Abstract
This paper proposes a design methodology for a two-stage linear micro-feeding system that includes a coarse-feeding subsystem, a fine-feeding subsystem and positioning subsystem. The coarse stage is driven by an array of thermal actuators through a compliant amplification mechanism. This gives it the ability to generate a rapid and long range of motion. When the coarse-feeding subsystem is moved to the desired position, the system is clamped by the positioning subsystem that features two compliant bistable mechanisms. The coarse-feeding subsystem has a range of 60 μm with a resolution of 3 μm. After the coarse stage moves into the desirable position, the scratch drive actuator shifts the fine stage to the desired position over a small range of 4 μm, with a large force of 165 μN, and a high resolution of 30 nm at a bias of 70V with an additional sine wave of amplitude 20V. Additionally, the pseudo-rigid-body model and Castigliano’s theorem were employed to derive the strain energy and the relationship between the output and input displacements of the amplification mechanism. These theorems were tested and matched the experimental results. The results of the experiments performed support the pseudo-rigid-body model and the widely accepted Castigliano’s method. The proposed micro-feeding system was fabricated by the MUMPs, which was provided by MEMSCAP.