Design and fabrication of a multi-degree-of-freedom microactuator using symmetric piezoelectric pusher element 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 with a Vickers hardness value (HV) of 550, 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 research integrated the concept of LEGO^® bricks, and three different vibration modes of the SPPE were designed to develop a high-power MDOF motion platform, which was 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. The experiment demonstrated the high-power MDOF eyeball-like microactuator working frequencies along the X-, Y-, and Z-axes to be 223.4 kHz, 223.2 kHz, and 225 kHz and the rotation speeds to reach 50 rpm, 52 rpm, and 180 rpm, respectively, at a driving voltage of 30Vpp. In the future, this MODF eyeball-like microactuator may be used for a number of applications, such as sun-tracking systems for green energy harvesters and eyeball-like devices for use in the biomedical field.