piezorezisztív

Piezoresistivity is a property of certain materials to change their electrical resistance when subjected to mechanical strain. This phenomenon is distinct from the piezoelectric effect, which involves the generation of an electric charge in response to mechanical stress. In piezoresistive materials, the applied stress alters the material's band structure or carrier mobility, leading to a measurable change in its electrical resistance.

The degree to which a material exhibits piezoresistivity is quantified by its gauge factor, which is the ratio of the relative change in resistance to the mechanical strain. Materials with a high gauge factor are more sensitive to strain and are thus preferred for sensor applications. Common piezoresistive materials include silicon, germanium, and some metals like polysilicon and metal alloys.

Piezoresistive sensors are widely used in various applications. They are integral components in pressure sensors, accelerometers, strain gauges, and load cells. For instance, in a pressure sensor, a diaphragm deflects under pressure, causing strain in embedded piezoresistive elements. This strain alters their resistance, and the change is measured and converted into an electrical signal proportional to the applied pressure. The sensitivity, linearity, and stability of these sensors make them valuable in fields ranging from automotive and aerospace to medical devices and industrial automation.