- Task 2 Mems Pressure Sensors Can Be Used For High Sensitivity Accurate And Precise Measurements Mems Sensors Can Be M 1 (115.88 KiB) Viewed 15 times
Task 2: MEMS pressure sensors can be used for high-sensitivity, accurate and precise measurements. MEMS sensors can be made in micron scale, unseen by the naked eye, with all the instrumentation system elements implemented on the same chip. It is standard to make a Silicon diaphragm as shown below, which has a cavity underneath to insert the gas to be measured. Moreover, the deflection of the diaphragm can be easily measured by fabricating strain-gauges (not adding them on top, but literally modifying silicon by adding impurities to transform it into a strain-gauge material with extremely high gauge factor]. Given that the 4 strain gauges shown are connected in a single Wheatstone bridge circuit, answer the following: A. Is the temperature or heating problem compensated for in this configuration? B. Draw the circuit diagram of the strain-gauges, specifying the placement of strain-gauges 1, 2, 3 and 4 shown in the sketch on the circuit diagram. Mark each one with the corresponding strain being tensile or compressive [the diaphragm deflects upwards). C. If the strain-gauge material is n-type Silicon with a gauge-factor of 175 and an initial resistance of 1 KOhm. What is the new resistance of each strain-gauge if the strain is 0.2%. D. If the output of the given sensor is represented as v = 3.14*pº.3, where v is the output voltage in volt and p is the input pressure in Pascal. The pressure value changes from 0 to 1 MPa. Define the pressure range through which this sensor performs the best.