Design and evaluation of a multi-degree-of-freedom piezoelectric microactuator and its applications

A novel multi-degree-of-freedom (MDOF) microactuator was developed using a symmetric piezoelectric plate and a Ni-Co alloy micro-pusher element. A LIGA-like technique was employed to manufacture a Ni-Co alloy micro-pusher, which was then attached at the midpoint of the long side of a piezoelectric plate with dual electrodes to construct a symmetric piezoelectric pusher element (SPPE). The proposed approach integratese the concept of bricks and three different SPPE vibration modes were designed to develop a MDOF motion platform able to rotate a spherical device along three perpendicular axes. This MDOF microactuator consisted of a stator and a rotor. The stator was created from two mutually orthogonal sets of parallel SPPEs to form a MDOF motion platform, and the rotor was a spherical device. Experiments demonstrated the MDOF microactuator with working frequencies along the X, Y, and Z axes of 223.4 kHz, 223.2 kHz, and 225 kHz, respectively, and the respective rotation speeds reached 50 rpm, 52 rpm, and 180 rpm. This MODF microactuator may be used in a number of applications, such as sun-tracking systems for green energy harvesters and devices which can - eyeball-like - simultaneously and autonomously rotate along three axes for use in the biomedical field.