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Q & A: no-hands ipod screen

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Most recent answer: 08/23/2013
Q:
Hi thank you for your great knowledge. Question: I would like to control my IPad touch screen without touching it. A stylus pen is a conduit for the bodies electric field. I want to create the bodies electric field mechanically with no human connection. Is that possible and what would it take? IE: batteries, chip?
- scott (age 45)
haverhill ma
A:

ipods use capacitative touch screens. I don't believe these use the capacitance of your body to ground. Rather, they use changes in the capacitance between little parts of a circuit in the screen. These capcitors are sensitive to any dielectric or conductor that enters their field lines. 

Ordinary touch-screen styli work by mechanical contact with little resistive switches in a different type of touch screen. They use styli that typically don't have conducting tips or even ones with much of a dielectric coefficient. Those won't work on an ipad. Nevertheless, you don't need to use your finger. You can get styli with conducting  tips for use with an ipad. They don't need any electrical connection to you.

Mike W.


(published on 08/23/2013)

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