641820 event 1607003999 1607003999 <![CDATA[PhD Defense by Larissa Simoes Novelino]]> Ph.D. Thesis Defense Announcement

Multifunctional Origami: From Architected Metamaterials to Untethered Robots

 

by

Larissa Simoes Novelino

 

Advisor(s):

Dr. Glaucio H. Paulino

 

Committee Members:

Dr. Abdul-Hamid Zureick (CEE), Dr. Jerry Qi (ME), Dr. Yves Klett (University of Stuttgart)
Dr. Paolo Gardoni (University of Illinois at Urbana–Champaign)

 

Date & Time: Dec 16th - 1pm

 

Location: https://zoom.us/j/7775875977

Origami has unfolded engineering applications in various fields, such as electrical, civil, aerospace, biomedical, and materials engineering. Those applications take advantage of the origami shape change capabilities to create tunable, deployable, and multifunctional systems. Although origami has catalyzed innovative solutions for such systems, its feasibility is challenged by pervasive pragmatic aspects. Thus, this thesis focuses on the aspects that must be addressed for multifunctional origami applications, such as geometric imperfections, manufacturing, multiphysics considerations, and actuation strategies across scales.  Specifically, we study how geometric imperfections, which may be inevitable formed during fabrication or service of origami systems, can impact both geometric and mechanical properties of origami patterns. We use experiments and numerical simulations to demonstrate quantitatively how geometric imperfections hinder the foldability of the origami pattern while increasing its compressive stiffness. Regarding the manufacturing aspect, we miniaturize origami toward the micro-scale and create architected metamaterials with remarkable mechanical properties, e.g., stiffness and Poisson’s ratio tunable anisotropy, large degree of shape recoverability, and reversible auxeticity. Our findings emphasize the scalable and multifunctional nature of origami designs. On the multiphysics aspect, we examine the coupling of mechanical and electromagnetic fields by using origami to fabricate spatial filters – frequency selective surfaces with dipole resonant elements placed across the origami creases. The electrical length of the dipole elements changes as the origami pattern changes through folding states, making the spatial filters reconfigurable over a continuous range.  The fabricated structures feature the unprecedented capability of on-the-fly reconfigurability to different specifications (multiple bands, broadband/narrowband bandwidth, wide angle of incidence rejection), requiring neither specialized substrates nor highly complex electronics, holding frames, or fabrication processes. Finally, we introduce an untethered actuation solution with direct applications to origami-inspired robotics, morphing structures, metamaterials, and multifunctional devices with multiphysics responses. Our solution couples geometric bi-stability and magnetic-responsive materials, allowing for instantaneous shape locking and local/distributed actuation with controllable speed, which can be as fast as a tenth of a second. We apply the proposed actuation to create origami micro-robots that feature shape-changing, computing, and sensing capabilities. 

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