Alternate Evaluation Criteria of Piezoelectric Motors

Abstract

In this article, four types of piezoelectrically driven motors are evaluated: linear, horn-type, unidirectional rotary, and bidirectional traveling wave. Experimental results for velocity, power, and specific power are presented as a function of mechanical load. Analytical and experimental energy densities are compared based upon applied electrical potential. The bidirectional ultrasonic motor exhibited 34% of its available energy density, while the other motors produced values ranging from 0.63 to 9.5% of their respective available energies. The piezoelectric material specific power values ranged from 4500 W/kg for the bidirectional motor to 6.53 W/kg for the linear piezo motor. Results suggest that comparing piezoelectric motors based on individual mechanical parameters does not accurately describe motor design and drive train energy transmission.

Evaluating piezoelectric hydraulic pumps as drivers for pulsatile pediatric ventricular assist devices

“…While these motors have produced significant power outputs for their size, the mechanical translation through friction has limited power output. Tieck et al (2007) measured the intrinsic piezoelectric material power densities and compared them to the ultrasonic motor that utilized them. The intrinsic piezoelectric power densities ranged from 6.53 to 4500 W/kg, while the actual power densities of the motors spanned from 0.82 to 85.73 W/kg.…”

Modeling and Characterization of a Linear Piezomotor

“…One appealing embodiment of the vast literature on smart systems is the use of piezoelectric bimorphs since they offer various benefits over other designs such as the piezoelectric ultrasonic wave motors. For example, the bimorph motors provides high output power for a given torque and requires lower applied electric field (Tieck et al, 2007). Furthermore, the bimorph motors are generally very stiff and stable enabling very accurate load positioning with accuracies which are in the neighborhood of 10 nm (http://www.piezomotor.se/).…”

“…Furthermore, the bimorph motors are generally very stiff and stable enabling very accurate load positioning with accuracies which are in the neighborhood of 10 nm (http://www.piezomotor.se/). However, these performance metrics occur at the expense of higher motor weight, low travel speeds, and low overall efficiency (Tieck et al, 2007).…”

“…Comparisons are established between the theoretical predictions and the experimental results in order to validate the developed finite element model. Such an effort is aimed to parallel the efforts exerted by Vinhais et al (2004) to analyze the horn type piezomotor developed by Hill (2002) which has lower load capacity, lower output power, and higher applied electric field than the piezoelectric bimorph motor (Tieck et al, 2007). This remainder of this article is organized into three sections.…”

Development of a low-voltage piezohydraulic pump for compact hydraulic systems

“…Tieck et al demonstrated that the use of friction to rectify piezoelectric strain effectively reduces the total power output that is transmitted from the high density piezoelectric actuator to the load [5]. Electrohydraulic pumps use an incompressible fluid and two one-way valves to convert the small displacements of an electroactive stack actuator into a continuous flow of pressurized fluid for mechanical work.…”