Worm-robot with 3D-printed linear actuators
http://zurich.fablab.ch/2016/02/3d-printed-worm-bot-presentiert-im-fablab-zuerich-aruduino-workshop/
https://hackaday.com/2016/02/11/robot-does-the-worm-to-get-around/
https://github.com/tscha70/3DPrinterSTLFiles/tree/master/wolly/Wolly_OrderSetWolly_with_Joints
https://www.youtube.com/watch?v=1Dicb3sjylI