The Technology
The capabilities of piezoelectric stacks actuators are still limited in terms of induced strains and travel range due to the materials operational range. They also have reduced resistance to large mechanical loads in the direction of movement.
Many piezoelectric materials are also ferroelectric. Under high level of stress or electric field, these materials change and give rise to considerably larger strains. The relation between the stress and the strain is non-linear and complex and is not simple to use.
Using an advanced piezoelectric – ferroelectric stack actuator with separate voltage control of each layer and prestressing the stack to induce a prescribed level of compressive stress allows operation in the ferroelectric non-linear range and produce large displacements. Additional standard piezoelectric layers can be used to smooth the device movement.
Advantages
- Large displacement rate by 4 to 10 over standard actuators
- Compact actuators
- Operation against higher mechanical resistance
Applications and Opportunities
- Fuel injectors
- Wafer positioning
- Microscopy
