Flexigami : folded polygonal unit cells for deployable metamaterials and mechanisms

Deployable and transformable structures are of broad interest for applications including satellites and space exploration, temporary shelters, packaging, transportation, robotics and medical devices. One emerging approach to scalable fabrication of such structures involves the general concept of Origami-inspired design along with cutting, folding, and fastening of sheet materials. However, contrasting the classical approach of modeling Origami structures as having perfect hinges and rigid panels, consideration of the finite bending and rotational stiffness of these elements is essential to understand their constituent mechanics. Moreover, meta-materials and functional structures having fundamentally new mechanical properties can be designed this way. We present the design, fabrication and mechanics of a novel, deployable cellular material, which we call Flexigami. The unit cell takes the form of two parallel regular polygons, connected by a circuit of diagonally creased panels. Upon compression, individual unit cells transform either gently or abruptly between two stable equilibrium states depending on the interplay between hinge and panel properties. The mechanical behavior of each unit cell can be deterministically designed via geometry, dimensions and topology of the panels and hinges. Individual unit cells can collapsed reversible to less than 10% of their deployed volume. Within this transition regime, the force-displacement curve of each cell can be tuned to exhibit a smooth compression behavior or an instability followed by a self-reinforcing response. We use finite-element models complemented by analytical and computational analysis of the results to understand the importance of different mechanical properties of constituent hinges and panels and also demonstrate the fabrication of flexigami cells and mechanisms in various structural materials. Finally we present different mechanisms and their subsequent applications.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2016

Author dc:creator

• Nayakanti, Nigamaa

Advisor dc:contributor.advisor

• John Hart.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/104281

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/104281