In the summer of 2017, I built this zipper robot using 2 motors and a 3D printer. As its name says, it’s a cool robot that can both zipup and unzip a zipper. You can build one for yourself as well. I have shared the design of this robot as a .stl file at this link : https://hareshmiriyala.wordpress.com/2018/02/14/build-a-cool-zipper-robot/

Video of its working : https://www.youtube.com/watch?v=sx1RdgL3jXs
motors used : https://www.amazon.com/Torque-Speed-Geared-Electric-Motor/dp/B00HR4TWLU/ref=sr_1_5?ie=UTF8&qid=1510247646&sr=8-5&keyw