Friday, 7 February 2020

electric fields - What physical properties of materials trigger the capacitive touch screen?


I have watched some youtube videos about capacitive touch screen


http://www.youtube.com/watch?v=ZHzaVzYEZbw


http://www.youtube.com/watch?v=GmCE18RMEeQ


The videos show that a conductor(finger), in which charges can be induced, can be used to trigger the capacitive touch screen. However, I tried to wear a plastic glove to hold a metal rod to touch the screen and no detection is triggered.


I really want to know the physics theory about the capacitive sensing.


Can someone tell me what physical properties or shape trigger the capacitive touch screen?


Is there any examples that something WITHOUT conducting to human body can trigger the screen?


(P.S. I have read other posts about capacitive touch screen here and do not find a good answer so this is not a duplicate)




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