I’d like to suggest a touch sensor that is based on a normally open single pole single throw momentary contact switch for use with mobile robots in situations where physical contact is required rather than measuring distance with a ranging sensor.
Ideally one could connect multiple switches to a multiplexer to determine which switch was pressed. The use case for this scenario would be when one wants to detect contact on any side of a robot without taking up multiple connections on the board. I would propose using an analog port on the connection rather than a digital one so that the value returned by the multiplexer could be used in the code to identify which switch was pressed.