[hummus_bae]

If they’re pressure-sensitive they won’t work while the lid is closed… so they’d have to be capacitive.

[jmull]

I don't know what that means. What lid? And why would a lid cover the sides of a phone?

Even a case fully covering the sides could have a bump in the right place, to serve as a target for the user and transmit force to the phone's force sensor.