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Published January 20, 2023 | Published + Supplemental Material
Journal Article Open

Leaping liquid crystal elastomers


Snap-through mechanisms are pervasive in everyday life in biological systems, engineered devices, and consumer products. Snap-through transitions can be realized in responsive materials via stimuli-induced mechanical instability. Here, we demonstrate a rapid and powerful snap-through response in liquid crystalline elastomers (LCEs). While LCEs have been extensively examined as material actuators, their deformation rate is limited by the second-order character of their phase transition. In this work, we locally pattern the director orientation of LCEs and fabricate mechanical elements with through-thickness (functionally graded) modulus gradients to realize stimuli-induced responses as fast as 6 ms. The rapid acceleration and associated force output of the LCE elements cause the elements to leap to heights over 200 times the material thickness. The experimental examination in functionally graded LCE elements is complemented with computational evaluation of the underlying mechanics. The experimentally validated model is then exercised as a design tool to guide functional implementation, visualized as directional leaping.

Additional Information

© 2023 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). This work was supported by the National Science Foundation Graduate Research Fellowship DGE 1650115 (to T.S.H.), National Science Foundation (DMR 2105369, to T.J.W.), and the U.S. Office of Naval Research through Multi-investigator University Research Initiative Grant (ONR N00014-18-1-2624, to K.K. and K.B.). Author contributions: Conceptualization: T.J.W., C.N.B., and T.S.H. Experimental study: T.S.H. Computational study: K.K. and K.B. Supervision: T.J.W., C.N.B., and K.B. Writing—original draft: T.S.H., K.K., and T.J.W. Writing—review and editing: All authors. Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper, the Supplementary Materials, or in a repository that can be found at doi.org/10.22002/stjfa-f1372. The authors declare that they have no competing interests.

Attached Files

Published - sciadv.ade1320.pdf

Supplemental Material - sciadv.ade1320_movies_s1_to_s14.zip

Supplemental Material - sciadv.ade1320_sm.pdf


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Additional details

August 22, 2023
October 23, 2023