Magneto-Tactile Sensor Based on a Commercial Polyurethane Sponge

Abstract

In this paper, we present the procedure for fabricating a new magneto-tactile sensor (MTS) based on a low-cost commercial polyurethane sponge, including the experimental test configuration, the experimental process, and a description of the mechanisms that lead to obtaining the MTS and its characteristics. It is shown that by using a polyurethane sponge, microparticles of carbonyl iron, ethanol, and copper foil with electroconductive adhesive, we can obtain a high-performance and low-cost MTS. With the experimental assembly described in this paper, the variation in time of the electrical capacity of the MTS was measured in the presence of a deforming force field, a magnetic field, and a magnetic field superimposed over a deformation field. It is shown that, by using an external magnetic field, the sensitivity of the MTS can be increased. Using the magnetic dipole model and linear elasticity approximation, the qualitative mechanisms leading to the reported results are described in detail.

A Cotton Fabric Composite with Light Mineral Oil and Magnetite Nanoparticles: Effects of a Magnetic Field and Uniform Compressions on Electrical Conductivity

“…Similar effects are described in [ 20 , 35 ], where the fabrication of composites based on polymers and CI microparticles is reported. In [ 20 ], a composite was made based on natural polymers, and in [ 35 ], one based on a synthetic polymer was created. In both cases, the electrical conductivity was electronic.…”

“…By applying a magnetic field, magneto-elastic deformations were generated in the composites, which reduced the contact distance between the conductive microparticles. This resulted in an increase in the electrical conductivity of the composite with an increase in the B values of the magnetic flux density [ 20 ] and, respectively, of the contact pressure, as reported in [ 35 ]. Compared to the MCs created in the present work, in previous studies, CI microparticles were not sufficiently stable on the polymer microfibers.…”

Composites Based on Cotton Microfibers Impregnated with Magnetic Liquid for Magneto-Tactile Sensors

“…Similar effects are reported in Refs. [54,55] and it can be observed from the above equations for the equivalent electrical capacitance and resistance. These also show that fixed values of B and Φ Fe 3 O 4 , the values of A ε and A σ increase linearly with F, as seen from Figures 10b and 10c, and Figures 12b and 12c, respectively.…”

“…It is known that in a gravitational field, and respectively by application of a uniform field of compression forces, the distance between magnetizable particles decreases [54,55]. The net effect is the increase of the equivalent electrical capacitance, and respectively a decrease of the equivalent electrical resistance of ED with increasing the compression forces.…”