Research highlights

Innovative microactuators: Compact 3.5 mm cubic rotary-linear piezoelectric actuator

Microactuators are critical components for industrial applications such as MEMS, micro-medical devices, and microrobotics. However, the fabrication of increasingly sophisticated, millimeter sized microactuators is complicated and proving to be a challenge.

Here, in an innovative approach, Tomoaki Mashimo has fabricated a miniature rotary-linear piezoelectric actuator with a single cubic stator with a side length of only 3.5 mm, which is capable of generating both rotary motion around its central axis and linear motion in the axial direction.

The stator consisted of a single metallic cube with a side length 3.5 mm, a 2.5-mm-diameter through-hole, and four piezoelectric elements bonded to the sides of the stator. The simplicity of the design enabled the fabrication of a compact actuator, without requiring any special manufacturing procedures.

The resultant rotary and linear velocities obtained were approximately 24 rad/s and 80 mm/s, when the applied voltage was 42 Vrms at each resonant frequency. The maximum torque and thrust force were 2.5 μNm and 2.6 mN, respectively.

Mashimo expects further miniaturization and improvement in the performance of this compact actuator. “We foresee micro-robotic and medical applications using the rotary-linear piezoelectric microactuator,” says Mashimo. “The microactuator simple design lends itself to many other applications as well.”

• Tomoaki Mashimo¹, and Shigeki Toyama²
• Rotary-Linear Piezoelectric Actuator with a Cubic Stator of Side Length of 3.5 mm
• IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 57, pp. 1825–1830, (2010).
• Digital Object Identifier (DOI): 10.1109/TUFFC.2010.1621
• ¹Tomoaki Mashimo is now at the Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology.
• ²Tokyo University of agriculture and Technology, department of Mechanical system Engineering, Tokyo, Japan.
• Related website: Electronics-Inspired Interdisciplinary Research Institute (EIIRIS) http://www.eiiris.tut.ac.jp/