What is the basic difference between Inductive and capacitive touch screen?

Question

I have seen Smartphones mentioning of two terms frequently; naming Inductive touch and Capacitive touch screen. What is their basic difference and what is the advantage of one over another?

Answer 1

It's just the method they use to detect the touch. In capacitive touch they lay down a grid of Indium Tin Oxide (ITO) and connect it to some sensors. Then when your finger which comes either in contact or really close the capacitance of the circuit changes and a touch is detected.

For inductive I've seen two kinds, one that's pen based where there are a bunch of elements putting out a small EM field. Then in the pen there is some circuitry that resonantes and sends back a signal to the pad or tablet screen.

In the phone case it's probably the newer approach of having an element that creates and senses it's own small magnetic field. Then when the user touches the glass or overlay it deflects slightly which modifies that magnetic field. Thus sensing the touch.

Capacitive has the downside of if it gets wet it can't accurately detect where the touch is because the water is affecting the capacitance. Also if you try to use it with a glove or stick it won't work because it won't change the capacitance enough.

Inductive won't have that problem but whatever material you use will have to deflect a little or use some stylus. I don't know as much about inductive though. Maybe this method also requires more power to maintain the EM field?

Answer 2

I have seen inductive sensing systems offered by Microchip.

They consist of a PCB trace coil covered by a metal plate or dome. When the plate is pushed towards the coil, it causes a slight change in the inductance of the coil which can be measured.

Answer 3

in capacitive touch they sense heat .if our finger touchs the capacitive touch pad then it performs in contrary inductive touch pad is not heat sensing pad so by your finger nails or through some sticks it performs or move.