Precisely Controllable Artificial Muscle with Continuous Morphing based on "Breathing" of Supramolecular Columns

Zifan Yang; Jiahua Li; Xu Chen; Yining Fan; Jin Huang; Haifeng Yu; Shuang Yang; Er-Qiang Chen

doi:10.1002/adma.202211648

Precisely Controllable Artificial Muscle with Continuous Morphing based on "Breathing" of Supramolecular Columns

Adv Mater. 2023 Apr;35(14):e2211648. doi: 10.1002/adma.202211648. Epub 2023 Feb 25.

Authors

Zifan Yang¹, Jiahua Li¹, Xu Chen¹, Yining Fan¹, Jin Huang², Haifeng Yu³, Shuang Yang¹, Er-Qiang Chen¹

Affiliations

¹ Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Mater Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China.
² Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing, 100871, P. R. China.
³ School of Materials Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing, 100871, P. R. China.

PMID: 36634260
DOI: 10.1002/adma.202211648

Abstract

Skeletal muscles are natural motors executing sophisticated work through precise control of linear contraction. Although various liquid crystal polymers based artificial muscles have been designed, the mechanism based on mainly the order-disorder transition usually leads to discrete shape morphing, leaving arbitrary and precise deformation a huge challenge. Here, one novel photoresponsive hemiphasmidic side-chain liquid crystal polymer with a unique "breathing" columnar phase that enables continuous morphing is presented. Due to confinement inside the supramolecular columnar assembly, the cooperative movements of side-chains and backbones generate a significant negative thermal expansion and lead to temperature-controllable muscle-like elongation/contraction in the oriented polymer strip. The irreversible isomerization of the photoresponsive mesogens results in the synergistic phototunable bending and high-contrast fluorescence change. Based on the orthogonal responses to heat and light, controllable arm-like bending motions of this material, which is applicable in constructing advanced artificial muscles or intelligent soft robotics, are further demonstrated.

Keywords: artificial muscle; columnar liquid crystal phase; dual photoresponse; quantitatively elongation and bending; side-chain liquid crystal polymers.