Magnetometamaterials: Metamaterials with Tunable Magnetic Matter Conductivity

The transport of tiny particles is of great interest in the field of lab-on-a-chip. Here, by drawing inspiration from electric materials, we introduce magnetometamaterials, which, as opposed to electrons, transport magnetic particles (i.e., matter). The proposed metamaterial is composed of lithographically patterned disk-shaped micromagnets arranged in rows forming linear magnetic tracks on a silicon substrate. It is shown that by applying an external rotating magnetic field with the right frequency, the particles move along the magnetic tracks. The magnetic matter transport rate (i.e., magnetic matter conductivity) is tuned by adjusting the external magnetic field. We show that the particle transport is similar to the classical electron transport through a periodic lattice. At low frequencies, similar to the electrons at low temperatures, the particles move in closed loops around single magnets, resulting in an insulating regime. At higher frequencies, similar to the electrons at higher temperatures, some particles show the same behavior (i.e., move in closed loops); however, some others move along the magnetic tracks (i.e., demonstrate open trajectories). This behavior resembles a magnetic matter semiconductor. At even higher frequencies, all the particles show open trajectories along the magnetic tracks, and the device resembles a magnetic matter conductor. We define the operational ranges, both theoretically and experimentally, for both one- and two-dimensional magnetometamaterials. We show that, in an appropriate vertical bias field, the two-dimensional magnetometamaterials can transport the particles in arbitrary paths. The proposed metamaterial in this work can be used in designing circuits for transporting particles with crucial applications in biomedical engineering.

Automated summary

Magnetometamaterials, inspired by electric materials, can transport magnetic particles and their transport behavior is similar to electron transport in periodic lattices. The transport rate of magnetic particles can be tuned by adjusting the external magnetic field. Two-dimensional magnetometamaterials can transport particles in arbitrary paths under appropriate conditions.