Design and development of high-frequency actuator for nanocoining

INTRODUCTION Nanocoining is a technique developed at the PEC that can cover a surface with subwavelength features at very high speeds. The process has been described in previous papers at ASPE and the current work is focused on the design and fabrication of the 2D actuator that must operate ultrasonically with a specific ratio of vertical to horizontal motion. The heart of the device is an aluminum beam driven by piezoelectric actuators. The 20 μm square diamond die has been Focus Ion Beam (FIB) machined to produce 6400 posts each with an area of 250 nm square. The challenge in designing the actuator is creating two resonant modes with the same natural frequency and with amplitudes three times larger perpendicular to the workpiece than along it (FIGURE 1).