View Single Post
Feb29-12, 04:10 PM
P: 2
I've been playing around with projected capacitive touchscreens - specifically, the iPhone's. I've attached a white paper that outlines the details, but the basic idea is as follows:
An iPhone's touchscreen has a dielectric layer sandwiched between a layer of conductors arranged in rows and a layer of conductors arranged in columns. The result is a grid of capacitors that can be independently driven. When a finger (or anything capable of sapping enough charge) comes close enough to these pseudo-capacitors, the field between them is altered, and a touch is registered. ("Close enough" has been tuned to exactly the point at which a finger touches the iPhone's glass screen.)

What I'm wondering is - is it possible to alter these fields in the same way, but from further away than originally intended? Perhaps with a generated E-field? In general, can you alter the mutual capacitance of two conductors with an external field?

Thanks in advance!
Phys.Org News Partner Physics news on
Mapping the optimal route between two quantum states
Spin-based electronics: New material successfully tested
Verifying the future of quantum computing