Development of coil winding process for radial gap type electromagnetic micro-rotating machine

Abstract

This paper presents a manufacturing process for forming the coil winding on a cylindrical core to make a stator for a micro-generator. A cylindrical stator 1 mm in diameter and 0.5 mm in length was fabricated. This stator consists of a cylindrical core made of permalloy and six coils of copper wire with a cross section of 7 M m X 15 ,U m which were wound 20 turns per coil and with 2 pm thick polyimide insulation layers. The stator was fabricated by securing the coil onto the core die, and electroplating the remaining area with permalloy. A micro-generator 1.2 mm in diameter was fabricated incorporating this stator, and the voltage induced by the generator was measured. The examination revealed that the newly developed process is applicable to the manufacture of electromagnetic microdevices.