Piezo-Electric Linear Actuators in Vacuum

Abstract

Piezo-electric motors and actuators are routinely used in terrestrial applications. These applications range from rotary motors for auto-focusing mechanisms in cameras, to micro-pump systems in medical implants. In space applications linear actuators are used in a variety of instruments and mechanisms. An understanding of the behavior of such devices is therefore imperative.

This paper presents an assessment into the performance of three linear actuator devices of interest to the space industry under thermal vacuum conditions performed at ESTL. The three actuators assessed are a PI (Physik
Instrument) Nexline N110 step/walk device, a Squiggle SQ 125 UHV-N ultrasonic motor, and a Nanomotion
FB050/HR4 actuator. Within the text, these actuators will be referred to as the ‘Nexline’, ‘Squiggle’, and
‘Nanomotion’ devices respectively.

Each actuator shall be discussed separately, and it should be stressed that a direct comparison between the devices is not drawn from the testing. Testing of each actuator is typically done through a combination of drive force measurements, and life tests.