3. Ambivalent sensors

3.1 Piezoelectric transducers

The phenomenon of piezoelectricity is manifested by the appearance of electrical polarization in certain anisotropic dielectric materials (absence of a center of symmetry in the crystalline lattice) when they are deformed under the effect of a force of suitable direction. If we create a capacitor by placing a pair of armatures on opposite sides of a piezoelectric plate, a force will produce charges of opposite signs on the opposing armatures, resulting in a potential difference proportional to the force applied. A device of this kind can be used to measure forces and any physical quantities likely...