Improved Sterile Elevator Button Design

My original trackball design is practical and cheap to implement but not 100% sterile. For the total germophobe crowd you could install a series of raised pairs of nibs housing electric eyes - each beam corresponding to a floor. Simply break the beam for your desired floor and there is no touching involved and your elevator ride is perfectly sterile except for the coughs, sneezes and other noxious emissions produced by your fellow passengers of course.

I considered a gesture based system a la MS Kinect but figured there would be too much potential for nonfunctionality for people like [Alterother]'s hillbillies or for those whose range of motion was restricted through disability or just an armload of packages. Anyone capable of using current lift buttons should be able to break the beam of an electric eye.

If you put the floor number label behind the beam even the dimmest passenger would unwittingly succeed in operating the lift by touching the label of their desired floor with their filthy, pestilence-ridden fingers. The rest of us would just swoosh our fingers through clean-ish air.

I would suggest having the pairs of nibs separated and offset a bit so punters don't activate multiple floors inadvertently (or on purpose).