Arbitrary axis rotating surface acoustic wave micro motor

We present a surface acoustic wave (SAW) actuated rotating micro motor. The rotors are 1 millimeter metal spheres which are placed on the surface of a Lead Zirconate Titanate (PZT) substrate with IDTs designed to generate SAW with ~ 700 m wavelength. A Laser Doppler Vibrometer (LDV) was used to visualize the travelling SAW and the result was compared with the rotation of the rotor. The motor transient responses are presented, along with its torque-speed curve. The maximum rotational speed and torque reported were ~1000 rpm and ~14 N.mm, respectively. Arbitrary motions have also been demonstrated utilizing a magnetic pre-load and multiple IDTs activation.