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COMSOL is not considering the relative permittivity
Posted 2025/05/18 21:18 GMT-4 MEMS & Piezoelectric Devices Version 6.3 4 Replies
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I am using the guide for capacitors and resistors and i can see that COMSOL is not taking the proper values. If I manually multiply the equation while plotting it matches to what graphs i should get and if I place a dielectric in some other medium there is no variation in field or potential
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Hello Vikash,
You may be considering one of those (many) situations where some of the fields are independent of some of the material properties. See this old thread for a discussion of that.
Best,
Jeff
-------------------Jeff Hiller
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i am trying to find the electric potential and capacitance, should it not depend on the material and the video i followed (https://www.comsol.com/support/learning-center/article/introduction-to-modeling-resistive-and-capacitive-devices-27591/132) had different results with different materials, i tried multiple time to make sure i followed all the steps. The results from the video and mine varied in the way that if nylon had been used i would get a value of capacitance 4 times lesser, which is the relative permittivity of nylon
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Hello Vikash,
As of more recent versions of the software (since those tutorials were published) the Electrostatics interface now has a "Free Space" feature that imposes unit permittivity on all domains. Override this with the "Charge Conservation in Solids" feature.
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I am able to do now thank you for your help, the series is also very helpful.