https://newatlas.com/mit-drone-chip/55116/

MIT's ongoing efforts to make flying drones ever smaller has passed a new milestone with the latest version of its Navion navigation chip. Essentially the brains for a drone the size of a honeybee, the chip measures just 20 square millimeters (0.03 sq in), which the researchers point out is about the size of a Lego minifigure's footprint.