Introduction: The document discusses the design challenges associated with piezo-actuators, which are mechanisms that utilize piezoelectric materials for precision motion capabilities. DSM has developed strategies to address these challenges, focusing on issues such as reactive energy, hysteresis, creep, temperature instability, spring effects, and energy losses.

Reactive Energy: Piezo-actuators require a significant amount of current from the driver to produce the desired electrical field. Due to the high capacitance of PZT stacks, most of the energy is reactive power. The drive electronics must be specialized for capacitive loads, similar to a four-quadrant drive for a DC motor.

Hysteresis, Creep, and Temperature Instability: Hysteresis in piezoelectric actuators results in a non-linear correlation between voltage and strain, with open-loop hysteresis around 10-15% of full scale. Temperature changes can cause dipole creep, leading to mechanical drift. DSM recommends using displacement feedback for fine resolution.

Spring Effects: Piezo-actuators behave like springs, with force decreasing as they extend. The stiffness of the actuator and the forces against it must be considered to ensure proper operation. DSM specializes in high stiffness actuators for long stroke/high force performance.

Energy Losses from Compliance: Mechanical slop or backlash in the actuator system reduces available work. DSM advises collaborating with a competent actuator designer to develop suitable connections and mounting systems.

Conclusion: The document highlights the importance of addressing these design challenges to optimize the performance of piezo-actuators in various applications.