Preliminary Study on the Feasibility of Using Permanent Magnetic Elastomer as a Stretchable Skin Sensor

Sensor technology will greatly accelerate the development of automation, especially in the field of robotics, particularly for safe interaction with both humans and the environment. In previous work, permanent magnet elastomers (PMEs), which were produced by mixing Neodymium powders into a silicone base and subsequently magnetizing the material, were integrated in skin sensors, and force detection experiments based on magnetic field changes were performed. This study investigates the changes in magnetic fields of PMEs made from silicone bases of various softness when stretched, as well as performs cyclic tests to analyze the elongation of each PME sample. The experimental results show that a linear relationship exists between the magnetic field of PMEs and the stretched distance, which was evaluated using a linear fit with a slope in the range of -0.006 to -0.057 mT/mm. Moreover, the findings demonstrate that the PMEs can be used to measure pressing forces even when they are being stretched. The elongation of PME changes by 4% for sample made from Dragon Skin™ 10 MEDIUM (D10) and 1.4% for sample made from Ecoflex™ 00–50 (E50). The results confirmed the feasibility of using PMEs as stretchable sensors.