Touchscreen devices are found just about everywhere. Current estimates indicate that some 2.8 billion touchscreen devices will be shipped by the end of year. In comparison, only 1.3 billion were shipped in 2012. While most people know the general concept behind a touchscreen device — a device that is controlled through touch — few know the mechanics of its construction.
We’ve talked about this before on our blog, but most touchscreen devices on the market use one of two different technologies: resistive and capacitive. Resistive touchscreens register touch by pressing together two layers. When the operator touches the interface, it presses together an upper and bottom layer. The point where these layers make contact is registered as the touch. Capacitive touchscreen devices, on the other hand, register touch by identifying the electrical charge produced by the user. Touching a capacitive device sends a small electrical charge from your body to the device, which is used by the device to determine the point of contact.
Whether it’s capacitive or resistive, however, most touchscreen devices are constructed in a similar manner, typically featuring four layers. These layers consist of an upper layer coated with polyester on the top and some type of metallic conductive coating on the bottom; a “spacer” layer featuring adhesive; a glass layer featuring a top coating of transparent metallic conductive material; and a bottom adhesive layer for mounting.
The way in which a touchscreen device is constructed will directly affect its accuracy and performance. Resistive touchscreen devices, for instance, are typically less accurate than their capacitive counterpart. Identifying touch based on the operator’s own electrical charge yields greater accuracy, which is why so many smartphones and mobile handsets are capacitive and not resistive. This doesn’t necessarily mean that resistive devices are a poor choice, however. On the contrary, they offer greater resistive to dust and moisture. This benefit alone makes them an excellent choice for use in outdoor applications, as it’s able to withstand the otherwise harsh outdoor environment.
Of course, this is just one of the many ways in which touchscreen devices are constructed. Some companies may use different materials and/or techniques in their respective products. Regardless, though, the desired end result remains the same: to provide the end-user with a functional device that supports input through touch-based commands. Generally speaking, though, most touchscreen devices are constructed with four different layers. Each of these layers plays an integral part in the device’s function.