Spherical lamina emergent mechanisms

Lamina emergent mechanisms (LEMs) are compliant mechanisms that can be manufactured from planar materials and are capable of motion out of the plane of manufacture. Spherical LEMs combine the unique motion of spherical mechanisms with the compactness and simple topology of LEMs. The fundamentals of spherical LEMs are discussed in this work. It is found that 21 of the 33 possible spherical 4R types can be spherical LEMs. A classification based on these 21 possible types is developed. This classification is used to predict motion capabilities of spherical 6R mechanisms. It is also applied to arrays of spherical mechanisms. The extreme compactness and sophisticated motion of spherical LEMs makes them candidates for application that are weight and volume sensitive and may find use in future surface morphing applications.

► We introduce the fundamentals of spherical lamina emergent mechanisms (LEMs).
► It is found that 21 of the 33 possible spherical 4R types can be spherical LEMs.
► We evaluate spherical 6R mechanisms and arrays of spherical mechanisms.
► Spherical LEMS offer extreme compactness and sophisticated motion.