Linear Piezoelectric Actuator

Linear actuators have been developed in many research fields and industries because of the increased demand for high precision positioning systems. Especially, linear actuators were recently employed to a component in various types of camera equipment such as a zoom, Image stabilizer.
I would like to tell you about linear actuators that I have developed. One of actuators that I involved is Tiny Ultrasonic Linear Actuator (TULA). Actually, I didn't evolve the development of  this actuator it self but  I have studied on control method for this actuator. The reason why I'd like to introduce about it is that it's one of the very interesting and attracting linear actuators. The structure and principle of this actuator shows below.



1. Structure and principle of TULA (HP Ko et al., 2006 and WS Jung et al., 2009)



As shown, it has very simple and tiny structure. The diameter of this actuator I used is approximately Ø3 mm. it uses inertia displacement. For instance, the shaft and mobile element goes up together when the shaft slowly goes up, and then if the shaft goes down quickly, the shaft goes down, leaving the mobile element because of the inertia displacement, and vice versa. If you want to know its information more, please take a look at www.piezo-tech.com. For your convenience to understand this linear actuator, I inserted movies below (from Piezo-tech.com).