Rolling button / Public elevator

Buttons in the elevator tend to be contaminated easily.
However most people are unaware of this seriousness and do not care about it too much.
Research shows that buttons in the elevator have 40 times more germs per square centimeter than toilet has.
Therefore we need buttons that can keep our hands hygienic.
‘Rolling Button’ can be a solution for this problem using UV light.
Buttons work when you roll the button downward.
At the same time, the part you touched moves backward and ultraviolet light sterilizes the contaminated part. The sterilized part of the button is exposed when someone rolls the button again.