Hi Hacker News!<p>My gf is an ICU nurse and challenged me to build a device that helps people wash their hands properly (I wanted to build a ventilator, but she said that wasn't super helpful....:(<p>This is my first attempt, it's a soap dispenser that marks your hand with a stamp that fades with at least 20 seconds of hand washing—the minimum time recommended by the CDC.<p>Very open to comments both constructive and commending! :)