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How to model change in capacitance of capacitive sensor to human finger touch

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Hi All,
I am designing a capacitive sensor model based on electrostatic comb drive model. I have attached a copy of my model with this post for reference. I want to know the impact on capacitance(i.e. change in capacitance) of the attached sensor when human body comes into contact with the sensor. To model touch by human body(i.e. human finger), I have placed a dielectric slab of 500um thickness on top of PMMA insulator(please see the model for clear understanding) with dielectric constant of 50(I found this value on internet for <1Ghz AC signal). Is there any material inside material browser that is close to human tissue? Please let me know. Since human body is connected to ground, I have to model the dielectric slab with ground connection. Can you suggest me whats the better way to model human body(with ground connection) touching the capacitive sensor. From comsol simulation I need to measure the change in capacitance with and without touch of human finger. Any help is appreciated.
Best Regards
Kiran

2 Replies Last Post 5 mar 2012, 18:12 GMT-5

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Posted: 1 decade ago 5 mar 2012, 18:09 GMT-5

Hi All,
I am designing a capacitive sensor model based on electrostatic comb drive model. I have attached a copy of my model with this post for reference. I want to know the impact on capacitance(i.e. change in capacitance) of the attached sensor when human body comes into contact with the sensor. To model touch by human body(i.e. human finger), I have placed a dielectric slab of 500um thickness on top of PMMA insulator(please see the model for clear understanding) with dielectric constant of 50(I found this value on internet for <1Ghz AC signal). Is there any material inside material browser that is close to human tissue? Please let me know. Since human body is connected to ground, I have to model the dielectric slab with ground connection. Can you suggest me whats the better way to model human body(with ground connection) touching the capacitive sensor. From comsol simulation I need to measure the change in capacitance with and without touch of human finger. Any help is appreciated.
Best Regards
Kiran

Hi
I am not able to attach the model. It says file extension error when attaching my .mph model

[QUOTE] Hi All, I am designing a capacitive sensor model based on electrostatic comb drive model. I have attached a copy of my model with this post for reference. I want to know the impact on capacitance(i.e. change in capacitance) of the attached sensor when human body comes into contact with the sensor. To model touch by human body(i.e. human finger), I have placed a dielectric slab of 500um thickness on top of PMMA insulator(please see the model for clear understanding) with dielectric constant of 50(I found this value on internet for

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Posted: 1 decade ago 5 mar 2012, 18:12 GMT-5

I have attached the model in the below link

www.comsol.com/community/exchange/196/

I have attached the model in the below link http://www.comsol.com/community/exchange/196/

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