LLC about your prank.