High-sensitivity Pressure Sensor Research Articles

High-sensitivity pressure sensor using a shielded polymer-coated fiber Bragg grating

We demonstrate a novel high-sensitivity pressure sensor, which is based on the use of a fiber Bragg grating (FBG) embedded in a polymer-filled metal cylinder with an opening on one side to enhance the pressure sensitivity. The measured pressure sensitivity of the fractional change in the Bragg wavelength of our experimental sensor is -3.41/spl times/10/sup -3/ MPa/sup -1/ which is approximately 1720 times higher than that can be achieved with a bare FBG. The linearity of our sensor is also good. This sensor should find applications in the area of low-pressure measurement.

Highly-sensitive pressure sensor based on W-lighguides

A highly sensitive pressure sensor based on two Mach-Zender interferometers is described. The interferometer measuring and reference channels are made of single-mode W-lightguides. The measured sensitivity was shown experimentally to be 65·10−2 dB·P−1·m−1.

Design of high-sensitivity photoelastic optical fiber pressure sensor: a differential approach

A differential method is described for an optical fiber photoelastic pressure sensor to implement high sensitivity and low drift optically. The method relies on importing two orthogonal polarization light beams into the system alternately in time to produce two differential output signals that are derived from conventional compensation methods. The difference of the two output signals can reduce the long-term drift significantly. The measurement range of 0/spl sim/0.15 MPa has been demonstrated with an accuracy of 0.1% within the temperature range of -20/spl deg/C/spl sim/50/spl deg/C. The practical application proves its efficiency.

High-performance piezoresistive pressure sensors for biomedical applications using very thin structured membranes

High-sensitivity pressure sensors for invasive blood pressure measurements are described. To reduce the unavoidable nonlinearity increase with sensitivity, structured membranes are used. A novel technology based on electrochemical etch-stop and n-diffusions with different junction depths is used to obtain bosses of reduced thicknesses. Based on this technology new structures for pressure sensors have been assessed. The results show that these devices exhibit performances impossible to achieve with classical designs based on flat diaphragms.

Low-cost high-sensitivity integrated pressure and temperature sensor

Abstract A resistive temperature detector along with a capacitive pressure sensor using a silicon membrane have been integrated on a glass substrate. The metrological characteristics of this miniaturized sensor feature a pressure sensitivity of 1.29 pF/bar between 1 and 6 bar and a temperature sensitivity of 6200 ppm/°C between −40 and +130 °C. In the pressure and temperature ranges considered, the main cause of error is non-linearities that generate imprecisions less than or equal to ±3% of the full scales. The technological process allows these new devices to be batch produced.

Ga1−xAlxAs material for high-sensitivity pressure sensors

The resistivity of n-type Ga1-xAlxAs alloys has been found to be very sensitive to both the purely hydrostatic and small nonhydrostatic pressures. For some alloy compositions, the resistivity variation with pressure is almost linear. For typical alloy composition x = 0.23, the coefficients are ~ 1.7 kbar-1 and ~ -0.15 kbar-1 for low (P - 18 kbars) and high pressures (P > 18 kbars), respectively. For the same composition, the temperature coefficients of resistivity are ~ 4.3 × 10-3 K-1 and ~ 0.22 K-1 for temperature intervals 300 > T > 125 K and T < 125 K, respectively.