Piezoelectric actuators are fast replacing more traditional electromechanical devices due to their small size, high strain, low power consumption, linear response and fine control. A small selection from the constantly expanding list of applications includes:
- optical component positioning;
- pneumatic and hydraulic valve control – flow management or pumping e.g. fuel injection;
- oscillation control or vibration damping;
- movement in small robotic systems.
The relationship between displacement and actuation force is an important characteristic of any piezoelectric actuator. These devices convert electrical energy into force or motion or, under the varying load conditions experienced in many applications, the energy is split between generating displacement and force simultaneously when coupled to an external mechanical system. The proportion depends on the relative stiffnesses of the actuator and the resisting mechanics, with the energy conversion being a maximum where these are exactly matched.
In practice, the actual achievable stroke/load depends on mounting conditions, loading area and morphology, temperature, ageing, field-related material non-linearity etc. Often manufacturers’ specifications and performance data are defined in different ways, making it impossible to compare directly between actuators from several alternative suppliers. In addition, it is difficult to predict performance reliably, so that measurements made under anticipated operating conditions are usually recommended to assist in the choice between several actuators for a particular application. As a result, not only is design data scarce, but without any standard measurements its usefulness is severely limited.
For more information on how piezo materials may solve your actuation needs please contact Electrosciences.