piezoresistiivinen

Piezoresistiivinen refers to the property of certain materials to change their electrical resistance when subjected to mechanical stress. This phenomenon is known as the piezoresistive effect. It is distinct from the piezoelectric effect, where mechanical stress induces an electrical voltage, or vice versa. In piezoresistive materials, the application of pressure, strain, or tension alters the material's internal structure, affecting the flow of electrons and thus its electrical resistance.

This effect is particularly pronounced in semiconductors like silicon and germanium. When these materials are deformed, their band structure can change, leading to significant variations in resistance. This sensitivity makes them ideal for use in various sensor applications. Piezoresistive sensors are widely employed to measure physical quantities such as pressure, force, strain, acceleration, and touch. For example, pressure sensors often utilize a diaphragm made of a piezoresistive material. When pressure is applied, the diaphragm deforms, causing a change in the resistance of embedded piezoresistors, which can then be measured and correlated to the applied pressure.

The magnitude of the piezoresistive effect is quantified by a property called the gauge factor. A higher gauge factor indicates a greater change in resistance for a given amount of strain. The development of microfabrication techniques has enabled the creation of highly sensitive and compact piezoresistive sensors, contributing to their widespread adoption in consumer electronics, automotive systems, industrial automation, and medical devices.