Low-cost Pressure Sensor Research Articles

Design and fabrication of a low-cost microengineered silicon pressure sensor with linearised output

The design and fabrication of a capacitive pressure sensor comprising two microengineered silicon wafers fusion-bonded together to provide a relatively low-cost pressure sensor is described. The sensor produces a capacitance change of around 100 pF for an applied pressure of eight bar. The capacitance change is measured using a charge redistribution technique. The sensor has been designed to enable subsequent linearisation within a microcontroller. The same microcontroller is also used to calibrate the device, implement a successive approximation register within the charge redistribution circuit, and drive an LCD resulting in an elegant and potentially low-cost system.

Low-cost surface mount pressure sensor

Low-cost surface mount pressure sensor

Media-isolated sensor

In pressure-sensing applications it is often desirable to expose the sensor to harsh media. Some applications, for example, gauge measurements, require exposure to harsh media from one side only, but others often require differential measurements between two locations. If the silicon piezoresistive pressure sensor is used in such an application, then the harsh environment could quickly corrode and destroy the unprotected side of the sensor. Historically, protection of silicon piezoresistive sensors from harsh media was provided by enclosing the sensor in an oil-filled compartment with stainless-steel diaphragms. This paper describes another approach to media isolation. An accurate low-cost differential pressure sensor has been developed using standard silicon piezoresistive pressure sensors, and does not require any oil filling for media isolation. It is in mass production for the automotive market now, but can also be used in many other non-automotive applications.

Intelligent and Low Cost Continuous Relative Density Measurement in Batch Fermenters

In this article we present two methods for the real time automatic measurement of the relative density. The first one relies on the heat generated during the fermentation which requires no additional sensors in the tanks. It is based on the thermal model of the tank and the only additional requirements are the measurement of the temperature of the surrounding air. The other method is based on two low-cost pressure sensors with an algorithm for autocalibration and compensation of temperature perturbation. The autocalibration is done during fermenter feeding and with only one manual measurement of the relative density.

Low-cost pressure sensor microsystem

Low-cost pressure sensor microsystem

A very low-cost pressure sensor with extremely high sensitivity

Abstract A new type of piezoresistive pressure sensor has been fabricated by polymer thick-film technology. The resistor bridge is screen-printed and cured onto a flexible substrate, which has been successfully used in hybrid technology for several years. Because of the high flexibility of the substrate, high sensitivity can be achieved at low cost. During the realization, several technological problems arising from the material characteristics of the substrate have to be overcome. The most difficult one is the appropriate handling of the flexible substrate during screen-printing, curing and soldering without generating built-in stresses. This is the reason why a new technology has in fact been developed. As a result, an extremely sensitive pressure sensor has been realized at a low cost.

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.

Polymer thick-film technology: A possibility to obtain very low cost pressure sensors?

Abstract A new type of pressure sensor has been developed by taking advantage of the piezoresistive effect in polymer thick-film resistors screened and cured on epoxi-glass diaphragms. The device looks promising to satisfy the requirements for low cost, high sensitivity and low thermal drift. The piezoresistive effect in polymer thick-film (PTF) resistors is discussed in comparison with cermet thick films. The possibility of making a high-performance PTF pressure sensor is theoretical supported. Characteristics of the newly developed polymer thick-film sensor are described. In a limited temperature range, the new sensor has parameters that are not worse than those of the cermet thick-film pressure sensor and a much lower cost.