An area-change sensing through capacitive techniques is disclosed. In one
embodiment, a first conductive surface is substantially parallel to a
second conductive surface. The first conductive surface may be moveable
relative to the second conductive surface in a direction substantially
parallel to the second conductive surface. A processing module may detect
an overlap area between the first conductive surface and the second
conductive surface. In addition, a reference surface may be substantially
parallel to the first conductive surface and the second conductive
surface. The processing module may be configured to measure a reference
capacitance between the reference surface and a selected surface of the
first conductive surface and the second conductive surface. The
processing module may apply an algorithm that considers the reference
capacitance and converts a change in capacitance between the first
conductive surface and the second conductive surface to at least one of a
voltage response and a frequency response to determine the measurement.