Comparison of Piezoelectric, Magnetostrictive, and Electrostrictive Hybrid Hydraulic Actuators

Abstract

In recent years, active material driven actuators have been widely researched for potential applications in the fields of aerospace, automotive, and civil engineering. While most of these active materials, such as piezoelectric, magnetostrictive, and electrostrictive materials, have high force and bandwidth capabilities, they are limited in stroke. In combination with hydraulic systems, the field-dependent motion of these materials can be amplified to produce high force, high stroke actuators. In a hybrid hydraulic pump, the motion of an active material is used to pressurize a hydraulic fluid. Since the properties of active materials vary greatly in terms of free strain and block force, there is a need to identify the optimum active material for a particular application. This study compares four active materials, Lead—Zirconate—Titanate (PZT), Lead—Magnesium—Niobate (PMN), Terfenol-D and Galfenol, as the drivers of a hybrid hydraulic actuation system. The performance of each of these active materials has been evaluated in the same hydraulic actuator through systematic testing of the actuator while maintaining the same length and volume for each active material. In each case, the active material has a length of around 54 mm and a cross-sectional area of 25 mm2. Commonly used metrics such as output power and electromechanical efficiency are used for comparison. Of the four materials tested in this study, PMN presented the largest free strain (2000 με), while Galfenol presented the least (300 με). The highest no-load velocity is also exhibited by the PMN-based actuator (270 mm/s). The maximum output power obtained is 2.5 W for both PMN and Terfenol-D-based actuators while the highest electromechanical efficiency obtained is 7% for the PMN-based actuator.

Piezoelectric Inertia Motors—A Critical Review of History, Concepts, Design, Applications, and Perspectives

“…Electro-and magnetostriction are effects similar to piezoelectricity causing solids to deform in an electric or magnetic field, respectively. A comparison of the three effects can be found in [196]. The use of electrostriction in inertia motors has been proposed in several patent applications [197][198][199][200][201][202], but no realisation is known to date.…”

Design and Simulation of Electromagnetic Linear Actuators for Jet Dispensers

“…Finite element analysis (FEA) simulations are then performed to determine the thrust force produced by each actuator under typical stroke-length and excitation-current conditions. Further simulations Piezo-stack actuators (PSAs) and magnetostrictive actuators (MSAs) generate a high thrust force but have a stroke length of just 100 µm [17]. For most practical applications, the stroke length needs to be magnified by a factor of at least three times.…”

Design and Experiment of a Moving Magnet Actuator Based Jetting Dispenser

“…The deformation in this PSA is not great enough to directly actuate the needle displacement. Thus, an amplification mechanism including a hinge and lever is used to magnify the displacement to at least 0.35 mm [19,20]. The PSA has two major designs, in which one or two PSA blocks combined with the amplification mechanism and return spring are used, as indicated in Figure 2a,b.…”