Development of a cantilever-type ferro-actuator using a porous PVDF membrane

Abstract

In this study, we propose a cantilever-type ferro-actuator using porous polyvinylidene fluoride (PVDF) membrane. Generally, a ferro-actuator is fabricated by the absorption of ferro-fluid on a backbone membrane containing strongly magnetized nanoscale Fe particles that are responsive to an external magnetic field. We suggest a porous PVDF membrane fabricated using a zinc oxide (ZnO) particulate leaching method as a backbone membrane of the ferro-actuator to increase the absorption of ferro-fluid. Ferro-fluid is absorbed on the porous PVDF membrane using a dip-coating method. First, we observe from scanning electron microscopic images the surfaces and cross sections of a pure PVDF membrane and the porous PVDF membrane using a ZnO particulate leaching method. Second, an energy-dispersive X-ray spectroscope is used to confirm the configuration of the elements and the absorption of Fe particles in the ferro-actuator. Third, we execute thermogravimetric analysis and X-ray diffraction analysis of the pure PVDF membrane, the PVDF membrane before/after particulate leaching, and of the ferro-actuator using the porous PVDF membrane. Through these analyses, we can confirm that ZnO particles in the PVDF membrane were clearly removed by the particulate leaching method and Fe particles were included in the fabricated ferro-actuator. Finally, we fabricate cantilever-type ferro-actuators using pure PVDF membrane and the porous PVDF membrane and execute blocking force and displacement tests. Compared with the ferro-actuator using the pure PVDF membrane, the ferro-actuator using the porous PVDF membrane had an increased displacements—about a 3-fold increase at the DC input and at the AC input, along with increased blocking force (about a 6-fold increase) at the DC input. Consequently, the concept that a ferro-actuator using the porous PVDF membrane exhibits enhanced actuating performance is validated.