Bifurcation of self-folded polygonal bilayers

Journal Article · Tue Sep 05 00:00:00 EDT 2017 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.5001699· OSTI ID:1535344

Abdullah, Arif M. ^[1]; Braun, Paul V. ^[1]; Hsia, K. Jimmy ^[2]

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1. Univ. of Illinois at Urbana-Champaign, IL (United States)
2. Univ. of Illinois at Urbana-Champaign, IL (United States); Carnegie Mellon Univ., Pittsburgh, PA (United States)

Motivated by the self-assembly of natural systems, researchers have investigated the stimulus-responsive curving of thin-shell structures, which is also known as self-folding. Self-folding strategies not only offer possibilities to realize complicated shapes but also promise actuation at small length scales. Biaxial mismatch strain driven self-folding bilayers demonstrate bifurcation of equilibrium shapes (from quasi-axisymmetric doubly curved to approximately singly curved) during their stimulus-responsive morphing behavior. Being a structurally instable, bifurcation could be used to tune the self-folding behavior, and hence, a detailed understanding of this phenomenon is appealing from both fundamental and practical perspectives. In this work, we investigated the bifurcation behavior of self-folding bilayer polygons. For the mechanistic understanding, we developed finite element models of planar bilayers (consisting of a stimulus-responsive and a passive layer of material) that transform into 3D curved configurations. Our experiments with cross-linked Polydimethylsiloxane samples that change shapes in organic solvents confirmed our model predictions. Finally, we explored a design scheme to generate gripper-like architectures by avoiding the bifurcation of stimulus-responsive bilayers. Our research contributes to the broad field of self-assembly as the findings could motivate functional devices across multiple disciplines such as robotics, artificial muscles, therapeutic cargos, and reconfigurable biomedical devices.

• Research Organization: Univ. of Illinois at Urbana-Champaign, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: FG02-07ER46471
• OSTI ID: 1535344
• Alternate ID(s): OSTI ID: 1378393
• Journal Information: Applied Physics Letters, Vol. 111, Issue 10; ISSN 0003-6951
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Physics