Extremely Large Deflection Actuators for Translation or Rotation

In this paper we propose a new type of piezoelectric microactuator to produce extremely large translational (> 100 microns) or rotational deflections (> 10 degrees). Many micro electro mechanical systems (MEMS) are capable of deflecting 1 to 10s microns using the electrostatic or thermoelectric phenomenon. The problem with electrostatic actuators is that they are usually constrained to operate in clean environments, which limits their utility to physically interact with the environment. The problem with thermal actuators is that they usually require a relatively large amount of power since they rely on heat. Achieving large deflection actuators without such constraints may find applications in biomedical engineering, optics, micro/nano-assembly, scanning probe microscopy, etc. What is novel about our piezo actuator is we exploit lateral deflection to create an actuator that forms an ‘S’ shape upon actuation. We then explore the use of this S-drive for large translational and rotational actuators. For feasibility analysis, we consider nonlinear deflection, voltage limit due to dielectric breakdown, strain limit, and gravitational effects.