Measure mechanical pressure as a varying voltage.
A pressure pad (i.e. force-sensing resistor, or FSR) is a contact sensor in which the resistance changes in response to mechanical pressure. The resistance decreases with increased force. A voltage divider circuit can be used for forming a voltage which depends on the pressure.
Commercial FSRs can be damaged by excessive force. In practice, it can take care to design them within a mechanical assembly so they are not directly exposed to excessive force or forces which pull them apart. But they are a relatively cheap and robust way to make an analog human interface.
As a challenge, rather than use a packaged FSR device, make your own using tape and conductive fabric. Please see the following as a guide.
Conductive fabric can also be damaged by excessive force and can some types can wear out from washing. But these sensors can be incorporated into clothing, made with multiple sensitive points, turned into tilt sensors and linear controls, etc.