Steerable and Agile Light-Fueled Rolling Locomotors by Curvature-Engineered Torsional Torque

Jun-Chan Choi; Jisoo Jeon; Jae-Won Lee; Asad Nauman; Jae Gyeong Lee; Woongbi Cho; Chanwoo Lee; Young-Min Cho; Jeong Jae Wie; Hak-Rin Kim

doi:10.1002/advs.202304715

Steerable and Agile Light-Fueled Rolling Locomotors by Curvature-Engineered Torsional Torque

Adv Sci (Weinh). 2023 Oct;10(30):e2304715. doi: 10.1002/advs.202304715. Epub 2023 Aug 11.

Authors

Jun-Chan Choi^{1

2}, Jisoo Jeon³, Jae-Won Lee¹, Asad Nauman¹, Jae Gyeong Lee^{4

5}, Woongbi Cho^{4

5}, Chanwoo Lee¹, Young-Min Cho⁶, Jeong Jae Wie^{4

5

7

8

9

10

11}, Hak-Rin Kim^{1

6}

Affiliations

¹ School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
² Soft Hybrid Materials Research Center, Korea Institute of Science and Technology, 02792, Seoul, Republic of Korea.
³ Program in Environmental and Polymer Engineering, Inha University, 22212, Incheon, Republic of Korea.
⁴ Department of Organic and Nano Engineering, Hanyang University, 04763, Seoul, Republic of Korea.
⁵ Human-Tech Convergence Program, Hanyang University, 04763, Seoul, Republic of Korea.
⁶ School of Electronics Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
⁷ Department of Chemical Engineering, Hanyang University, 04763, Seoul, Republic of Korea.
⁸ Institute of Nano Science and Technology, Hanyang University, 04763, Seoul, Republic of Korea.
⁹ The Research Institute of Industrial Science, Hanyang University, Seoul, 04763, Republic of Korea.
¹⁰ The Michael M. Szwarc Polymer Research Institute, State University of New York College of Environmental Science and Forestry, Syracuse, NY, 13210, USA.
¹¹ Department of Chemical Engineering, State University of New York College of Enviromental Science and Forestry, Syracuse, NY, 13210, USA.

Abstract

On-demand photo-steerable amphibious rolling motions are generated by the structural engineering of monolithic soft locomotors. Photo-morphogenesis of azobenzene-functionalized liquid crystal polymer networks (azo-LCNs) is designed from spiral ribbon to helicoid helices, employing a 270° super-twisted nematic molecular geometry with aspect ratio variations of azo-LCN strips. Unlike the intermittent and biased rolling of spiral ribbon azo-LCNs with center-of-mass shifting, the axial torsional torque of helicoid azo-LCNs enables continuous and straight rolling at high rotation rates (≈720 rpm). Furthermore, center-tapered helicoid structures with wide edges are introduced for effectively accelerating photo-motilities while maintaining directional controllability. Irrespective of surface conditions, the photo-induced rotational torque of center-tapered helicoid azo-LCNs can be transferred to interacting surfaces, as manifested by steep slope climbing and paddle-like swimming multimodal motilities. Finally, the authors demonstrate continuous curvilinear guidance of soft locomotors, bypassing obstacles and reaching desired destinations through real-time on-demand photo-steering.

Keywords: amphibious multimodal actuation; helical soft robot; liquid crystal polymer network; on-demand steering; photo-mechanical rolling.

Abstract

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