Optimal matching and interfacing of piezoelectric acuators within mechatronic applications

Successful use of piezoelectric actuators in mechatronic applications depends on three key factors in the conceptual design stage. First of all appropriate quantitative requirements need to be derived. Secondly, the piezoelectric actuator needs to be chosen to appropriately match the performance requirements, within both the available space and the allowed cost budget. Thirdly, the mechanical interface should be designed so as to ensure correct loading of the piezoelectric actuator. The impact of the mechanical interface often necessitates reconsideration of the quantitative requirements and thus leads to iterations in the search for the optimal piezoelectric actuator. In order to facilitate the iterative analysis and design process, the quantitative requirements can appropriately be expressed as characteristic lines and points in the socalled force-stroke diagram. This diagram allows for a transparent analysis of the key factors in the design problem, and as such for an optimal choice for the piezoelectric actuator in terms of e.g. design space, cost, and energy consumption.
This iterative design approach, with a central role for the force-stroke diagram analysis, will be illustrated for two mechatronic applications:
- a piezoelectric actuated valve, based on a d31 ceramic multilayer bender
- a piezoelectric stepping device., based on a d33 ceramic multilayer stack actuator