High-Bending-Stiffness Connector (HBSC) and High-Authority Piezoelectric Actuator (HAPA) Made of Such

High-authority piezoelectric actuator (HAPA) is a term used to describe high-performance piezoelectric actuators of relatively large displacement (≥50 μm) and high blocking force (≥100 N), but compact in size. One such piezoelectric actuator is described in this paper, which is made possible by means of high-bending-stiffness connector (HBSC) that connects multiple commercial piezoceramic stacks into a stable 2- (or multi-) level actuation configuration. Key design requirements for the HBSC are described. Computer simulation results and experimental verification are presented. A HAPA-(2 + 2) actuator was fabricated from such a HBSC, in which there are two commercial PZT stacks projecting upwards in the upper level and two projecting downwards in the lower lever, all of 5 × 5 mm2 in cross-section and 40 mm in length. The HAPA-(2 + 2) actuator prototype displays about twice the overall stroke and blocking force of individual stacks, being about 90 μm and >1600 N, respectively. This compares favorably with lever-arm, flextensional, and telescopic actuators, of which the blocking force is adversely affected. Using a similar concept, HBSCs and HAPAs of other designs are presented. In addition to being stand-alone actuators, the HAPAs can be used as the active material to drive existing displacement amplification schemes to produce piezoelectric actuators of exceptional performance characteristics