There are a number of different ways to go about making a do-it-yourself (DIY) touch screen, and each one can be best suited to a particular application. In order to turn a regular netbook or laptop into a touch screen computer, the easiest method typically involves the application of a transparent capacitive or resistive sensor layer. If a DIY touch screen needs to work with a stylus, then a resistive touch screen is the way to go, otherwise capacitive typically provides better results. Another low cost option for building a DIY touch screen is known as frustrated total internal reflection (FTIR), which uses an acrylic sheet and a number of light emitting diodes (LEDs) to create a multitouch surface that can be placed over a display.
Touch screens are a class of input devices that allow a person's finger or a stylus to interact with a computer. These screens are built into many smartphones, and other portable computing devices, though most desktop monitors, laptops and netbooks lack this input method. It is possible to add a DIY touch screen to anything from a netbook computer to a large television though, and a number of methods can be uased.
The simplest way to make a DIY touch screen is to use a commercial sensor layer. These sensors are clear, can be laid out over an existing monitor or screen, and typically have adhesive on one side. The best type of sensor layer to use can depend on the application, though capacitive screens are typically easier to view in bright light, and are often capable of multi-touch. A resistive sensor should be chosen in cases where a stylus needs to be used, since capacitive touch screens can only be activated by a fingertip. It is also important to choose a touch sensor that is the same size as the screen that is being modified, and to carefully place it in the correct position.
Another low cost alternative when building a DIY touch screen is referred to as frustrated total internal reflection. This method uses a sheet of clear acrylic that is placed over a television screen or monitor, in addition to a video camera and an array of infrared LEDs. These touch screens are well suited to many commercial applications since they can be virtually any size, can stand up to a lot of pressure without damaging the monitor, and are capable of sensing multiple touches at a time. This is due to the fact that the reflection pattern of the LEDs within the acrylic sheet is interfered with whenever something touches the screen, which can be recorded by the video camera and then processed into input data by a computer.
