We have an application where a small conductive piece is placed on skin. This conductive object then moves a tiny amount (around 0.4mm) away from the sensing electrode, and we would need to measure the displacement. The diameter of the conductive object is about 2mm and the sensing distance around 1 mm.
Because human is a pretty good conductor, we need to develop a system where the capacitive effects of the person are filtered out. Also because the distance between the sensing electrode and ground electrode can vary, we have been considering some form of ratiometric measurement.
Our first idea is to measure the distance with one sensor electrode, which is placed just above the conductive target. We would have another electrode just outside the conductive target, and this would measure the capacitance of the person as well as potential displacement of the reader device.
Are there any methods of achieving this with FDC2214 and could this be tested with the FDC2214EVM?
