Detailed Mechanism and Engineering Applicability of Electrolytic Polymerization Aided by a Magnetic Field in Natural Rubber by Mechanical Approach for Sensing (Part 2): Other and Intrinsic Effects on MCF Rubber Property

Abstract

The same ordinary electrolytic polymerization of plastic-type polymer solution is applicable to natural rubber, with its C=C bonds, if a magnetic field and a filler are added. With the application of a magnetic field and the magnetic responsive fluid known as magnetic compound fluid (MCF), we have clarified the enhancement of the electrolytic polymerization of NR-latex and the growth of the thickness of vulcanized MCF rubber that results from the addition of a magnetic field. The present new method of MCF rubber vulcanization is effective for use in haptic sensors, which are used widely in various engineering applications. In the previous report, part 1 of this study, we investigated many experimental conditions under mechanical approach for sensing: magnetic field strength; applied voltage; electrodes gap; mass concentration, and the ingredients of the MCF. In the present sequential report, part 2, we investigate many other effects on electrolytic polymerization by the same mechanical approach for sensing as in part 1: the Mullins effect; the Piezo effect; vibration; kind of electrode; atmospheric gas. In particular, we clarify that the voltage generates spontaneously in the MCF rubber and that the MCF rubber becomes a Piezo element. These effects on the electrolytic polymerization as well as the effects of the experimental conditions will be useful in engineering applications. By taking the abovementioned parameters and effects into account, MCF rubber that is electrolytically polymerized with the aid of a magnetic field, the use of MCF as a filler, and doping, can be useful in haptic sensor applications. In particular, the effectiveness of the Piezo element can be shown.

Development of a Hybrid Piezo Natural Rubber Piezoelectricity and Piezoresistivity Sensor with Magnetic Clusters Made by Electric and Magnetic Field Assistance and Filling with Magnetic Compound Fluid

“…In the case of ①-②, by vulcanization with electric and magnetic fields, electric conductivity through the inner rubber was enhanced by electric polymerization, and the MCF rubber approached being an electric conductor, as reported in previous investigations [48,49,50]. In the case of ①-①, except for Type C, electric conductivity on the surface of MCF rubber i was no less high than that throughout the rubber in the case of ①-②.…”

“…Since the magnetic field is applied along the same direction of the electric field line, the thickness of the MCF rubber grows. If only the electric field or magnetic field is used, the electrical properties are less sensitive than when both are used, and the resulting rubber is less extensible, as shown in previous studies [48,49,50]. Therefore, both the electric and magnetic fields are necessary for larger elasticity and extensibility.…”

“…Furthermore it can be confirmed by the experiment that Types 2 and 3 has more stability than Type 1 and the cause is guessed to be due to the multilayer structure. Figure 4a is different from that of Types 1 and A in the previous study, which was conducted with an insulation paper sheet, 0.121-mm in depth and more than 100-MΩ in resistance, inserted between the MCF rubber and the upper electrode for stabilization of the induced voltage [50]. The voltage induced in the MCF rubber with doping had stable changes during the repetition, as shown in Figure 5, even if the MCF rubber did not have an insulation sheet.…”

Effect of Magnetic Field and Aggregation on Electrical Characteristics of Magnetically Responsive Suspensions for Novel Hybrid Liquid Capacitor

“…In other words, the aggregation of particles and molecules significantly affects the electric conductivity of the sensor. Our proposed sensor, which uses a magnetic compound fluid (MCF) as the magnetically responsive fluid, has the same features as these fluidic sensors [22][23][24][25][26][27][28][29][30].…”

The Effect of Particles on Electrolytically Polymerized Thin Natural MCF Rubber for Soft Sensors Installed in Artificial Skin

“…Between the MCF rubber and the acrylic resin body, a hard, non-electric body with 0.5 mm diameter was interposed, and then the rubber could be contacted exactly. This touching method was found to be more effective in a sensor, as shown in the previous study [10,11,12]. Because the contact area was smaller than the MCF rubber as a whole, and with a slight bend, the sensing then increases.…”