Piezoelectric actuators are devices that can convert electrical energy into mechanical energy using the piezoelectric effect. The piezoelectric effect is a phenomenon where certain materials, such as crystals or ceramics, generate an electric charge in response to applied mechanical stress, and conversely, they deform when an electric field is applied to them. This bidirectional behavior allows piezoelectric materials to function as both sensors and actuators.
Here's how electrical energy is converted into mechanical energy in piezoelectric actuators:
Application of an electrical voltage: When an external electric voltage is applied to the piezoelectric material, it causes a deformation in the crystal structure or lattice of the material due to the movement of charged particles within the material.
Induced mechanical strain: The applied voltage causes a change in the dimensions of the piezoelectric material, leading to mechanical strain or displacement. The amount of strain is directly proportional to the magnitude of the applied voltage.
Actuation response: The induced mechanical strain or displacement results in the actuation response of the piezoelectric actuator. This response can be used to produce precise and fine movements, making piezoelectric actuators suitable for applications requiring high precision, such as in nanopositioning systems, micro-robots, medical devices, and more.
Reversibility: It's important to note that the piezoelectric effect is reversible. When an external mechanical force or stress is applied to the piezoelectric material, it generates an electric charge across the material. This property allows piezoelectric actuators to be used as sensors as well, converting mechanical signals into electrical signals.
Overall, the conversion of electrical energy into mechanical energy in piezoelectric actuators is achieved through the application of an electric field to induce mechanical strain in the piezoelectric material, resulting in actuation or movement. The specific design and configuration of the actuator will determine the range of motion, force, and response characteristics it exhibits.