Magneto-Dielectric Effects in Polyurethane Sponge Modified with Carbonyl Iron for Applications in Low-Cost Magnetic Sensors

Abstract

In this study, magnetizable polyurethane sponges (MSs) were obtained from commercial absorbent polyurethane sponges (PSs) doped with carbonyl iron microparticles (CIPs). Based on MSs, we manufactured cylindrical capacitors (CCs). The CCs were subjected to both a magnetic field and an alternating electric field, with a frequency of f=1 kHz. Using an RLC bridge, we measured the series electric capacitance, Cs, and the tangent of the loss angle, Ds. From the functions Cs=CsδCCs and Ds=DsδCCs, we extracted the components of the complex dielectric permittivity. It was found that the CIPs embedded in the MS matrix aggregated, leading to magneto-dielectric effects such as the enhancement of the complex dielectric permittivity components when applying the magnetic field as a principal effect and the enhancement of the electric capacitance and time constant of the capacitors as a secondary effect. The obtained results represent landmarks in the realization of low-cost magnetic field sensors, deformation and mechanical stress transducers in the robotics industry, etc.

Magneto-Tactile Sensor Based on a Commercial Polyurethane Sponge

“…It was a piezoresistive sensor with a sensitivity of 166 mV/m, which was able to detect forces with values up to 3 N and had applications in making prostheses or robots with a precise grip and an intelligent control of objects touched. The development of electrical devices whose response functions are sensitized by the use of an external magnetic field was reported in [42][43][44][45]. In [42,43], the fabrication of mechanical deformation sensors using cotton fiber fabrics with iron carbonyl microparticles and barium titanate nanoparticles was reported.…”

Electrorheological and magnetorheological properties of liquid composites based on polypyrrole nanotubes/magnetite nanoparticles

“…On the practical front, the potential applications of these composites are diverse and impactful. They include the development of biomedical devices [30], the creation of controllable mechanical shock and vibration dampers [31][32][33], and the advancement in electromagnetic wave absorbers and sensors tailored for electric and magnetic fields [34]. This exploration not only contributes to our understanding of the material science behind PPyM-based LC but also opens up new avenues for their application in various technological fields.…”

Composite Materials Based on Polymeric Fibers Doped with Magnetic Nanoparticles: Synthesis, Properties and Applications

“…The electrical devices made with these composites can be useful in recording the limits allowed by the labor protection rules for magnetic and electric fields. In commercial sponges, carbonyl iron microparticles attach electrostatically to polyurethane fibers, forming a magnetizable composite [24]. Inserted between copper cylindrical electrodes, they form a capacitor.…”

“…Inserted between copper cylindrical electrodes, they form a capacitor. Using the planar capacitor method [25], the authors of the paper [24] obtain information on the modification of the dispersion coefficients and of the energy absorption of a mediumfrequency electromagnetic field, and respectively when applying a static magnetic field. The composite obtained in Ref.…”

“…The composite obtained in Ref. [24] is low-cost and useful for the absorption of medium frequency electromagnetic radiation. The electrical device based on this composite stands out as an excellent electromagnetic radiation sensor.…”