MEMS and sensors

Which correctly describes the piezoresistive effect used in semiconductor pressure sensors?

  1. AThe electrical resistivity of a material changes when mechanical stress is applied
  2. BA voltage appears when light shines on it
  3. CThe direction of current is bent by a magnetic field
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Answer: A. The electrical resistivity of a material changes when mechanical stress is applied

Silicon shows a strong piezoresistive effect, in which its resistivity changes greatly under stress. Resistors are built into a thin membrane (diaphragm) that deforms under pressure, and the change in resistance is detected with a bridge circuit, converting pressure into an electrical signal.

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