Also of potential interest is Kempe's Universailty Theroem which states you can draw any (polynomial) shape with a set of mechanical linkages. Like one that will sign your name.

https://academic.oup.com/plms/article/s1-7/1/213/1570315?log...

http://www.koutschan.de/data/link/

damn, I got nerdsniped again