This is totally crazy! Aliaksei Zholner built a very small one cylinder machine out of paper. And then he opens it to show us his news, even more tiny paper-machine. And it is even working!
“The model is completely made of paper
LxWxH: 18 x 13 x 22 mm
Shaft diameter: 0.5 mm
Piston stroke: 3 mm
Cylinder diameter: 3 mm
“Swept volume”: ~ 21 mm3″
More about the building process can be found here.