The last “world’s smallest chess set” with pieces was a relatively gargantuan 2.5 mm by 3.5 mm. A mere trifling.
How does 435 μm by 435 μm sound to you (that’s micrometers, or .435 mm)? With pieces? And a robotic arm to automatically move the pieces?
That’s what Texas Tech did for the winning design entry for a university competition in microelectromechanical systems (MEMS) at Sandia National Laboratories.