Minput

Minput is a sensing and input method that enables intuitive and accurate interaction on very small devices ones too small for practical touch screen use and with limited space to accommodate physical buttons.

It has two, inexpensive and high-precision optical sensors (like those found in optical mice) to the underside of the device. This allows the entire device to be used as an input mechanism, instead of the screen, avoiding occlusion by fingers.

In addition to x/y translation, it also captures twisting motion, enabling many interesting interaction opportunities typically found in larger and far more complex systems.