A silicon-based pressure sensor measures an applied pressure by detecting the effect of the pressure against a silicon substrate. Strain gauges, in a silicon-based pressure sensor, are not bonded to, but etched onto a silicon substrate. Notice that the silicon substrate is not connected to the diaphragm via any mechanical transmitter, rather a transmission fluid (oil) is used to transmit the pressure from the diaphragm to the silicon substrate.

As an applied pressure pushes against the diaphragm, the transmission fluid presses against the silicon substrate. As the silicon substrate experiences deformation, the strain gauges, which are etched onto the silicon substrate, register this change.

As with bonded, foil strain gauge-based pressure sensors, strain gauges in a silicon-based pressure sensor are arranged in a Whetstone-bridge circuit formation. The bridge circuit detects any change in electrical resistance, which occurs once strain gauge has been bent due to deformation of the silicon substrate, as a deflection from the initial zero voltage leading. The deflection means the applied pressure to the sensor has changed.

Note: Honeywell uses bonded foil strain gauges, bonded semiconductor strain gauges, gauged silicon substrates and sputtered technologies in its pressure sensors, depending on which is most suitable for the application.