The touchpad sensor is a four-wire resistive type, composed of two resistive layers separated by an air gap. One plate is used for the X-axis and the other is used for the Y-axis. When pressure is applied, the two resistive plates make contact. A microcontroller measures this position and pressure then uses advanced, proprietary algorithms to yield smooth mouse functionality. On this slide figure 1 shows the electrical representation of the sensor. Figure 2 shows a simplified exploded view of the sensor.