Lamina emergent compliant mechanisms (including origami-adapted compliant mechanisms) are mechanical devices that can be fabricated from a planar material (a lamina) and have motion that emerges out of the fabrication plane. Lamina emergent compliant mechanisms often exhibit undesirable parasitic motions due to the planar fabrication constraint.

A bilayer membrane-enhanced outside LET joint.

Membrane-enhanced lamina emergent torsion (M-LET) joints were developed that constrain motion in unde-sired directions while not limiting motion in the direction in which the joint is designed to move. This technology consists of a LET joint that reduces parasitic motions of lamina emergent mechanisms (LEMs) and presents equations for modeling parasitic motion of LET joints.

M-LET also makes possible a one-way joint that can ensure origami-based mechanisms emerge from their flat state (a change point) into the desired configuration. The membrane adds a minimal increase in stiffness in the desired direction of motion, but it significantly increases stiffness in directions in which the traditional LET joint has undesired parasitic motion. The integration of M-LET joints as surrogate folds can reduce parasitic motions and increase precision and repeatability.

The invention is useful for developing high-performance, origami-inspired compliant mechanisms where high accuracy and high repeatability are required.

For more information, contact Spencer Rogers at This email address is being protected from spambots. You need JavaScript enabled to view it.; 801-422-3676.

Tech Briefs Magazine

This article first appeared in the January, 2019 issue of Tech Briefs Magazine.

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