Low-Cost Production of Biocompatible Single-Sized Micron-sized Iron Particles in Microfluidic Channels under Strong Magnetic Field

Traditionally, kilogram-scale iron (and its alloys) particles can be synthesized by atomizing molten iron. These atomized particles typically follow a log-normal distribution, with a particle size distribution (PSD) usually ranging from a few microns to hundreds of microns. In other words, there is a wide distribution of particle size. In this study, we propose a separation method by passing a solution containing magnetic particles through microfluidic channel within a strong magnetic field. Due to the different magnetic drag forces for different Fe particle sizes, micron-sized Fe particles with almost a single diameter can be separated. This method allows low-cost production of biocompatible single-sized iron particles that can be used as the inner core of core-shell magnetic particles for various applications such as: biofunctionalized colloidal coating for biosensing, biology, and medicine applications. Previous reports from our group showed iron particles by conventional sieving methods in the size range of 1-7 μm [1,2]. The validation experimental setup used in this study included a syringe pμmp, a microfluidic micro-fluidic channel, and a digital microscope [2]. The solution is extruded from the syringe through the syringe pμmp, flows through the catheter to the microfluidic channel on top of a magnetic source. A digital microscope is used to record images on the specific XZ plane from the Y-axis. Through experimental studies, optimized parameters including PSD variation, solution viscosity, separation efficiency, magnetic field intensity and distribution, etc. are reported. Preliminary in vivo biocompatibility testing results of these iron particles will also be reported.