Magnetoresistive micro-displacement sensor based on magnetorheological fluid

摘要

A novel magnetoresistance material based on magnetorheological fluid (MRF) was developed for applications in micro-displacement sensor. The MRF samples were fabricated by dispersing carbonyl iron particles (CIP) into a magnetic ion liquid (MIL) composed of 1-methylethyl ether-3-butylimidazole cation and [Fe2Cl7](-) anions. The magnetoresistance characteristics were also systematically tested. It was found that the resistance value of MRF with a CIP content of 20 vol% decreased from 125 to 24.4 K omega when increasing the magnetic field from 0 to 0.2 T. A sensor device was developed to study the displacement sensing characteristics of MRF, and found that the sensor had a high sensitivity of 0.1 omega mu m(-1) and a high resolution of 10.0 mu m. The excellent performance can be attributed to the low modulus and good stability of the MIL matrix, allowing for easy change of the resistance by controlling the magnetic field or displacement. In summary, these unique characters make the present MRF a promising magnetoresistance material with potential applications in displacement sensor.