Fabrication and surface characterization of photopatterned encapsulated micromagnets for microrobotics and microfluidics applications

In this paper, encapsulated micromagnets with magnetic core surrounded by pure SU-8 were fabricated utilizing multilayer photolithography with a middle NdFeB magnetic composite layer. Various geometries of micromagnets were fabricated with high density magnetic core and high resolution features, showing magnetically response while still being biocompatible and chemically resistant and making them suitable for a wide range of microrobotics and microfluidics applications. Especially, crescent and C-channel micromagnets showed potential of microtransportation devices because of their interior reservoirs. Surface characterization of the micromagnets was conducted using closed-form solutions derived from the general biplanar surface characterization method. The fabrication method was evaluated and the process errors were found less than 1%.