PCB Coil Pairs for Small Magnetic Volumes

Area of Science:

• Electrical Engineering
• Biomedical Engineering
• Materials Science

Background:

• Localized radiofrequency (RF) magnetic fields are crucial for applications like magnetic nanoparticle heating and actuation.
• Conventional solenoidal systems often present limitations in terms of size, sample volume, and power consumption.

Purpose of the Study:

• To describe a novel, compact RF magnetic field generator.
• To enable field generation within millimeter-scale volumes.
• To assess its suitability for applications requiring localized magnetic fields.

Main Methods:

• Design and fabrication of a compact RF magnetic field generator using stacked, paired parallel printed multilayer circuit board (PCB) coils.
• Characterization of RF response, including impedance and scattering parameters.
• Electromagnetic modeling and experimental measurement of magnetic field amplitude and spatial homogeneity.

Main Results:

• The PCB-based coil configuration significantly reduces device size, sample volume, and power requirements compared to solenoidal systems.
• The system operates effectively near ~330 kHz, a frequency relevant for magnetic nanoparticle heating.
• Electromagnetic modeling showed a maximum local deviation from the mean field of 5.5%.
• Experimental measurements confirmed a mean B_z field of 6.3 ± 0.1 mT/A between paired PCBs.

Conclusions:

• The developed compact RF magnetic field generator is a viable alternative to conventional systems for localized field generation.
• The device's performance characteristics are consistent with the requirements for magnetic nanoparticle heating applications.
• This PCB-based coil design offers a scalable and efficient solution for micro-scale magnetic field applications.