Automatic hand sanitizer using a 9 gram servo, ultrasonic proximity sensor and arduino nano. The mechanism is very simple using only a string to push down on the cap of the hand sanitizer.
In depth tutorial: https://www.instructables.com/id/Simple-Automatic-Hand-Sanitizer-Soap-Dispenser/
3D print files: https://www.thingiverse.com/thing:4235115
Arduino code: https://drive.google.com/file/d/1OtrWPEkT9Di8dzfqBdbh0d4LK9d1ofnP/view?usp=sharing
For further questions feel free to contact me via e-mail.