From NUI Group Community Wiki
Multi-touch (or multitouch) denotes a set of interaction techniques which allow computer users to control graphical applications with several fingers. Multi-touch consists of a touch screen (e.g., computer display, table, wall) or touchpad, as well as software that recognizes multiple simultaneous touch points, as opposed to the standard touchscreen (e.g. computer touchpad, ATM), which recognizes only one touch point.
Frequently used optical methods
- Frustrated Total Internal Reflection (FTIR)
- Diffused Illumination (DI)
- Diffused Surface Illumination (DSI)
- Laser Light Plane (LLP)
Optical sensors integrated into an LCD panel
Planar Systems' Active Matrix LCD with integrated Optical Touchscreen uses optical sensors interspersed among LCD pixels to sense touch.
Capacitive touch screen
The iPhone uses a capacitive method acquired from Fingerworks. This method can be costly for the hobbyist or self-builder due to the complex electronic grid needed. See: justDIY Capacitive Touch Sensing
For a larger list see the Multitouch Technologies section.