A Multi-Layer Diaphragm Flexure With a Spatial Interconnect Structure

Abstract Diaphragm flexures generate guided out-of-plane motion while providing in-plane load bearing for a broad range of precision applications. This paper presents a novel multi-layer diaphragm flexure design that exhibits optimal bearing performance (i.e. low stiffness in the out-of-plane direction and high stiffness in the in-plane directions) and nearly zero parasitic rotation about the out-of-plane translational direction, simultaneously. The new design consists of a multi-layer arrangement of two identical diaphragm flexures comprising “nested flexure beams”, spaced apart along the out-of-plane direction. The two corresponding diaphragms, the two corresponding ground frames, and every pair of the corresponding unsupported ends of the nested beams are interconnected between the upper and lower layers. Additionally, the unsupported ends of the nested beam are also interconnected within each respective upper and lower layer. Analytical models are presented for the in-plane and out-of-plane stiffness of the proposed design that closely match Finite Element Analysis (FEA) results. The novel design proposed in this paper offers a simpler interconnect structure compared to the previous design comprising folded flexure beams, facilitating the manufacturing and assembling processes and leading to a lighter sandwich design with more favorable dynamic performance.