Magnetic Nanofiber Mats for Data Storage and Transfer

Abstract

Electrospun nanofiber mats may serve as new hardware for neuromorphic computing. To enable data storage and transfer in them, they should be magnetic, possibly electrically conductive and able to respond to further external impulses. Here we report on creating magnetic nanofiber mats, consisting of magnetically doped polymer nanofibers for data transfer and polymer beads containing larger amounts of magnetic nanoparticles for storage purposes. Using magnetite and iron nickel oxide nanoparticles, a broad range of doping ratios could be electrospun with a needleless technique, resulting in magnetic nanofiber mats with varying morphologies and different amounts of magnetically doped beads.

Magnetic Properties of Electrospun Magnetic Nanofiber Mats after Stabilization and Carbonization

“…Both materials are ferrimagnetic in bulk form and become superparamagnetic for very small nanoparticles [65,66]. The polymer: nanoparticle weight ratio used here was 1:1.8, identical to the highest nanoparticle concentration used in a previous study [18].…”

“…Figure 2 depicts SEM images of the magnetite samples under examination; Figure 3 shows SEM images of the nickel-ferrite samples. As mentioned in Section 2, magnetic nanofiber mats with beads along the fibers were produced to test the combination of structures for data storage and transport for possible application in neuromorphic computing [18]. It should be mentioned that the aim of our recent study was not optimization of the numbers and dimensions of the beads, but investigation of the magnetic properties of nanofiber mats directly The simulated hysteresis loops shown here were superposed of 7 hysteresis loops each, simulated for external magnetic field sweeps in the range of ±3000 Oe with the field axis applied along 0 • (horizontal in Figure 1), 15 • , .…”

“…Figure 3 shows SEM images of the nickel-ferrite samples. As mentioned in Section 2, magnetic nanofiber mats with beads along the fibers were produced to test the combination of structures for data storage and transport for possible application in neuromorphic computing [18]. The simulated hysteresis loops shown here were superposed of 7 hysteresis loops each, simulated for external magnetic field sweeps in the range of ±3000 Oe with the field axis applied along 0° (horizontal in Figure 1), 15°, … 90° (vertical in Figure 1).…”

“…Here, instead, we report on a combination of magnetic nanofibers with beads, tailored by a reduction of the polymer content in the spinning solution, as evaluated in detail in a former study [59]. This combination of long, thin nanofibers with beads along the fibers allows for combining data processing and storage, as shown in former studies [18,[60][61][62][63].…”

“…These can be used in diverse applications such as filters [7][8][9], biotechnology and tissue engineering [10][11][12], for energy harvesting and storage [13,14], or other "smart" functions [15]. Recently, a strong focus of diverse research groups has been related to electrospinning magnetic nanofibers, either as composites [16][17][18] or, after calcination of the composites to remove polymers, as pure metal nanofibers [19][20][21]. Such magnetic nanofiber mats can be used, e.g., as catalysts [22], for magnetic hyperthermia [23], or electromagnetic shielding [24].…”