Technology Resources

How do Touchscreens work?

Touch Screens
Touchscreens are a common feature of our daily lives. We use them on devices like smartphones, ATM displays, and car consoles. The number of devices that use touchscreens is growing quickly, and the technology is expanding to meet the growing need. Right now, we see two types of touchscreens most often in our devices: Capacitive and resistive touch. They both use electric fields to identify when a finger or a stylus touches the screen. They have different characteristics and uses, and those are summarized below:

Capacitive touch

  • Capacitive touch uses the electrical capacity of the human body to identify where a touch occurs on a screen. When a finger or other conductive material touches the screen’s surface, it disrupts the electric field at that point, which identifies the user’s selection.
  • It is the technology most commonly used in consumer electronics like tablets, smartphones, and gaming devices.
  • It has a high degree of accuracy, so it is good for smaller devices or applications where the touch area to select is small.
  • It can sense multiple simultaneous touch points, which are used for making multiple selections at once or for navigation. An example is when two points are touched and then pinched together to make the image smaller.

Resistive touch

  • Resistive touchscreens have two layers with a gap between them, with the top layer being semi-flexible. Each layer has an electric grid and a resistive coating on the surface, preventing the two grids from making an electrical connection until pressure is applied to the top layer. When something presses the top layer, the electrical circuit is closed, identifying the location of the user’s selection.
  • Resistive touchscreens can work with devices that aren’t conductive and are more reliable in conditions where debris or fluids might get on their surface.
  • They are less expensive than capacitive touchscreens, which makes them popular in rugged or high-use settings. You see resistive touch used most often for factory automation, devices in construction, medical equipment,  and in-flight entertainment stations.