Sensitivity and packaging improvement of an LCP pressure sensor for intracranial pressure measurement via FEM simulation

A biocompatible liquid crystal polymer (LCP) pressure sensor is proposed for measuring intracranial pressure (ICP) in Traumatic Brain Injury (TBI) patients. Finite element method using COMSOL multiphysics is employed to study the mechanical behavior of the packaged LCP pressure sensor in order to optimize the sensor design. A 3D model of the 8x8x0.2 mm LCP pressure sensor is simulated to investigate the parameters that significantly influence the sensor characteristics under the uniform pressure range of 0 to 50 mmHg. The simulation results of the new design are compared to the experimental results from a previous design. The result shows that reducing the thickness of the sensing membrane can increase the sensitivity up to six times of that previously reported. An improvement of fabrication methodology is proposed to complete the LCP packaging.

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3D model of a Monolithic Honeycomb Adsorber for Electric Swing Adsorption for Carbon Dioxide Capture

JOURNAL OF ENGINEERING & PROCESSING MANAGEMENT ◽

10.7251/jepm2001001d ◽

2020 ◽

Vol 12 (1) ◽

Author(s):

Ivaná Đukic ◽

Marija Ječmenica Dučić ◽

Nikola Nikačević ◽

Menka Petkovska

Keyword(s):

Carbon Dioxide ◽

Physical Properties ◽

Power Plants ◽

3D Model ◽

Carbon Dioxide Capture ◽

Comsol Multiphysics ◽

Simulation And Optimization ◽

Electrothermal Desorption ◽

1D Model ◽

Simulation Results

The goal of this work was to develop a 3D model of Electric Swing Adsorption pro- cess for carbon dioxide capture from effluent gasses from power plants. Detailed 3D model of the composite honeycomb monolithic adsorber was developed for a sin- gle monolith channel and can be used to simulate and represent different physical properties: velocity, concentration and temperature. The advantage of this model is the fact that all physical properties and results can be presented visually in the 3D domain. COMSOL Multiphysics software was used for solving partial differential equations and simulations of adsorption and electrothermal desorption processes. Some simulation results are presented in this work. The results obtained from 3D simulations will be used for the adsorber model reduction to the 1D model which will be used for modeling and optimization of the whole ESA cycle due to its sim- plicity and computational demands. Simulation and optimization runs based on the 1D model will be performed in g-Proms software.

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Design and Simulation of Piezoresistive Pressure Sensor for Ocean Depth Measurements

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.411-414.1552 ◽

2013 ◽

Vol 411-414 ◽

pp. 1552-1558

Author(s):

Guan Rong Tang ◽

Si Di ◽

Xin Xu ◽

Qiu Lan Chen

Keyword(s):

Optimum Design ◽

Deep Water ◽

Pressure Sensor ◽

Measurement Range ◽

Comsol Multiphysics ◽

Good Linearity ◽

Piezoresistive Pressure Sensor ◽

Simulation Results ◽

Output Characteristics

This paper presents the design and simulation of a piezoresistive pressure sensor with wide operation range (up to the pressure of 1000 m-deep water). Structural and electrical simulations were carried out using COMSOL Multiphysics 4.3. The dimension of the membrane, and the geometry and placement of piezoresistors, were optimized through structural simulations. Electrical simulations were used to evaluate the performance of selected sensors. The output characteristics revealed good linearity throughout the measurement range with sensitivities of 0.4500~0.8964 mV/V/MPa. The optimum design of sensor was determined according to the simulation results.

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On the feasibility of a liquid crystal polymer pressure sensor for intracranial pressure measurement

Biomedical Engineering / Biomedizinische Technik ◽

10.1515/bmt-2018-0029 ◽

2019 ◽

Vol 64 (5) ◽

pp. 543-553

Author(s):

Preedipat Sattayasoonthorn ◽

Jackrit Suthakorn ◽

Sorayouth Chamnanvej

Keyword(s):

Liquid Crystal ◽

Intracranial Pressure ◽

Minimally Invasive ◽

Pressure Sensor ◽

Microelectromechanical Systems ◽

Liquid Crystal Polymer ◽

Monitoring Device ◽

Icp Monitoring ◽

Ongoing Research ◽

Crystal Polymer

Abstract Intracranial pressure (ICP) monitoring is crucial in determining the appropriate treatment in traumatic brain injury. Minimally invasive approaches to monitor ICP are subject to ongoing research because they are expected to reduce infections and complications associated with conventional devices. This study aims to develop a wireless ICP monitoring device that is biocompatible, miniature and implantable. Liquid crystal polymer (LCP) was selected to be the main material for the device fabrication. This study considers the design, fabrication and testing of the sensing unit of the proposed wireless ICP monitoring device. A piezoresistive pressure sensor was designed to respond to 0–50 mm Hg applied pressure and fabricated on LCP by standard microelectromechanical systems (MEMS) procedures. The fabricated LCP pressure sensor was studied in a moist environment by means of a hydrostatic pressure test. The results showed a relative change in voltage and pressure from which the sensor’s sensitivity was deduced. This was a proof-of-concept study and based on the results of this study, a number of recommendations for improving the considered sensor performance were made. The limitations are discussed, and future design modifications are proposed that should lead to a complete LCP package with an improved performance for wireless, minimally invasive ICP monitoring.

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Modeling and Simulation of MEMS based Pressure Sensor for Industrial Applications

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.h7340.119119 ◽

2019 ◽

Vol 9 (1) ◽

pp. 1739-1743

Keyword(s):

Modeling And Simulation ◽

Pressure Sensor ◽

Environmental Conditions ◽

High Sensitivity ◽

Industrial Applications ◽

Comsol Multiphysics ◽

Circular Membrane ◽

Dimensional Changes ◽

Simulation Results ◽

Input Load

This paper presents an overview of design, modeling and simulation of MEMS pressure sensor is using COMSOL Multiphysics V4.3b. An attempt has been made to achieve high sensitivity by providing different structures for membrane (Circular, square, rectangle & triangle) with uniform surface area and thickness. Further, simulations have been carried out with various loads ranging from 0.1 to 1MPa assigning three materials viz., InP, GaAs and Silicon. From the analyses of simulation results, it has been observed that the pressure sensor with circular membrane provided InP material found to exhibit more deformation and high sensitivity of 17.3×10-12 for 10 µm thickness and 50.8×10-12 for 7 µm thickness. The reasons for enhancement in the sensitivity are discussed in detail as function of input load, dimensional changes of diaphragm and materials addition. These studies are highly useful to check and compute pressure in various industrial and environmental conditions.

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Simulation and Nonlinearity Optimization of a High-Pressure Sensor

Sensors ◽

10.3390/s20164419 ◽

2020 ◽

Vol 20 (16) ◽

pp. 4419

Author(s):

Ting Li ◽

Haiping Shang ◽

Weibing Wang

Keyword(s):

High Pressure ◽

Pressure Sensor ◽

Pressure Sensors ◽

Original Model ◽

Ansys Software ◽

Nonlinear Error ◽

Sensor Model ◽

Optimized Model ◽

Simulation Results ◽

Better Than

A pressure sensor in the range of 0–120 MPa with a square diaphragm was designed and fabricated, which was isolated by the oil-filled package. The nonlinearity of the device without circuit compensation is better than 0.4%, and the accuracy is 0.43%. This sensor model was simulated by ANSYS software. Based on this model, we simulated the output voltage and nonlinearity when piezoresistors locations change. The simulation results showed that as the stress of the longitudinal resistor (RL) was increased compared to the transverse resistor (RT), the nonlinear error of the pressure sensor would first decrease to about 0 and then increase. The theoretical calculation and mathematical fitting were given to this phenomenon. Based on this discovery, a method for optimizing the nonlinearity of high-pressure sensors while ensuring the maximum sensitivity was proposed. In the simulation, the output of the optimized model had a significant improvement over the original model, and the nonlinear error significantly decreased from 0.106% to 0.0000713%.

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Fem Simulation of Micro-Rotating-Structures and Their Applications in Measurement of Residual Stresses in Thin Films

MRS Proceedings ◽

10.1557/proc-505-21 ◽

1997 ◽

Vol 505 ◽

Cited By ~ 5

Author(s):

Xin Zhang ◽

Tong-Yi Zhang ◽

Yitshak Zohar

Keyword(s):

Thin Films ◽

Residual Stresses ◽

Fem Simulation ◽

Sensitivity Factor ◽

Local Measurement ◽

Micro Structure ◽

Micro Raman Spectroscopy ◽

Before And After ◽

Polysilicon Films ◽

Simulation Results

ABSTRACTFEM simulation of micro-rotating-structures was performed for local measurement of residual stresses in thin films. A sensitivity factor is introduced, studied and tabulated from the simulation results. The residual stress can be evaluated from the rotating deflection, the lengths of rotating and fixed beams, and the sensitivity factor. The micro-structure technique was applied to measure residual stresses in both silicon nitride and polysilicon thin films, before and after rapid thermal annealing (RTA), and further confirmed by wafer curvature method. Residual stresses in polysilicon films at different RTA stages were also characterized by micro-Raman spectroscopy (MRS). The experimental results indicate that micro-rotating-structures indeed have the ability to measure spatially and locally residual stresses in MEMS thin films with appropriate sensitivities.

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Wireless Passive Intracranial Pressure Sensor Based on a Microfabricated Flexible Capacitor

IEEE Transactions on Electron Devices ◽

10.1109/ted.2018.2825247 ◽

2018 ◽

Vol 65 (6) ◽

pp. 2592-2600 ◽

Cited By ~ 2

Author(s):

Qiuxu Wei ◽

Chaochao He ◽

Jian Chen ◽

Deyong Chen ◽

Junbo Wang

Keyword(s):

Intracranial Pressure ◽

Pressure Sensor

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Video microscopy of cerebrocortical capillary flow: response to hypotension and intracranial hypertension

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1995.268.6.h2202 ◽

1995 ◽

Vol 268 (6) ◽

pp. H2202-H2210 ◽

Cited By ~ 13

Author(s):

A. G. Hudetz ◽

G. Feher ◽

C. G. Weigle ◽

D. E. Knuese ◽

J. P. Kampine

Keyword(s):

Cerebral Cortex ◽

Intracranial Pressure ◽

Flow Velocity ◽

Pressure Range ◽

Perfusion Pressure ◽

Capillary Flow ◽

Video Microscopy ◽

Cell Counting ◽

Correlation Technique ◽

Cranial Window

Although autoregulation of cerebral blood flow is well established, the response of cerebral capillary circulation to reduced cerebral perfusion pressure (CPP) is unclear. The objective of this study was to determine whether red cell flow velocity in individual capillaries of the cerebral cortex is maintained during acute decreases in CPP. Microcirculation of the superficial parietal cerebral cortex of adult barbiturate-anesthetized artificially ventilated rats was visualized using a new design of closed-perfused cranial window and epifluorescent-intensified video microscopy. Fluorescein-isothiocyanate-labeled red blood cells (FRBC) injected intravenously were used as markers of capillary flow. CPP, defined as mean arterial pressure minus intracranial pressure, was reduced by controlled hemorrhage or by stepwise elevation of local intracranial pressure. The movement of FRBC in the parenchymal capillary network was video recorded at each pressure level, and FRBC velocity in each capillary was measured off-line with use of the dual-window digital cross-correlation technique. FRBC flux in the capillaries was measured by automated cell counting. FRBC velocity at normal perfusion pressure was 1.47 +/- 0.58 (SD) mm/s and changed little in the perfusion pressure range of 70-120 mmHg. The autoregulatory index in this pressure range was 0.0049 mm.s-1.mmHg-1. Opening of previously unperfused capillaries was not observed. FRBC flux correlated with FRBC velocity, but the latter was maintained in a narrower range than FRBC flux, suggesting a decrease in capillary diameter or hematocrit with decreasing perfusion pressure. The results suggest that flow autoregulation is associated with the maintenance of capillary flow velocity and that capillary recruitment does not contribute to flow autoregulation in the rat cerebral cortex.

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