Characterization and actuation of a magnetic photosensitive polymer cantilever

Magnetic polymer microactuators made of SU-8 and superparamagnetic nanoparticles are reported. Homogenous distribution of nanoparticles in the composite was obtained using superparamagnetic nanoparticles and a surfactant. The magnetic polymer composite (MPC) was micromachined into cantilevers using photolithography. The magnetic characterization of the MPC was performed by a superconducting quantum interference device (SQUID). An electromagnet applied magnetic forces to this composite. The force per volume of composite was determined experimentally by measuring the force on a film of MPC using a micro-force sensor. The cantilevers were excited with an AC electromagnet at different frequencies, and their resonance modes were captured by a laser-Doppler vibrometer. Deflections were increased about 10 times by the addition of a DC field. The tip deflection amplitude of a cantilever (160 mum times 1.65 mum) in resonance was found to be 63 nm at 15.78 kHz.