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Accelerometers tutorial

Modules

1. Introduction to Acceleration Measurement
2. Piezoresistive Accelerometers
3. Capacitive Accelerometer

pages: 1 2 3 4 5 | next

Principle employed by a simple form of a piezoresistive accelerometer is shown in the following figure:

Basic features:

  • Sensitivity to off-plane accelerations
  • Spring-mass system is embodied as a silicon cantilever beam with a silicon proof mass attached to the free end
  • Silicon cantilever thick as 15 μm is equipped
    • on one side with a piezoresistor
    • on the other side with a proof mass of a thickness 200 μm
  • Rest of a silicon substrate surrounding the seismic mass serves as an accelerometer base
  • Upper face of the accelerometer is closed by glass or silicon plate (not shown in the figure) in order to protect the sensible part
  • If acceleration is applied on a sensor, the movement of the seismic mass bend the cantilever.
  • Value of piezoresistor resistance, which varies due to varying mechanical stress in the cantilever, is then measured.
  • This kind of sensor was used for measurements in the scale from 0.01 g to 100 g.

1. Introduction to Acceleration Measurement
2. Piezoresistive Accelerometers
3. Capacitive Accelerometer

pages: 1 2 3 4 5 | next

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