3D Printed… micro-thing… with still-beating rat heart-cells embedded in it (like an Aztec Sacrifice), to make it go.
The idea is that these could be used for “search and rescue” missions within the human body… which is good news if you’re a human maybe, but the most fucked up shit you can imagine if you’re a rat. It’s Room 101 on some very weird acid indeed.
Impressive though… I just wish they’d find some way of doing this with drosophila rather than rats. Rats are people too.