A three-dimensional compliant bowtie-shaped mechanical amplifier to magnify coaxial displacement in a confined space

This paper proposes a novel form of a three- dimensional coaxial bowtie-shaped mechanical amplifier. The proposed model incorporates a lever mechanism into the Sarrus linkage structure. It allows the target plate to move along one axis with amplified displacement in a parallel manner. The amplifier was assembled after machining the components using a computer numerical control machine. A flexible hinge was incorporated into the amplifier design for simplified fabrication and reduced friction in the actuation mechanism. Castigliano’s theorem is used to build a mathematical model of the pro- posed mechanical amplifier, and the performance was validated through finite element analysis and prototype fabrication. We achieved the amplification ratio of ×8.44, resulting in the axial displacement up to 86 μm. The demonstrated amplifier is ex- pected to apply to compact microsurgical robots or biomedical imaging apparatus requiring coaxial displacement amplification in confined spaces.