A linear actuator creates motion in a straight line, and is useful when the application requires objects to be moved in a linear direction. Actuators are mostly classified based on the power source that drives them. Thus, there are hydraulically and pneumatically operated actuators, there are voice coil actuators, and there are piezoelectric actuators. Each actuator type has its drawbacks and advantages. These actuators are used in industrial, commercial, and even consumer applications.
Piezoelectric actuators are widely preferred because they can move loads in the sub-nanometer range, as well as loads that weigh several tons.
How do piezoelectric actuators function?
Such actuators derive their energy from the piezoelectric effect. The piezoelectric effect can be seen in multiple applications in our daily life. Cigarette lighters and stove lighters function based on this effect. A certain group of solid-state crystals tend to change shape when they are exposed to an electric potential.
Thus, these materials can convert electric energy into mechanical energy (movement). They also have the potential to convert mechanical energy into electrical energy. The science of precision positioning and accurate motion control has undergone a sea change owing to the development and advancement of piezoelectric actuators. A piezoelectric linear slide can also function on the same principles of piezoelectricity.
Here are some characteristics demonstrated by a piezoelectric linear actuator:
It can move loads in the sub nano-meter range, as well as loads that weigh several tons.
These actuators primarily function on motion derived from piezoelectric materials. Owing to this attribute, they need to moving or sliding parts to cause actuation. This reduces friction and mechanical lag.
Since there are no moving parts and no resultant friction, there is no wear. The overall maintenance required for a piezoelectric actuator is very low.
Designs in piezo linear actuators
Piezo actuators can be configured in several different ways. The design can be optimized to suit hundreds of different applications. Here are some common actuator designs:
Guided piezo actuators: These actuators comprise highly evolved nano positioners with integrated piezo drives, and solid state flexures. They are used when exceptionally straight and flat or multi-axis motion (up to 6 axes) is required.
Stack actuators: This particular actuator design is used when high force needs to be generated. Manufacturers can offer stack actuator units that produce travel ranges up to 500 nano meters.
Piezo tube actuators: This linear actuator category exploits the radial contraction direction. Devices such as micro pumps and scanning microscopes make use of piezo tube actuators.
Though these three are the commonly-used actuator types, there are other configurations such as bender and bimorph actuators, and even shear elements. A piezoelectric linear actuator needs to be selected with care, and as a buyer, you might want to engage the services of a reputable global firm that manufactures high-performance piezo actuators.
