Clean Your Hands with a Sneezing Sanitizer Dispenser
Sneezes are typically associated with being sick, but YouTuber Nina has created a sanitizer dispenser that sneezes to clean hands.
The idea
Countless public spaces are now equipped with automatic hand sanitizer dispensers that place a drop of alcohol-based disinfecting gel, which aims to kill any bacteria and viruses that might be on one's hands. However, YouTuber Nina, who goes by the username achNina, wanted to make this otherwise boring method of delivering drops of sanitizer more intriguing by housing the automated mechanism within a giant 3D-printed human nose that would sneeze on unsuspecting victims.
Electronic components
Perhaps the most important aspect of this project was getting the nose to automatically recognize whenever a hand is placed underneath so that sanitizer could come flooding out. For this, Nina chose a widely-used infrared distance sensor module that sends out an analog voltage depending on how much IR light is reflected back to the receiver from the emitter. This value is then read by an ESP32's ADC and triggers the dispensing mechanism if a threshold is reached.
Building a nose
The nose was designed with the help of Fusion 360 and features a couple of openings at the base for the IR sensor and to drop out hand sanitizer. Nina also created a custom mount that has a slot for a micro servo motor along with a holder for a pump-style bottle.
Cleanser dispensing
This solution seemed to work at first, but subsequent testing showed that the servo motor was unable to press on the bottle when it was attached within the nose. So rather than going with the more traditional bottle, Nina instead opted for a liquid spritzer that already contained all of the necessary components that made it as easy as pressing a button with the original servo motor.
Sneezing out some sanitizer
Once fully assembled, Nina loaded her code onto the ESP32 that was responsible for reading the IR module and dispensing the liquid disinfectant. It not only performs this action, but even plays a loud sneezing noise to really drive home how gross this concept seems. To see more about this project, you can watch its demonstration video/build log here on YouTube.