An interesting side note here. The floor buttons in the lifts in my employer's building actually work by detecting the minute electrical charge the human body has. You can press on them as hard as you like with something plastic or wooden and nothing will happen. Not even fingernails will do it. But the slightest contact from bare flesh or something metal you're holding will activate it.

This can be a bit annoying if you have your hands full, but apparently they were specified that way as a security measure.

For what reason, I don't know.

Bea"Trying to get a finger stuck out when holding a monitor is dang difficult"sty