Stick-Slip Piezoelectric Actuators

The following two photographs show a linear stick-slip actuator and a rotary stick-slip actuator. These actuators were designed and built in the Engineering Department.

Two types of piezoelectric stick-slip actuators

Linear Stack Actuator	Rotary Stack Actuator

The following results show the stick-slip motion for the linear and rotary actuator for forward motion only. The ceramic was excited using an asymmetric ramp wave.

Some results with the two types of actuators for forward motion

Linear Stack Actuator	Rotary Stack Actuator

The following to plots show the performance of the actuator for forward and reverse motion at different frequencies. Note that the maximum achievable velocity for forward and reverse motion are different.

Velocity vs frequency for both actuators

Linear Stack Actuator	Rotary Stack Actuator

Velocity vs frequency for different static friction forces for LSA

LSA 3d	LSA 2d

Advantages of the stick-slip actuators:

• Mechanical Simple, only a few parts are required
• No lubrication is required, lubrication in space would evaporate
• Resolution is driven via software
• Closed loop system could easyly be implemented
• Compact design

Disadvantages of the stick-slip actuators:

• Different behaviour for forward and reverse motion
• The rotary actuator requires a ground and polished surface in order to allow continuous and accurate motion

Last updated on the 4th of April, 1998