Why Does Water Confuse My Touch Screen?

The power of a drop of water and your fingertip.
Karin Heineman, ISTV Executive Producer

(Inside Science TV) -- It’s no secret that water and electronics don’t mix. If you drop your cell phone in a puddle, you’re likely to have to pay several hundred bucks or more in order to repair the damage. But have you ever noticed that the tiniest bit of sweat or just one raindrop makes your touchscreen go bonkers? Why is that?  

Touch screen technology may seem like magic but what is really happening is called capacitive technology. When a finger touches the screen a tiny electrical charge is transferred to the finger and completes the circuit, this creates an electrical change at that point on the screen signaling the software to make the action happen such as like typing, or opening an app.

The problem is that water may also conduct electricity just like your finger. Even small amounts of moisture, such as a drop of sweat or rain, may provide another channel for the electricity.

Capacitive touchscreens may view excess moisture, or a drop of water, the same way it does a finger touch. Causing the screen to register a "touch" wherever moisture is present.

This isn’t a huge issue, but it’s still enough to affect the overall performance of a touchscreen device.

There’s a solution but it’s relatively new called self-capacitance. It’s technology that makes it so touchscreens don’t register moisture as touch -- problem solved.


Author Bio & Story Archive

Karin Heineman is the executive producer of Inside Science TV.