This version (2019) is easier to reproduce and is based on a PCB. However, the motor is too weak for viscose sucrose solution.  
  Part of: Keller O, Appelhoff S, Paffhausen BH, Wenzel T (2023) Development and Sharing of Open Science Hardware: Lessons Learned from Wikimedia Fellowships. Research Ideas and Outcomes 9: e95174. https://doi.org/10.3897/rio.9.e95174