Manipulation of the electromagnetic near‐fields by 3D printed coils: from design to fabrication

Abstract

Nowadays, the advancements in three‐dimensional (3D) printing technology have made it possible for sophisticated structures to be fabricated fast, accurate, and affordable. In this study, a new method is proposed for the manipulation of near‐electric and magnetic fields based on 3D coils. The manipulation of near‐fields is widely used in various electromagnetic problems. The 3D coils lead to 3D distributions of current paths. By changing the shape of the coil (i.e. the current path) the desired electric field or magnetic field can be achieved. During the design procedure, at first dyadic Green's functions are used to calculate the electric and magnetic fields. Also, proper basis functions are used to define the current paths. Following that, with the help of genetic algorithm, the coefficients of the basis functions, and thus the shape of 3D coils are derived for the realisation of the desired field. Finally, this method is used to realise a normal distribution on a curved path. The coils are fabricated with fused deposition modeling (FDM) 3D printing technology and by attaching the conductive wires to the printed structure. The results of design, numerical simulations, and experimental tests indicate the high performance of this technique for manipulation of near‐electric and magnetic fields.

Single-Sided Near-Field Wireless Power Transfer by A Three-Dimensional Coil Array

“…To this aim, the spatial forming of subwavelength magnetic fields is a potential solution and may enable the control of the produced magnetic field and the formation of a single-sided radiation pattern aimed only at the Rx coils and away from the lossy media [12,27,28,29]. A traditional method to focus the magnetic field and suppress its leakage has been introduced by Halbach [30], which has since been the basis of a multitude of biomedical treatments such as magnetic drug delivery [31,32,33].…”

Control of near electric field by topology optimised sub‐wavelength 3D loop antenna

“…At low frequencies (kHz and lower), these types of antennas are often called coils. Coils have many uses, including magnetic drug delivery and wireless power transfer [5,6]. Many of these applications require a specific near or far fields' distribution.…”