Piezo-resistive silicon pressure sensor

Fig. 5.59 shows a section through a Piezo-resistive silicon pressure sensor. The ambient pressure is applied from above, while the pressure being measured is applied from below. A silicon membrane that deforms under the pressure is applied to a silicon carrier structure. Piezo-resistive structures are fitted in the membrane, which then change their resistance accordingly when the membrane deforms. A bridge circuit generates an electrical output signal which is proportional to the difference in pressure. 

Figure 5 Silicon semiconductor piezo-resistive pressure sensor. (Chau et al., 1999, with permission of CRC Press.)...

Piezo-resistive pressure sensors (Figure 7.3) make use of silicon membranes with integrated strain gauges that are generated in a semiconductor process. In this way low-cost sensors can be produced. These are not corrosion-resistant but they can be protected by a separating metal diaphragm. 

---