About the Boundary Conditions. It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric current density J equals a specific current I 0: Apr 8, 2022 · Hi, I try to model a floatting potential imposed by a 9V batterie in an specific apparatus. The Floating Potential node is used when modeling a metallic electrode at floating potential. 1 0 Replies Yu Wang Jun 25, 2010 · The final potential at this electrode can be affected by the adjacent domain (charge density, epsilon. Terminal. Note that while COMSOL employees may participate in the Electric Potential: Ground/Zero Potential: Normal Current Density: Surface Charge Density: Zero Charge: Magnetic Shielding: BH and HB curve input: Edge and Point Conditions : Edge Circuit Terminal (cylindrical electrodes) Edge Floating Potential (cylindrical electrodes) Edge Potential and Ground (cylindrical electrodes) Edge/Line and Point Oct 30, 2014 · We consider the electrostatic field computations with floating potentials in a multi-dielectric setting. For the floating potential, we assigned the boundary condition to all five of the surfaces of the contact exposed to the medium and set it to 1 mA. The Electric Potential node provides an electric potential V0 as the boundary condition V = V0. R1_i) [while calculating closed circuit voltage, I could not sure which floating potential is to connect with circuit (External I- Terminal Oct 28, 2013 · Modeling of the Electrical Double Layer (EDL) Three physics are involved in this problem: The electrostatics physics contains the equations, boundary conditions, and space charges for solving for the electric potential. Posted 02. If applied on multiple non connected boundaries, it models an electrical connection between them. in electrostatics (AC/DC module) Posted Oct 3, 2013, 5:44 a. View the specification chart to find Mar 28, 2024 · A simulation model was built in Comsol, and the surface charge density and conductor potential of the conductor was obtained under the assumption of the boundary conditions of the floating conductor; Assuming that the boundary potential of the conductor is known, the surface charge density of the conductor at different potentials is obtained Surface charge density of a floating potential electrode Posted 16 mag 2011, 13:48 GMT-4 Low-Frequency Electromagnetics Version 4. The Semiconductor Module also has the flexibility The Floating Potential subnode is available from the context menu (right-click the Single Conductor Coil parent node) or from the Physics toolbar, Attributes menu. Because the electric potential is being solved for in the physics interface, the value of the potential is typically defined at some part of the geometry. I want to use the top pzt layer and platinum electrodes as an actuator, a terminal is used to The Floating Potential node is used when modeling a metallic electrode at floating potential. AFAIK, Metal contact in Semiconductor Module (both Ohmic and Schottky), prescribes Dirichlet boundary condition for electrostatic potential. The Terminal node provides a boundary or domain condition for connection to external circuits, to transmission lines, or with a specified voltage or charge. 25 V; closed circuit Hi all, I want to drive voltage over electrode of piezoelectric in the consequences of sinusidal wave over piezo. Because the physics interface solves for A, the tangential component of the magnetic potential is always continuous, and thus the first condition is automatically fulfilled. And I wnat to read electric voltage and current from the fixed electrode placed at certain position. Electrical insulation does not impose that constraint, per se. Best regards, Jeff. The basic working principle is that a nearby magnetic field deflects the path of current through a semiconductive sensor. An electrostatic calculation always needs a ground node because even your floating potential at infinity can only be defined with reference to a fixed potential somewhere else. 3b 0 Replies Leon Rosentsvit The Floating Potential node is used when modeling a metallic electrode at floating potential. 3a, Version 4. It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric displacement field D equals a specific charge Q 0: Jul 3, 2020 · Jul 3, 2020, 5:54 a. View the specification chart to find The Floating Potential node is used when modeling a metallic electrode at floating potential. that I understand as defined by it's environment but not influencing it by removing current. COMSOL Multiphysics, which can be used to model semiconductor devices. The space charge is obtained by summing up the COMSOL version 4. The module includes features designed to model interactions of electromagnetic waves and semiconductor materials. Select a Tunnel currentItun (SI unit: A) from the list — None, User defined, or choose a tunnel current announced by one of the Insulator Tunneling features in the model. 2a, Version 4. You can even do in a transient simulation using a step function. It applies a constant voltage V0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric displacement field D equals a specific charge Q0: where Ω represents Floating Potential. Thank you sir , When adding a floating potential, the amount of charge required for a dielectric glass material depends on various factors such as the size and geometry of the glass, the desired Surface charge density of a floating potential electrode Posted 16 mai 2011, 10:48 UTC−7 Low-Frequency Electromagnetics Version 4. Piezoelectric Devices •Synthetic Jet •Inkjet Printer •Active Valves •Micro Pump •Flow Sensor •SONAR •Hydrophone •Speaker •Microphone Electron Potential Energy: Infinite Domain Modeling with Infinite Elements: Infinite Domain Modeling with Perfectly Matched Layer: Lorentz Force: Rotating Frame: Semiconductor Boundary Conditions : Surface Charge Density: Thin Insulator Gate: Continuity/Heterojunction: Continuous Quasi-Fermi Levels Model: Thermionic Emission Model: WKB Applied electric potential V 1 V Γ p + Applied electric potential V 1 V Γ n For the part of surface not covered by electrodes, Zero charge symmetry n D = 0 . Customize COMSOL Multiphysics to meet your simulation needs with application-specific modules. There are two layers in red, which are the platinum electrodes. It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric displacement field D equals a specific charge Q 0: Step 1: Magnetic Boundary Conditions. the question is what would be other electrode ? floating or terminal ? help of comsol says floating potential is a fixed potential over electrode. Considering the epsilon equal to one for your electrode is wrong !! at least the same epsilon as the adjacent domain would be more correct. With no surface currents present the physics interface conditions. Mar 8, 2017 · But in this case, the solution does not converge. The floating potential boundary condition sets the potential on the boundaries to a. Typical modeling devices are photodiodes, LEDs, and laser diodes. Using two floating potential ---one for each PZT Expression i used for open circuit voltage is abs(es. Floating Potential. The Comsol guide suggests to use Terminal for the circuit, but in this way I get 0 V in all the circuit. Up to 300 users can run up to four apps each concurrently. Shielding. Subnodes are available by clicking the parent node and selecting it from the Attributes menu. R1_v cir. R1_i) [while calculating closed circuit voltage, I could not sure which floating potential is to connect with circuit (External I- Terminal Mar 12, 2018 · Using two floating potential ---one for each PZT Expression i used for open circuit voltage is abs(es. 1 0 Replies Yu Wang Oct 3, 2013 · Floating potential b. The electric field is recovered from the gradients of the potential field ( ). 4 10 Replies May 16, 2023 · You may want to set floating potentials on your plate and cylinder -- you can find some discussions about how to do that, if you search this forum. I also see that the voltage across the electrode is constant. Also, use solid mechanics and electrostatics module to get the effect of piezoelectricity in your version of COMSOL. When the charge is set to zero, the boundary will behave as an unconnected, neutrally charged, good conductor under electrostatic conditions. The middle closed surface has an induced constant floating potential, which, due to symmetry, is the average of the potentials of the plates. Note that while COMSOL employees may participate in the May 11, 2017 · Floating Potential. It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric current density J equals a specific current I 0: Dec 3, 2018 · I calculated open circuit voltage and closed circuit voltage in two ways 1. R1_v) for closed circuit power abs(cir. It says that the integral of the current into the surface is 0 (or another user-defined value) and while this is true it doesn't seem to properly define what the boundary condition actually is used for. It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric displacement field D equals a specific charge Q 0: Sep 25, 2013 · maybe there are other ways, but what I do with success is to connect the domain to ground in. Select an External connection — None (the default) or Circuit (to connect the terminal to an electrical circuit). I notice that the boundary condition is an integral form, where the integration of the normal current density across this electrode is equated to the current applied. 2) flowing through the surface, rather than a spatially-constant current density. Posted 2 mai 2012, 16:35 UTC−4 Low-Frequency Electromagnetics, Modeling Tools & Definitions, Parameters, Variables, & Functions, Studies & Solvers Version 4. m. The modeling realization of the perfectly conducting surface is the Floating Potential boundary condition. The boundary condition also implies that the electric field lines are perpendicular to An object having charge moves, and thereby electric potential varies around the object. Using single floating potential for both PZT patch Expression i used for open circuit voltage is abs (es. Through detailed demonstrations in the software, thorough explanations, and comprehensive discussions, you will learn how to build Jul 6, 2012 · The Floating Potential node is used when modeling a metallic electrode at (a) floating potential. 4 10 Replies Academic Server License (ASL) The academic server license lets you host, manage, and run simulation applications built with the COMSOL Multiphysics ® Application Builder for use by students, faculty, and staff of your academic institution or of any other academic institution, worldwide. variable voltage. Thanks for your help. Remember that the reference potential in an electrostatic problem is an arbitrary choice. In addition, the module makes it possible to employ user-defined equations and expressions in the modeling process. In the 2D-axisymmetric model I need to have a surface with a floating-potential boundary condition and specified with the source current (total current as in v3. Example Model—Floating Potential This is a tutorial model to show how to use the floating potential and electric shielding boundary conditions in the Conductive Media DC application mode. 1. For some physics interfaces, also select additional Electric Potential nodes from the Edges (3D The Floating Potential node is used when modeling a metallic electrode at floating potential. R1_i) [while calculating closed circuit voltage, I could not sure which floating potential is to connect with circuit (External I- Terminal Jun 7, 2017 · January 10, 2022 COMSOL Employee. This means that the electric field must have no tangential component on that boundary. Floating Potentials. V0) for closed circuit voltage abs(cir. The Hall effect sensor is commonly used for position sensing. Jan 31, 2012 · Here is the situation that I need some advice on: 1. It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric displacement field D equals a specific charge Q 0: Floating Potential. As in there will be max potential at the middle instead of having the max potential at the top (floating potential node). The second condition is equivalent to the Floating Gate. Difference in potential leading to temperature difference. We placed the point current source in the center of the contact volume. The yellow layer is a pzt layer that separates platinum electrode 2 and the bottom blue pzt layer. Current injected into the gate accumulates Feb 14, 2019 · In the right image, red and blue represent a positive and negative potential, respectively. It can be used to model a boundary at a constant, unknown, coil potential. V0+es. Using "Floating potential" instead, the piezoelectric model seems to behave like a voltage source, but the circuit has no effect on it. By specifying zero charge, a floating potential condition is obtained. It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric displacement field D equals a specific charge Q 0: May 16, 2011 · Surface charge density of a floating potential electrode Posted May 16, 2011, 10:48 a. This boundary condition fixes the voltage of all of the boundaries of the sphere to a constant, but unknown, value that is computed during the solution. The top and bottom plates are held at fixed, but different, electric potentials. --. by Walter Frei. It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric current density J equals a specific current I 0: Jun 8, 2018 · When using the raised contact geometry, we evaluated each of the four source models with minor modifications. This deflection of current causes a change in potential, which can The Floating Potential node is used when modeling a metallic electrode at floating potential. Posted 22 avr. R1_vcir. 2015, 19:57 UTC+2 Low-Frequency Electromagnetics, Battery Design, Modeling Tools & Definitions, Parameters, Variables, & Functions Version 4. 119 Global Model . This 10-part, self-paced course is an introduction to modeling resistive and capacitive devices using COMSOL Multiphysics ® and the AC/DC and MEMS modules. 1 0 Replies Yu Wang Mar 13, 2021 · COMSOL version 4. A floating potential is an unknown equipotential value associated with an isolated perfect electric conductor, where the flux through the surface is zero. We start by building a model containing two capacitor plates and solving for the electrostatic field. need to be fulfilled. It applies a constant voltage V0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric displacement field D equals a specific charge Q0: where Ω represents Popular answers (1) Garsha Bahrieh. EDT. This deflection of current causes a change in potential, which can Using two floating potential ---one for each PZT Expression i used for open circuit voltage is abs(es. How do I set the floating-potential boundary Jun 28, 2019 · Now, to compare Comsol results with some published results, I want to make electrostatic potential at B to float free - in other words prescribe Neumann boundary condition for electrostatic potential. When you are introducing floating potential for a boundary condition, that boundary will be affected from the electrical Sep 2, 2016 · A floating potential boundary is also an equipotential. I'm guessing this is because the electric potential on P1 changes the floating potential which then again changes the potential on P1 and so on. R1_i) Results I have got, Open circuit voltage 43. V0) for closed circuit voltage abs (cir. PDT Low-Frequency Electromagnetics Version 4. Hi Harris, I assume that by time-dependent potential you mean that you are applying a voltage as a boundary condition of your model, and that you have a working model to simulate the stationnary conditions. It applies a constant voltage V0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric displacement field D equals a specific charge Q0: where ∂Ω represents Jun 7, 2012 · For me the name is rather explicit, the first definiton I get from the help: The Floating Potential node is used when modeling a metallic electrode at (a) floating potential. again I want to drive varing potential relative to caring frequency over piezoelectric Apr 12, 2022 · The attached pdf is the layer structure. Then I can change the resistance from 0 (=grounded) to. c. Nov 9, 2015 · Hello Ari, There is a floating potential boundary condition available right out of the box in the AC/DC Module's and the MEMS Module's electrostatic physics interface. It includes a dedicated physics interface to model semiconductor devices with the drift-diffusion equations , enhanced capabilities for modeling electrostatics, and an Example Model—Floating Potential This is a tutorial model to show how to use the floating potential and electric shielding boundary conditions in the Conductive Media DC application mode. 2012, 16:35 GMT-4 Low-Frequency Electromagnetics, Modeling Tools & Definitions, Parameters, Variables, & Functions, Studies & Solvers Version 4. Mar 11, 2021 · How to Model a Hall Effect Sensor with COMSOL Multiphysics®. It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric current density J equals a specific current I 0: The Floating Potential node is used when modeling a metallic electrode at floating potential. R1_v) for closed circuit power abs (cir. 3, Version 4. It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric displacement field D equals a specific charge Q 0: Difference in temperature of a material leading to potential difference which is also known as Seebeck effect. I have set a fixed potential on the test electrode (left circle), -1V. The charge which will be generated in the piezoelectric device, can be collected Sep 25, 2015 · Magnus. Jul 9, 2015 · I am using the floating potential to represent the current injection through a highly conductive electrode. fp2. Introduction to Modeling Resistive and Capacitive Devices. It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric displacement field D equals a specific charge Q 0: The Floating Potential node is used when modeling a metallic electrode at floating potential. Γ f For floating electrodes electrically not connected floating potential satisfying n J 0. However, if it is your intention to prepare an electrostatic model an electric conductor that is immersed in an insulating medium (such as May 4, 2016 · In order to understand weak constraints (to be used in a more complicated problem), I am trying to reproduce a 'Floating Potential' node (in electrostatics) by weak constraints. fp1. The Floating Potential node is used when modeling a metallic electrode at (a) floating potential. I'm a bit confused about the description of the Floating Potential boundary condition in the Electric Currents mode. So we need boundary condition (terminal or floating potential) for electrode, and it is coupled to electric circuit physics. I have also tried to first run the simulation using a floating potential and recorded the resulting instrument potential V_ins. Is this due to how potential is calculated in comsol? Thanks. So, I have to set up the model with more generality instead of using "Laplace Equation (lpeq)". Good luck. Posted 22 apr 2015, 13:57 GMT-4 Low-Frequency Electromagnetics, Battery Design, Modeling Tools & Definitions, Parameters, Variables, & Functions Version 4. I have two concentric electrodes - one at an arbitrary voltage and one earthed. The floating potentials can be integrated into the formulations directly or can be approximated by a dielectric medium with high Feb 1, 2012 · I am fairly new to COMSOL and was wondering of anyone knows how to correctly define a floating electrode in a 2D simulation? I have some strange results from my simulation. I've tried many solutions but it does not work and did not find anything in model example. Thanks a lot for your quick reply. . Middle East Technical University. 4 floating potential boundary condition missing. Electron Potential Energy: Infinite Domain Modeling with Infinite Elements: Infinite Domain Modeling with Perfectly Matched Layer: Lorentz Force: Rotating Frame: Semiconductor Boundary Conditions : Surface Charge Density: Thin Insulator Gate: Continuity/Heterojunction: Continuous Quasi-Fermi Levels Model: Thermionic Emission Model: WKB The Floating Potential node is used when modeling a metallic electrode at floating potential. In that case, in the field where you normally set the applied voltage, simply write whatever time-dependent In Part 3 of this 10-part course on modeling resistive and capacitive devices, we begin our discussion on and demonstrations of modeling capacitors and looking at the electric fields and capacitance of a system. The application lies as electric generator. Floating Potentials and Electric. This model is targeted to model Seebeck effect and works as a thermoelectric generator. The charge which will be generated in the piezoelectric device, can be collected into the floating potential electrode. The Floating Potential boundary condition will make the potential constant over the assigned boundaries and the resulting potential will depend on the integral current source, "I0", specified (default: I0=0). 2 13 Replies Dec 15, 2010 · I don't know if it's better to couple the physics with a "Terminal" BC or "Floating potential". It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric current density J equals a specific current I 0: In general, to add a node, go to the Physics toolbar, no matter what operating system you are using. it is clear that one electrode to be grounded. . The Terminal node also enables the computation of the lumped parameters of the system, such as capacitance. The value of this voltage is set so that the integral of the current. It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric displacement field D equals a specific charge Q 0: 6 | CONTENTS Limitations of the Heavy Species Transport Equations. 05. Sep 25, 2015 · I'm a bit confused about the description of the Floating Potential boundary condition in the Electric Currents mode. an external circuit with an resistor. March 11, 2021. Apr 1, 2014 · However, the potential distribution in the surface plot is not a smooth gradient along the whole curved surface. Requires MEMS Module or, alternatively, AC/DC Module + any of Acoustics Module or Structural Mechanics Module. The application lies in cooling purpose. ) and of course by the floating potential that you assumed. density normal to the boundary is equal to the source current that you have specified: May 2, 2012 · May 11, 2017, 1:51 a. Dec 20, 2018 · On the other hand, to model a transducer as a receiver only, a Floating Potential feature can be used as well. The analysis includes solving the same model changing between the two different boundary conditions and with and without weak constraints on the boundaries. To go systematically, I did the following in the attached model: CASE 1: Electric Potential. Between them is an insulation layer with an embedded cylindrical electrode at floating potential. The effect is indeed also that the tangential electric field and tangential current density will become zero so for clarity it Floating Potential. The floating voltage is applied between two electrodes but this specific voltage must not be referenced to the general ground in the model. It applies a constant voltage V 0 on the boundary (for domain features, this is the boundary enclosing the selected domain), such that the total normal electric displacement field D equals a specific charge Q 0: Mar 11, 2021 · How to Model a Hall Effect Sensor with COMSOL Multiphysics®. They have one pzt layer in blue between them. Requires the AC/DC Module and one of the Structural Mechanics Module, MEMS Module, or Acoustics Module. 2 13 Replies The Floating Potential node is used when modeling a metallic electrode at floating potential. The exterior and interior boundary conditions listed in Table 4-1 are available. a very big value (= inf = floating). where n is unit vector normal to the surface and D is the electric displacement vector. da ff km hc lq yr kz km gz iw