How TouchScreen Works? Simple Technology Explanation!!

Touchscreens are one of the coolest technology which have has revolutionized the world. The first touchscreen was introduced by the founder of Apple INC Steve Jobs. 

Touchscreens are everywhere, in your mobile phones, restaurants, airplanes, subways and even in bathrooms nowadays. Have you ever by mistake given a thought on how these touchscreen actually work? What is the process behind it and how can screen just change when tapping on it? Continue reading the article to get the answers of all such type of questions related to the touchscreen


Taking about the old and early touchscreen, in order to make them work you have to press hard on  the screen in order to make it work but the new generation and modern touchscreen are so fast that they just work on our little tap or touch of the finger

Touchscreen is of old generation or new, both of them work on the same fundamental principle in order to make it a successful touch. Every touchscreen has goal to send the precise electrical signal from point where screen has been touched.

Resistive Touchscreens

 The most common and widely used touchscreen are Resistive Touchscreens. In these type of touchscreen user has to tap hard and press inside the screen in order to make it work.

Resistive touchscreens have two layers. Top Layer is made of a flexible transparent material, commonly known as plastic, an example of such type of plastic can be soda bottles or Coca- cola bottles and bottom layer is made of a hard thing, which is mostly glass.



 Between the top and the bottom layer we have a very thin layer of metal compound which would allow the electrical signals to pass. Mostly this metal compound is indium tin oxide due to its transparent properties. On the middle layer, we also have spacer made up of an insulating material through which electrical signals cannot pass and are divided over the middle the layer in order to prevent the false touch, refer to the image for more clearity.


When the screen is ON, a voltage follows across the screen in both horizontal and vertical directions. Whenever we touch the screen from top layer which is flexible, voltage across the screen changes, a small processor can identify the exact coordinate where the screen has been touched.


These touchscreens have a very long life due to their reliability and durability, which means they wont break easily. These type of touchscreens are mostly used in restaurants, airports, metro stations etc.

 Using these type of touchscreens can be really frustrating and tiring at times, because if we didn’t press quite hard then the touchscreen won’t work or respond to the user command. These type of touchscreens cannot understand multiple touches such as two finger zoom in and zoom out etc.
Prevent these type of problems and make touchscreen more advance we have capacitive touchscreens, which are explained below.


Capacitive touchscreens

 These are the modern type of touchscreen and of the very simple example can be your own phone. In capacitive touchscreens our finger plays a very main role and not surprisingly are part of the touchscreen itself.

The basic capacitive touchscreen has a glass sheet having thin grid lines.  On this glass sheet, driving lines are flowing in one direction through which current is flowing and sensing lines in the other direction in order to detect the electric current

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The points where the driving liens and sensing lines are crossing, an electrostatic field is formed, which is registered by the processor of the smartphone. These changes can only take place whenever a conductive material touches the screen. Whichever point we touch the screen, on that point charge gets concentrated, disturbing the flow of electrostatic field. This allows electrostatic field to  know about the charge. 
Green Dot - Charge stored when touched
Yellow dot- electrostatic field

Electrostatic Field getting Disturbed 

The processor with capacitive touchscreens are really powerful and can detect very small changes in the electrostatic field such as a simple tap, scrolling up and down and multiple touches can also identified. Small touches can be detected due to the very thin grid line on the screen which allows to make the touch accurate.

If you will touch the screen with an insulating material such as rubber or nail, the touchscreen won’t response as now charge is gathered and no disturbance in the electrostatic field.
Now whenever you are touching the screen remember that you are part of the system, don’t think that the electricity is flowing through your fingers.