Dome bilayer piezoelectric/electrostrictive (P/E) composite flextensional actuator

A new type of flextensional actuator called bilayer piezoelectric/electrostrictive dome unimorph (BIPEDU) is presented. The BIPEDU actuator is fabricated by attaching a dome piezoelectric-electrostrictive monolithic bilayer composite (PE-BMLC) actuator to a metallic plate by using insulating epoxy resin. In this study, a PE-MBLC with a P:E ceramic with volume ratio of 8:2 was used as the active driving element. The stainless steel plate acted as a flextensional structure. Under the application of an electric field, the force generated from the radial contraction of the PE-MBLC was transferred through the bonding area to deform the metallic plate, generating more displacement in the BIPEDU actuator. The effect of the bonding area between the PE-MBLC and the metal plate on the displacement was examined. It was found that complete and uniform bonding effectively transferred the force from the radial contraction of the PE-MBLC actuator to the metallic plate. As a result, the completely bonded BIPEDU actuator gave a higher displacement. In addition, the effect of various thicknesses of the stainless steel on the displacement in the BIPEDU was also investigated. Experimental results indicated that the BIPEDU fabricated by using 76 μm thickness stainless steel yielded the highest displacement of ≈ 65 μm. In comparison, the displacement of the BIPEDU actuator was about 12 times higher than that of the PE-MBLC actuator (~ 5 μm).