Implementation of inductive proximity sensor using nanoporous anodic aluminum oxide layer

This study presents an inductive proximity sensor implemented through the integration of nano-texture metal-spiral and np-AAO (anodic aluminum oxide (AAO) with nanopores) insulation layer on Si-substrate. The advantages of such nano-structure inductive proximity sensor are as follows, (1) The surface area of nano-texture metal-spiral is increased. Thus, the performance of inductive sensor is increased; and (2) The nano-texture metal-spiral consists of nanopores transferred from the AAO template. Thus, the eddy current on metal-spiral induced by lower electrode can be reduced by the nanoporous film. In applications, inductive proximity sensor consisted of nano-texture Au-spiral on np-AAO is implemented. Measurements demonstrate the performance of the nano-texture proximity sensor is significantly improved.