When designing a touchscreen, you have a choice between capacitive and resistive technology. Both offer advantages and limitations. We present both technologies and discuss in which situations and fields they offer you the best solution. Because the choice you make depends upon the application.
Let’s start by distinguishing between resistive and capacitive technology.
A resistive touchscreens consists of two thin layers of material with a small gap in between (spacer dots printed on one of the layers keep the layers separated). The top layer is usually a clear plastic material (such as PET-film), while the bottom layer is made up of either a second layer of plastic material or a rigid material such as glass.
Both are coated with a thin conductive layer, mostly Indium Tin Oxide (ITO). When you tap the screen, the two layers touch. A two-step process is used to measure the voltage in the X-direction and in the Y-direction. These voltages allow to determine the point of contact. The voltages are then converted into X and Y coordinates to determine the exact place of touch.
Contrary to resistive touchscreens, which rely on an electric contact by mechanical pressure, capacitive touchscreens use the natural conductivity of the human body.
Capacitive touchscreens consist also of transparent, conductive layers (usually ITO) but there is no spacer between these layers. Instead, a type of glue is used as no electrical contact is needed between the layers. The layers can be made of plastic, glass or a combination of both. Usually there is a cover glass displaying graphics or border printing.
What type of touchscreen you should go for depends on what the touchscreen will be used for. Resistive touchscreens are more common in manufacturing, medical environments and ATMs. That’s because they have a lower manufacturing cost, are more resistant to dirt and water and significantly reduce the risk of accidental touches (as pressure is needed to make the contact).
Capacitive touchscreens, on the other hand, are more frequently found in day-to-day devices such as smartphones, tablets and household appliances. The reasons for that are their increased durability, higher sensitivity to light touch (or even no touch: hovering) and the fact that they can show sharper images with better contrast (no air in the touch). Also, capacitive touchscreens will keep on working when the glass cover is cracked.
In conclusion, determining which type of touchscreen is best for your product is a matter that you should give some consideration. If you would like some more info on both technologies and how ClickTouch can help you to arrive at the best solution, don’t hesitate to get in touch with ClickTouch.