A pendulum actuator for environmental vibration isolation based on magnetostrictive composite material

In precision optical experiments, optical devices are usually suspended by pendulum systems to isolate environmental vibration. However, a traditional pendulum vibration isolator only isolates the horizontal vibration. Here, a new type of pendulum actuator, which bases on giant magnetostrictive composite material, is proposed to achieve environmental vibration isolation. The core element in actuator is a flexible wire, which is made of a thin quartz fiber embedded in epoxy resin-bonded magnetostrictive composite material with Terfenol-D particles. The designed flexible wire is deformable in vertical direction and capable to isolate the vertical vibration. The experiments are performed to verify the performance of the actuator. The response of the actuator shows great linearity with a sensitivity of 0.78 μm/A to the driving current. It also shows a large elongation range up to 5.9 μm in the linear area. Furthermore, performance of actuator on environmental vibration isolation is tested. The peak-to-peak value of vibration along vertical direction can be reduced by 17.5 dB with no negative impact on vibration along horizontal direction, which corroborates the capability of the novel pendulum actuator to isolate the environmental vibration in precision measurement.