One of the foremost challenges of position sensing is to achieve high resolution and accuracy over a large range. For example, semiconductor wafer stages require a repeatability and resolution in the nanometers while operating over a range in the tens of centimeters [13,14]. Such applications typically use interferometers or high resolution optical encoders which can provide the required performance but can impose a significant cost. Long range sensors are also becoming necessary in standard nanopositioning applications due to the development of dual-stage actuators [77–80] and
stepping mechanisms [81,82]. Capacitive sensors can be adapted for this purpose by using a periodic array of electrodes [55]. Such techniques can also be applied to magnetic or inductive sensing principles. Due to the increasing availability of long range nanopositioning mechanisms, an increased focus on the development of cost effective long range sensors is required.