From the horse’s mouth,
“In this lithography experiment light creates free radicals from phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide which induce polymerization of 1,6-hexanediol diacrylate.”
Or for those without a Chemical Engineering degree, light from a (high resolution) projector interacts with a special liquid, producing a hard polymer on the surface. A platform within the liquid is lowered, taking the layer of polymer with it. Shine the projector again to produce another layer: lather, rinse, repeat. Long story short, an atypical 3D printer using light on a very small scale.
You get the chemicals and lab equipment, we’ll get the laptop and projector, and for goodness sake [Jimmie] stop bumping the table.
As the video above shows, [Zach Hoeken] is continuing to improve on his peristaltic pump design. The moving parts in peristaltic pumps never contact the fluid being moved. Instead, they interact with the outside of the tubing that’s carrying the liquid. In [Zach]’s design, multiple skate bearings roll across the outside of the silicon tubing, squeezing the liquid through. You can get a better idea of how this works by watching the first video. The newer version appears to be pumping much better. We’re not sure if that’s because of faster motors or from switching to two bearings instead of three. This definitely looks like a good choice if you’re planning on building your own cocktail robot. You can find the plans on Thingiverse.