Fabrication and characterization of 3D micro-coils with hybrid manufacturing methods

This study presents novel fabrication steps and hybrid approaches that combine contemporary methods with modified manufacturing strategies for fabricating 3D micro-coils on tubular surfaces. Although several methods have been developed in the last decade, most of them still rely on complicated multi-step lithography processes or sophisticated devices. In this article, rapid, simple, and straightforward approaches are presented for fabricating micro-coils directly on curved surfaces. The hybrid fabrication methods in this study provide an alternative solution to reduce the complexity in fabrication steps, provide better control over aspect ratios and the homogeneity of thin film coatings on tubular surfaces. Micro-coils from copper and conductive polymer with outer diameter of 2.5 mm and line width of 40 μm and a separation of 110 μm were designed, produced, and characterized. Magnetic fields inside the coils made of copper and conductive polymer were measured as 11 and 2.5 μT, respectively. The developed coating and structuring methods will open new avenues not only in application fields such as analytical characterization methods of fluidic samples with miniaturized nuclear magnetic resonance (μNMR) systems, but also for 3D sensor fabrication on curved surfaces.