scholarly journals Modeling, Simulation and Performance Analysis of Multichannel Mems Piezoelectric Cantilevers for Cochlear Implantable Module

2021 ◽  
Vol 11 (2) ◽  
pp. 510-530
Author(s):  
J. Abdul Aziz Khan ◽  
P. Shanmugaraja ◽  
S. Kannan
Keyword(s):  
Von Mises Stress ◽  
Frequency Range ◽  
Piezoelectric Cantilever ◽  
Audible Frequency ◽  
And Performance ◽  
Piezoelectric Cantilevers ◽  
Von Mises ◽  
Implantable Sensor ◽  
Complete Frequency ◽  
The Brain

This work presents the enhanced area-efficient Multi-channel MEMS (Micro-Electrical Mechanical System) piezoelectric cantilever device (PCD) for a fully cochlear implantable sensor that works within the audible frequency range of 300-4800 Hz. The sound pressure level (SPL) of 95 dB, 100 dB, and 110 dB input is given in order to resonates the audible frequency range of the device which is placed on the eardrum. This stimulates the auditory nerve via the cochlea to send information to the brain. As a result, the Multi-channel MEMS piezoelectric cantilever device generates the highest potential voltage of 870 mV at 110-dB SPL and is detected under the excitation of 300 Hz. The output parameters such as von Mises stress, displacement, and the complete frequency bandwidth performance are analyzed using COMSOL Multiphysics.

scholarly journals SIMULATION AND ANALYSIS OF DIFFERENT PIEZOELECTRIC MATERIALS IN MEMS CANTILEVER FOR ENERGY HARVESTING

2021 ◽  
Vol 9 (1) ◽  
pp. 1321-1328
Author(s):  
Abdul Aziz Khan J , Shanmugaraja P , Kannan S
Keyword(s):  
Energy Harvesting ◽  
Lead Zirconate Titanate ◽  
Piezoelectric Materials ◽  
Low Frequency ◽  
Lead Zirconate ◽  
Vital Role ◽  
Von Mises Stress ◽  
And Performance ◽  
Von Mises ◽  
Implantable Sensor

MEMS Energy Harvesting(EH) devices are excepted to grow in the upcoming years, due to the increasing aspects of MEMS EH devices in vast applications. In Recent advancements in energy harvesting (EH) technologies wireless sensor devices play a vital role to extend their lifetime readily available in natural resources. In this paper the design of MEMS Cantilever at low frequency (100Hz) with different piezoelectric materials Gallium Arsenide (GaAs), Lead Zirconate Titanate (PZT-8), Tellurium Dioxide (TeO2), Zinc oxide (ZnO) is simulated and performance with different materials are compared. The results are analyzed with various parameters such as electric potential voltage, von mises stress, displacement. The paper discusses the suitability of the piezoelectric material for MEMS fully cochlear implantable sensor application.

scholarly journals Mechanical Strength Study of a Cranial Implant Using Computational Tools

2022 ◽  
Vol 12 (2) ◽  
pp. 878
Author(s):  
Pedro O. Santos ◽  
Gustavo P. Carmo ◽  
Ricardo J. Alves de Sousa ◽  
Fábio A. O. Fernandes ◽  
Mariusz Ptak
Keyword(s):  
Structural Integrity ◽  
Mechanical Performance ◽  
Skull Fracture ◽  
Human Head ◽  
Element Model ◽  
Von Mises Stress ◽  
Cranial Implant ◽  
Von Mises ◽  
Two Parameters ◽  
The Brain

The human head is sometimes subjected to impact loads that lead to skull fracture or other injuries that require the removal of part of the skull, which is called craniectomy. Consequently, the removed portion is replaced using autologous bone or alloplastic material. The aim of this work is to develop a cranial implant to fulfil a defect created on the skull and then study its mechanical performance by integrating it on a human head finite element model. The material chosen for the implant was PEEK, a thermoplastic polymer that has been recently used in cranioplasty. A6 numerical model head coupled with an implant was subjected to analysis to evaluate two parameters: the number of fixation screws that enhance the performance and ensure the structural integrity of the implant, and the implant’s capacity to protect the brain compared to the integral skull. The main findings point to the fact that, among all tested configurations of screws, the model with eight screws presents better performance when considering the von Mises stress field and the displacement field on the interface between the implant and the skull. Additionally, under the specific analyzed conditions, it is observable that the model with the implant offers more efficient brain protection when compared with the model with the integral skull.

Simulation of Brain Response to Noncontact Impacts Using Coupled Eulerian–Lagrangian Method

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Miao Na ◽  
Timothy J. Beavers ◽  
Abhijit Chandra ◽  
Sarah A. Bentil
Keyword(s):  
Brain Tissue ◽  
Mechanical Response ◽  
Brain Regions ◽  
Von Mises Stress ◽  
Fe Model ◽  
Brain Response ◽  
Fe Method ◽  
Angular Velocities ◽  
Von Mises ◽  
The Brain

Abstract Finite element (FE) method has been widely used for gaining insights into the mechanical response of brain tissue during impacts. In this study, a coupled Eulerian−Lagrangian (CEL) formulation is implemented in impact simulations of a head system to overcome the mesh distortion difficulties due to large deformation in the cerebrospinal fluid (CSF) region and provide a biofidelic model of the interaction between the brain and skull. The head system used in our FE model is constructed from the transverse section of the human brain, with CSF modeled by Eulerian elements. Spring connectors are applied to represent the pia-arachnoid connection between the brain and skull. Validations of the CEL formulation and the FE model are performed using the experimental results. The dynamic response of brain tissue under noncontact impacts and the brain regions susceptible to injury are evaluated based on the intracranial pressure (ICP), maximum principal strain (MPS), and von Mises stress. While tracking the critical MPS location on the brain, higher likelihood of contrecoup injury than coup injury is found when sudden brain−skull motion takes place. The accumulation effect of CSF in the ventricle system, under large relative brain−skull motion, is also identified. The FE results show that adding relative angular velocities, to the translational impact model, not only causes a diffuse high strain area, but also cause the temporal lobes to be susceptible to cerebral contusions since the protecting CSF is prone to be squeezed away at the temporal sites due to the head rotations.

Bridging Finite Element and Machine Learning Modeling: Stress Prediction of Arterial Walls in Atherosclerosis

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Ali Madani ◽  
Ahmed Bakhaty ◽  
Jiwon Kim ◽  
Yara Mubarak ◽  
Mohammad R. K. Mofrad
Keyword(s):  
Machine Learning ◽  
Neural Networks ◽  
Finite Element ◽  
Deep Neural Networks ◽  
Prediction Models ◽  
Plaque Rupture ◽  
Training Data ◽  
Von Mises Stress ◽  
And Performance ◽  
Von Mises

Finite element and machine learning modeling are two predictive paradigms that have rarely been bridged. In this study, we develop a parametric model to generate arterial geometries and accumulate a database of 12,172 2D finite element simulations modeling the hyperelastic behavior and resulting stress distribution. The arterial wall composition mimics vessels in atherosclerosis–a complex cardiovascular disease and one of the leading causes of death globally. We formulate the training data to predict the maximum von Mises stress, which could indicate risk of plaque rupture. Trained deep learning models are able to accurately predict the max von Mises stress within 9.86% error on a held-out test set. The deep neural networks outperform alternative prediction models and performance scales with amount of training data. Lastly, we examine the importance of contributing features on stress value and location prediction to gain intuitions on the underlying process. Moreover, deep neural networks can capture the functional mapping described by the finite element method, which has far-reaching implications for real-time and multiscale prediction tasks in biomechanics.

scholarly journals Development of a Finite Element Head Model for the Study of Impact Head Injury

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Bin Yang ◽  
Kwong-Ming Tse ◽  
Ning Chen ◽  
Long-Bin Tan ◽  
Qing-Qian Zheng ◽  
...  
Keyword(s):  
Finite Element ◽  
Brain Injuries ◽  
Current Knowledge ◽  
Human Head ◽  
Von Mises Stress ◽  
Head Model ◽  
Fe Model ◽  
Prediction And Prevention ◽  
Von Mises ◽  
The Brain

This study is aimed at developing a high quality, validated finite element (FE) human head model for traumatic brain injuries (TBI) prediction and prevention during vehicle collisions. The geometry of the FE model was based on computed tomography (CT) and magnetic resonance imaging (MRI) scans of a volunteer close to the anthropometry of a 50th percentile male. The material and structural properties were selected based on a synthesis of current knowledge of the constitutive models for each tissue. The cerebrospinal fluid (CSF) was simulated explicitly as a hydrostatic fluid by using a surface-based fluid modeling method. The model was validated in the loading condition observed in frontal impact vehicle collision. These validations include the intracranial pressure (ICP), brain motion, impact force and intracranial acceleration response, maximum von Mises stress in the brain, and maximum principal stress in the skull. Overall results obtained in the validation indicated improved biofidelity relative to previous FE models, and the change in the maximum von Mises in the brain is mainly caused by the improvement of the CSF simulation. The model may be used for improving the current injury criteria of the brain and anthropometric test devices.

Structure Design and Simulation Analysis of Multiple Micro Piezoelectric Cantilevers

2013 ◽  
Vol 562-565 ◽  
pp. 1208-1213
Author(s):  
An Ran Jiang ◽  
Shi Qiao Gao ◽  
Feng Lin Yao ◽  
Yun Li He
Keyword(s):  
Resonant Frequency ◽  
Structural Design ◽  
Simulation Analysis ◽  
Structure Design ◽  
The Finite Element Method ◽  
Frequency Range ◽  
Piezoelectric Cantilever ◽  
Generation Capacity ◽  
Cantilever Array ◽  
Piezoelectric Cantilevers

In order to effectively capture the environment vibration energy, convert it into electricity and supply energy for the microelectronics devices, multiple micro piezoelectric cantilevers are designed. It is composed of more than one piezoelectric cantilever array, which broaden the resonant frequency band of the piezoelectric vibrator, and it can produce resonance or similar to the resonance in a frequency range. Compared to a single piezoelectric cantilever, multiple piezoelectric cantilevers can effectively broaden the resonant frequency and improve the piezoelectric power generation capacity. The simulation results show that the finite element method can provide important theoretical guidance for the structural design of multiple micro piezoelectric cantilevers.

Simulation of Mouse Brain Tissue Under Controlled Cortical Impact

2018 ◽  
Author(s):  
Haifeng Zhao ◽  
Changxin Lai ◽  
Ke Wang ◽  
Suhao Qiu ◽  
Tianyao Wang ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Mouse Brain ◽  
Impact Angle ◽  
Von Mises Stress ◽  
Fe Model ◽  
Controlled Cortical Impact ◽  
Cortical Impact ◽  
Von Mises ◽  
The Impact ◽  
The Brain

Traumatic brain injury is one of the leading causes of injury and death in both developed and developing countries. Animal models are important preclinical tools for injury level studies. In this study, a finite element (FE) model of mouse brain was constructed to investigate the biomechanical responses of brain tissue during a controlled cortical impact (CCI). Impact of the brain tissue was simulated with varying impact speeds and angles. Computational results indicated that the viscoelastic properties of the brain tissue and the impact angle could greatly influence the injury responses. Comparison with the experimental observation showed that energy based stress parameters such as the von Mises stress has the potential to be descriptive of the injury levels.

Effects of occlusal scheme on All-on-Four abutments, screws and prostheses: A three-dimensional finite element study

2020 ◽  
Author(s):  
Nurullah Türker ◽  
Hümeyra Tercanlı Alkış ◽  
Steven J Sadowsky ◽  
Ulviye Şebnem Büyükkaplan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Good Prognosis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Group Function ◽  
Occlusal Contact ◽  
Maximum Deformation ◽  
Contact Points ◽  
Von Mises

An ideal occlusal scheme plays an important role in a good prognosis of All-on-Four applications, as it does for other implant therapies, due to the potential impact of occlusal loads on implant prosthetic components. The aim of the present three-dimensional (3D) finite element analysis (FEA) study was to investigate the stresses on abutments, screws and prostheses that are generated by occlusal loads via different occlusal schemes in the All-on-Four concept. Three-dimensional models of the maxilla, mandible, implants, implant substructures and prostheses were designed according to the All-on-Four concept. Forces were applied from the occlusal contact points formed in maximum intercuspation and eccentric movements in canine guidance occlusion (CGO), group function occlusion (GFO) and lingualized occlusion (LO). The von Mises stress values for abutment and screws and deformation values for prostheses were obtained and results were evaluated comparatively. It was observed that the stresses on screws and abutments were more evenly distributed in GFO. Maximum deformation values for prosthesis were observed in the CFO model for lateral movement both in the maxilla and mandible. Within the limits of the present study, GFO may be suggested to reduce stresses on screws, abutments and prostheses in the All-on-Four concept.

The Influence of Loading Position in A Priori High Stress Detection using Mode Superposition

2020 ◽  
Vol 1 (1) ◽  
pp. 93-102
Author(s):  
Carsten Strzalka ◽  
◽  
Manfred Zehn ◽  
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
A Priori ◽  
High Stress ◽  
Von Mises Stress ◽  
Detailed Knowledge ◽  
Variable Loading ◽  
Numerical Effort ◽  
Von Mises

For the analysis of structural components, the finite element method (FEM) has become the most widely applied tool for numerical stress- and subsequent durability analyses. In industrial application advanced FE-models result in high numbers of degrees of freedom, making dynamic analyses time-consuming and expensive. As detailed finite element models are necessary for accurate stress results, the resulting data and connected numerical effort from dynamic stress analysis can be high. For the reduction of that effort, sophisticated methods have been developed to limit numerical calculations and processing of data to only small fractions of the global model. Therefore, detailed knowledge of the position of a component’s highly stressed areas is of great advantage for any present or subsequent analysis steps. In this paper an efficient method for the a priori detection of highly stressed areas of force-excited components is presented, based on modal stress superposition. As the component’s dynamic response and corresponding stress is always a function of its excitation, special attention is paid to the influence of the loading position. Based on the frequency domain solution of the modally decoupled equations of motion, a coefficient for a priori weighted superposition of modal von Mises stress fields is developed and validated on a simply supported cantilever beam structure with variable loading positions. The proposed approach is then applied to a simplified industrial model of a twist beam rear axle.

scholarly journals Numerical Investigation of the Deformable Porous Media Treated by the Intermittent Microwave

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 757
Author(s):  
Tianyi Su ◽  
Wenqing Zhang ◽  
Zhijun Zhang ◽  
Xiaowei Wang ◽  
Shiwei Zhang
Keyword(s):  
Porous Media ◽  
Heat Transport ◽  
Liquid Water ◽  
Von Mises Stress ◽  
Temperature Deformation ◽  
Local Maxima ◽  
Whole Process ◽  
Surface Areas ◽  
Pulse Ratio ◽  
Von Mises

A 2D axi-symmetric theoretical model of dielectric porous media in intermittent microwave (IMW) thermal process was developed, and the electromagnetic energy, multiphase transport, phase change, large deformation, and glass transition were taken into consideration. From the simulation results, the mass was mainly carried by the liquid water, and the heat was mainly carried by liquid water and solid. The diffusion was the dominant mechanism of the mass transport during the whole process, whereas for the heat transport, the convection dominated the heat transport near the surface areas during the heating stage. The von Mises stress reached local maxima at different locations at different stages, and all were lower than the fracture stress. A material treated by a longer intermittent cycle length with the same pulse ratio (PR) tended to trigger the phenomena of overheat and fracture due to the more intense fluctuation of moisture content, temperature, deformation, and von Mises stress. The model can be extended to simulate the intermittent radio frequency (IRF) process on the basis of which one can select a suitable energy source for a specific process.

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