When thinking about the interaction mode of the switch, I thought of the embarrassing experience of using the infrared sensor faucet in public places before, because the location of the infrared sensor in each place is different, and it takes some time for the faucet in some shopping malls to get out of the water, so I often wonder whether the faucet is broken or I put it in the wrong place. The original intention of designing this faucet is to have a falling feedback before the water comes out. The style after removing the infrared sensor can also be used as a writer, with the faucet itself as the switch. Improved the previous design.