A computer keyboard has a grid of conductors forming a plurality of intersections, with force-sensitive resistor (FSR) elements located between the conductors at the intersections. A plurality of keys are located above the intersections and exert force on the conductors and FSR elements during key presses....http://www.google.de/patents/US7256768?utm_source=gb-gplus-sharePatent US7256768 - Computer keyboard with quantitatively force-sensing keys
