Modulus-tunable magnetorheological elastomer microcantilevers

• Published in: Smart materials and structures Vol. 23; no. 5; pp. 55017 - 6
• Main Authors: Lee, Dongkyu, Lee, Moonchan, Jung, Namchul, Yun, Minhyuk, Lee, Jungchul, Thundat, Thomas, Jeon, Sangmin
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.05.2014; Institute of Physics
• Subjects: Anisotropy; Damping; Decay; Deflection; Dissipation; Elastomers; Exact sciences and technology; General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Iron; Magnetic fields; magnetorheological elastomer; Mechanical instruments, equipment and techniques; microcantilever; Micromechanical devices and systems; Physics; sensor; Transducers; Damping; Dimethylsiloxane polymer; Electromagnetic actuators; Deflection; Magnetorheological elastomer; Magnetic field effects; Microminiaturization; Cantilever beam; Magnetic particles; Magnetic sensors; Anisotropy; Resonance frequency; Dissipation; Microelectromechanical device
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/0964-1726/23/5/055017

Modulus-tunable microcantilevers are fabricated from magnetorheological elastomers (MREs) consisting of polydimethylsiloxane and carbonyl iron particles by using a simple sandwich molding method. Depending on the presence or absence of an external magnetic field during curing, isotropic or anisotropic MRE cantilevers are obtained. Randomly distributed particles are present in the polymer matrix of the isotropic microcantilevers, whereas the particles in the anisotropic microcantilevers are aligned in the direction of the magnetic field. The fractional changes in the resonance frequencies of the MRE cantilevers are measured as functions of the magnetic field intensity and the quantity of particles in the matrix. The anisotropic microcantilevers undergo greater changes in frequency than the isotropic microcantilevers when exposed to external magnetic fields, which indicates that larger changes in modulus are induced in the anisotropic microcantilevers. In addition, the dissipation and damping ratios of the MRE microcantilevers are determined by fitting the exponential decays of their deflection amplitudes with time.