If you keep up with our blog here at Nelson-Miller, you probably know that there are two primary touchscreen technologies: capacitive and resistive. From smartphones and tablet computers to human machine interfaces (HMIs) and smart appliances, countless touchscreen panels are powered by either capacitive or resistive touch-sensing technology. They’ve been around for decades, and while other touch-sensing technologies have since emerged, capacitive and resistive remain the industry standard.
Capacitive touchscreen devices live up to their namesake by measuring capacitance. When you touch the display, your finger will absorb some of the capacitive device’s electrical field, allowing it to determine where exactly you touched. This principle sounds simple enough. But how do resistive touchscreen devices? Because they don’t measure or otherwise look for changes in capacitance, resistive touchscreen devices feature a completely different method of function.
The Basics of Resistive Touch-Sensing Technology
Resistive touchscreen devices don’t use changes in capacitive to identify touch commands. Rather, they rely on pressure. When you touch the display, you’ll force an upper and bottom layer to make contact. The precise location where these two layers touch is essentially the same location as your touch command, thereby allowing the device to identify your touch.
How Resistive Touchscreen Devices Are Manufactured
Different companies manufacture their resistive touchscreen devices in different ways. Most, however, design them with an upper layer of a hard coating material, followed by a top sheet layer with ITO underneath. Underneath this top sheet layer is a separate “middle” layer of air or inert gas. And below this middle layer is a bottom sheet layer with the same ITO. Now, if you press down on the display, you’ll force the ITO on the two respective layers to make contact. And because ITO is highly conductive, it allows the device to determine your precise point of contact.
Of course, there are pros and cons to using resistive touchscreen technology. On the plus side, you can use them with a bare finger, gloved finger or a stylus — something that can’t be said for capacitive touchscreen devices. Resistive touchscreen devices also boast a high resolution, allowing for crystal-clear, detailed images. On the other hand, they also have a shorter lifespan than capacitive touchscreen devices. Another potential disadvantage of resistive touchscreen technology is that it’s less responsive to light-pressure touches. This isn’t a huge issue, though. It just means that you need to press down harder using your finger or a stylus in order for the device to register your touch command.