The Delta-Motor: A multi-modal, high-speed, flexure-based piezoelectric motor

Here we present a new type of piezoelectric motor that uses flexures and a variable-transmission crank-shaft to produce both full rotary and linear actuation in the same device, at the same frequency as the input (piezoelectric drive) frequency. This multi-modal design weighs only 130 mg and has achieved rotational rates up to 30,000 RPM (orders of magnitude higher than typical piezoelectric motors) and a peak torque of 2.5 mu Nm. In the linear mode, it has demonstrated a blocked force of +/- 100 mN and a free displacement of +/- 0.6 mm up to at least 500 Hz in output frequency. The rotary and linear modes of operation can be activated independently (e.g., to switch gears) or simultaneously (to produce complex output motions).