Field In-Ice Pressure Sensor Response Tests

1983 ◽  
Vol 105 (1) ◽  
pp. 6-11
Author(s):  
A. C. T. Chen ◽  
J. S. Templeton
Keyword(s):  
Pressure Sensor ◽  
Data Reduction ◽  
Broad Class ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Ice Sheet ◽  
Sensor Response ◽  
Sensor Output ◽  
Reduction Procedure ◽  
Ice Pressure

An ice pressure sensor has been designed and built at Exxon Production Research Company (EPR) to measure the pressure in an ice sheet. Laboratory and analytical studies were performed to establish a data reduction procedure to relate the pressure sensor output to the pressure in the ice sheet. However, because of the complex mechanical behavior of sea ice, the present experiment was conducted to validate this data reduction procedure. The validated procedure is considered applicable to a broad class of embedded ice pressure sensors. Field in-ice pressure sensor response tests were conducted near Prudhoe Bay, Alaska, between February and April of 1978. Twenty-two tests were conducted on three test blocks of ice to investigate the in-ice response of three ice pressure sensors. An ice block measuring 10 ft by 20 ft and of full thickness of the natural annual ice was cut free from the surrounding ice sheet after the pressure sensor was installed at the center of the block. This ice block was loaded by an in-situ hydraulic ice loading device capable of delivering approximately two million lb of load. The pressure sensor output and the test load were monitored continuously during each test so that the pressure sensor output could be compared directly to the corresponding applied pressure. The test results indicated ratios of applied ice pressure to measured sensor pressure within the range hindcast by theoretical analysis.

Development of circuit solution and design of capacitive pressure sensor array for applied robotics

2020 ◽  
Vol 8 (4) ◽  
pp. 296-307
Author(s):  
Konstantin Krestovnikov ◽  
Aleksei Erashov ◽  
Аleksandr Bykov
Keyword(s):  
Pressure Sensor ◽  
Output Signal ◽  
Sensor Array ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Fine Tuning ◽  
Capacitive Pressure Sensor ◽  
Cell Parameters ◽  
Linear Pattern ◽  
Sensor Structure

This paper presents development of pressure sensor array with capacitance-type unit sensors, with scalable number of cells. Different assemblies of unit pressure sensors and their arrays were considered, their characteristics and fabrication methods were investigated. The structure of primary pressure transducer (PPT) array was presented; its operating principle of array was illustrated, calculated reference ratios were derived. The interface circuit, allowing to transform the changes in the primary transducer capacitance into voltage level variations, was proposed. A prototype sensor was implemented; the dependency of output signal power from the applied force was empirically obtained. In the range under 30 N it exhibited a linear pattern. The sensitivity of the array cells to the applied pressure is in the range 134.56..160.35. The measured drift of the output signals from the array cells after 10,000 loading cycles was 1.39%. For developed prototype of the pressure sensor array, based on the experimental data, the average signal-to-noise ratio over the cells was calculated, and equaled 63.47 dB. The proposed prototype was fabricated of easily available materials. It is relatively inexpensive and requires no fine-tuning of each individual cell. Capacitance-type operation type, compared to piezoresistive one, ensures greater stability of the output signal. The scalability and adjustability of cell parameters are achieved with layered sensor structure. The pressure sensor array, presented in this paper, can be utilized in various robotic systems.

CMOS-MEMS Based Current Mirror MOSFET Embedded Pressure Sensor for Healthcare and Biomedical Applications

2013 ◽  
Vol 647 ◽  
pp. 315-320 ◽  
Author(s):  
Pradeep Kumar Rathore ◽  
Brishbhan Singh Panwar
Keyword(s):  
Pressure Sensor ◽  
Biomedical Applications ◽  
Circuit Simulation ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Cmos Technology ◽  
Current Mirror ◽  
Sensing Element ◽  
Pressure Sensing ◽  
Cmos Mems

This paper reports on the design and optimization of current mirror MOSFET embedded pressure sensor. A current mirror circuit with an output current of 1 mA integrated with a pressure sensing n-channel MOSFET has been designed using standard 5 µm CMOS technology. The channel region of the pressure sensing MOSFET forms the flexible diaphragm as well as the strain sensing element. The piezoresistive effect in MOSFET has been exploited for the calculation of strain induced carrier mobility variation. The output transistor of the current mirror forms the active pressure sensing MOSFET which produces a change in its drain current as a result of altered channel mobility under externally applied pressure. COMSOL Multiphysics is utilized for the simulation of pressure sensing structure and Tspice is employed to evaluate the characteristics of the current mirror pressure sensing circuit. Simulation results show that the pressure sensor has a sensitivity of 10.01 mV/MPa. The sensing structure has been optimized through simulation for enhancing the sensor sensitivity to 276.65 mV/MPa. These CMOS-MEMS based pressure sensors integrated with signal processing circuitry on the same chip can be used for healthcare and biomedical applications.

Micromachined Pressure Sensors on Optical Fiber Tip

2009 ◽  
Vol 74 ◽  
pp. 149-152
Author(s):  
X.M. Zhang ◽  
M. Yu ◽  
Silas Nesson ◽  
H. Bae ◽  
A. Christian ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Pressure Sensor ◽  
Linear Response ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Outer Diameter ◽  
Sensor Element ◽  
Batch Fabrication ◽  
In Vitro Measurements

This paper reports the development of a miniature pressure sensor on the optical fiber tip for in vitro measurements of rodent intradiscal pressure. The sensor element is biocompatible and can be fabricated by simple, batch-fabrication methods in a non-cleanroom environment with good device-to-device uniformity. The fabricated sensor element has an outer diameter of only 366 μm, which is small enough to be inserted into the rodent discs without disrupting the structure or altering the intradiscal pressures. In the calibration, the sensor element exhibits a linear response to the applied pressure over the range of 0 - 70 kPa, with a sensitivity of 0.0206 μm/kPa and a resolution of 0.17 kPa.

A pressure-deformation analytical model for rectangular diaphragm of MEMS pressure sensors

2017 ◽  
Vol 31 (05) ◽  
pp. 1750046
Author(s):  
Wu Zhou ◽  
Dong Wang ◽  
Huijun Yu ◽  
Bei Peng
Keyword(s):  
Pressure Sensor ◽  
Applied Pressure ◽  
Influence Factors ◽  
Pressure Sensors ◽  
Superposition Method ◽  
Uniform Load ◽  
Pressure Sensitive ◽  
Partial Load ◽  
Mems Pressure Sensors ◽  
Measured Pressure

Rectangular diaphragm is commonly used as a pressure sensitive component in MEMS pressure sensors. Its deformation under applied pressure directly determines the performance of micro-devices, accurately acquiring the pressure–deflection relationship, therefore, plays a significant role in pressure sensor design. This paper analyzes the deflection of an isotropic rectangular diaphragm under combined effects of loads. The model is regarded as a clamped plate with full surface uniform load and partially uniform load applied on its opposite sides. The full surface uniform load stands for the external measured pressure. The partial load is used to approximate the opposite reaction of the silicon island which is planted on the diaphragm to amplify the deformation displacement, thus to improve the sensitivity of the pressure sensor. Superposition method is proposed to calculate the diaphragm deflections. This method considers separately the actions of loads applied on the simple supported plate and moments distributed on edges. Considering the boundary condition of all edges clamped, the moments are constructed to eliminate the boundary rotations caused by lateral load. The diaphragm’s deflection is computed by superposing deflections which produced by loads applied on the simple supported plate and moments distributed on edges. This method provides higher calculation accuracy than Galerkin variational method, and it is used to analyze the influence factors of the diaphragm’s deflection, includes aspect ratio, thickness and the applied force area of the diaphragm.

scholarly journals Fabrication of Pressure Sensor Using Electrospinning Method for Robotic Tactile Sensing Application

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1320
Author(s):  
Tamil Selvan Ramadoss ◽  
Yuya Ishii ◽  
Amutha Chinnappan ◽  
Marcelo H. Ang ◽  
Seeram Ramakrishna
Keyword(s):  
Pressure Sensor ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Open Circuit ◽  
Tactile Sensing ◽  
Base Materials ◽  
Sensing Applications ◽  
Electrospinning Method ◽  
Base Polymer ◽  
External Stimuli

Tactile sensors are widely used by the robotics industries over decades to measure force or pressure produced by external stimuli. Piezoelectric-based pressure sensors have intensively been investigated as promising candidates for tactile sensing applications. In contrast, piezoelectric-based pressure sensors are expensive due to their high cost of manufacturing and expensive base materials. Recently, an effect similar to the piezoelectric effect has been identified in non-piezoelectric polymers such as poly(d,l-lactic acid (PDLLA), poly(methyl methacrylate) (PMMA) and polystyrene. Hence investigations were conducted on alternative materials to find their suitability. In this article, we used inexpensive atactic polystyrene (aPS) as the base polymer and fabricated functional fibers using an electrospinning method. Fiber morphologies were studied using a field-emission scanning electron microscope and proposed a unique pressure sensor fabrication method. A fabricated pressure sensor was subjected to different pressures and corresponding electrical and mechanical characteristics were analyzed. An open circuit voltage of 3.1 V was generated at 19.9 kPa applied pressure, followed by an integral output charge (ΔQ), which was measured to calculate the average apparent piezoelectric constant dapp and was found to be 12.9 ± 1.8 pC N−1. A fabricated pressure sensor was attached to a commercially available robotic arm to mimic the tactile sensing.

scholarly journals Modeling of a square-shape ZnO, ZnS and AlN membrane for mems capacitive pressure-sensor applications

2020 ◽  
Vol 11 ◽  
pp. 14
Author(s):  
Ahmad Dagamseh ◽  
Qais Al-Bataineh ◽  
Zaid Al-Bataineh ◽  
Nermeen S. Daoud ◽  
Ahmad Alsaad ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Pressure Sensor ◽  
Membrane Structure ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Membrane Thickness ◽  
Capacitive Pressure Sensor ◽  
The Finite Element Method ◽  
Sensor Applications ◽  
Opposite Behavior

In this paper, mathematical modeling and simulation of a MEMS-based clamped square-shape membrane for capacitive pressure sensors have been performed. Three types of membrane materials were investigated (i.e. Zinc Oxide (ZnO), Zinc Sulfide (ZnS) and Aluminum Nitride (AlN)). Various performance parameters such as capacitance changes, deflection, nonlinearity, the sensitivity of the membrane structure for different materials and film-thicknesses have been considered using the Finite Element Method (FEM) and analytically determined using the FORTRAN environment. The simulation model outperforms in terms of the effective capacitance value. The results show that the membrane deflection is linearly related to the applied pressure. The ZnS membrane provides a capacitance of 0.023 pico-Farad at 25 kPa with a 42.5% relative capacitance changes to reference capacitance. Additionally, the results show that for ZnO and AlN membranes the deflection with no thermal stress is higher than that with thermal stress. However, an opposite behavior for the ZnS membrane structure has been observed. The mechanical and capacitance sensitivities are affected by the membrane thickness as the capacitance changes are inversely proportional to the membrane thickness. Such results open possibilities to utilize various materials for pressure sensor applications by means of the capacitance-based detection technique.

Thin Film Polymer Stress Measurement Using Piezoresistive Anisotropically Etched Pressure Sensors

1995 ◽  
Vol 390 ◽  
Author(s):  
David J. Monk ◽  
Mahesh Shah
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Pressure Sensor ◽  
Stress Measurement ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Film Stress ◽  
Polymeric Coating ◽  
Stress Effect ◽  
Parylene C

ABSTRACTStresses in thin polymer films have been studied for some time by using wafer bowing, bending beams, microstructure release, and laser holographic techniques. An alternative technique for measuring stresses in thin films is discussed in the following paper. Piezoresistive anisotropically etched single crystal silicon pressure sensors are sensitive not only to applied pressure, but also to applied package stress. Deposited passivation materials, like silicone gels and polyimides, have been observed to change the sensitivity of the pressure sensor. In the current work, a thin, conformal polymeric coating (parylene C) is being developed for these pressure sensors. This thin film has been observed to reduce the sensitivity of the device as a function of the film thickness and modulus and the silicon thickness and modulus. The parylene C thin films exhibit a consistent change in film stress during annealing indicating a modification to polymer crystallinity and a corresponding change in material properties. Qualitatively, the electrical output on the pressure sensor compares favorably with measurements taken using wafer bowing. Experimental DMA and TMA work has been performed to determine the modulus (7.84 × 105 psi) and CTE (39 ppm/°C at 25 °C) of the material. However, literature values of modulus (4.1 × 105 psi) have been used with finite element analysis to model the stress effect more accurately for the thin conformal coating on the pressure sensor device. These results indicate that the sensitivity of the pressure sensor will be reduced approximately quadratically as a function of the polymer coating thickness. An empirical function has been derived to estimate sensitivity loss as a function of substrate (i.e., initial diaphragm material) modulus and thickness and coating modulus and thickness.

Ice Pressure Sensor Inclusion Factors

1981 ◽  
Vol 103 (1) ◽  
pp. 82-86 ◽  
Author(s):  
A. C. T. Chen
Keyword(s):  
Sea Ice ◽  
Pressure Distribution ◽  
Pressure Sensor ◽  
Pressure Measurement ◽  
Measurement Data ◽  
Ice Sheet ◽  
Field Tests ◽  
Approximate Equation ◽  
Analytical Work ◽  
Ice Pressure

The inclusion of a pressure sensor in an ice sheet will disturb the pressure distribution in the ice sheet. The ratio of undisturbed ice pressure to the pressure felt by the sensor, defined herein as the inclusion factor, is required in interpreting the ice pressure measurement data. An approximate equation which expresses the inclusion factor in terms of the geometry of sensor and the sea ice/pressure sensor stiffnesses ratio is proposed in this study. Some results of analytical work and field tests which were performed to evaluate the accuracy of this expression are also presented. These results demonstrate the validity of the proposed inclusion equation.

Peeling Mode Capacitive Pressure Sensor for Sub-KPA Pressure Measurements

2006 ◽  
Author(s):  
Jeahyeong Han ◽  
Shunzhou Yang ◽  
Mark A. Shannon
Keyword(s):  
Residual Stresses ◽  
Pressure Sensor ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Capacitive Pressure Sensor ◽  
Resistance To Deformation ◽  
Fixed Electrode ◽  
Electrostatic Pressure ◽  
Nonlinear Signal ◽  
Low Pressures

Capacitive pressure sensors measure changes in pressure typically by the deflection of a flexible conducting membrane towards a fixed electrode. The deflection in the membrane produces a quadratic change in capacitance, which often yields higher sensitivity to changes in pressure compared to piezo-resistive pressure sensors, which measures the resistance changes proportional to the applied pressure. However, residual stresses in the membrane can provide a substantial resistance to deformation compared to the driving force created by the applied pressure, which decreases the sensitivity at low pressures and produces a nonlinear signal. If the membrane is made compliant enough to increase sensivitiy, pull-in of the membrane can occur, reducing the effective pressure range of the capacitive manometer type pressure sensor. Hence, these type of sensors are typically not used to measure very low pressure differences over several hundred Pascals. To overcome this limitation, a capacitive pressure sensor was developed that operates in a peeling mode while under applied electrostatic actuation, which counters the residual stresses. The changes in capacitance can be detected if the pressure is just enough to overcome the interfacial electrostatic pressure. This type of pressure sensor can potentially be used for very low differential pressure differences, well below 100 Pa, over ~ 1 kPa range.

scholarly journals Fabrication and Characterization of Bending- Independent Capacitive CMOS Pressure Sensor Stacks

2018 ◽  
Vol 4 (1) ◽  
pp. 595-598
Author(s):  
Roland Fischer ◽  
Heinrich Ditler ◽  
Michael Görtz ◽  
Wilfried Mokwa
Keyword(s):  
Mechanical Stress ◽  
Pressure Sensor ◽  
Output Signal ◽  
Strong Dependence ◽  
Pressure Sensors ◽  
Target Thickness ◽  
Sensor Output ◽  
Additional Information ◽  
Four Point Bending ◽  
Foil Substrate

AbstractArtificial limbs, equipped with miniaturized tactile sensors, can handle objects with more dexterousness. Next to detecting forces, the sensor devices are also able to measure temperature. With this additional information, the touched objects can be better characterized. As such sensors, active CMOS-based capacitive pressure sensors are used in this work. The Sensors are thinned to 20-30 μm target thickness to make them bendable. One challenge of such thin sensors is the strong dependence of the output signal upon bending. To compensate this dependency, two sensors were mounted back to back. This allows a numerical adjustment of the two characteristic sensor output signals to mechanical stress curves. After electrically contacting of the stacks with a 15 μm thin polyimide foil substrate, the bending dependence of the stacks was characterized with a four-point bending procedure. By this characterization the dependency of the pressure sensor output signal on the height of mechanical stress was determined. Both sensor output signals show an inverted behavior under the same mechanical stress which confirmed prior simulation results with the same setup. Based on this information, a numerical method for compensating the bending dependence was successfully proven.

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