Light-powered self-propelling boat via self-rotating liquid crystal elastomer rod

doi:10.1007/s10483-026-3378-8

摘要/Abstract

Abstract:

Light-driven self-excited soft swimming systems based on liquid crystal elastomers (LCEs) offer a promising route toward autonomous motion. However, existing designs commonly rely on non-equilibrium oscillatory actuation and large-area or spatially distributed illumination. Here, we present a light-powered self-propelling boat actuated by a self-rotating LCE rod that operates around a steady-state equilibrium under static parallel illumination. While swimming, parallel light continuously irradiates the rod without the need for large-area coverage or moving illumination. A coupled theoretical model incorporating heat conduction and photomechanical response is developed to elucidate the self-propulsion mechanism. Analytical expressions for the light-induced lateral curvature and driving moment are derived to characterize the self-rotating dynamics. Numerical simulations reveal how the rod radius, light intensity, and support span influence the self-rotation angular velocity and self-propulsion speed. Experiments validate the theoretical predictions and demonstrate autonomous self-propulsion under static parallel illumination without moving light fields. The proposed system establishes a new physical mechanism for light-driven locomotion and provides design principles for scalable, untethered soft swimming robots, light-powered microtransport platforms, and adaptive micromotors.

Key words: self-sustained motion, boat, light-powered, liquid crystal elastomer (LCE), rotation

中图分类号:

. [J]. Applied Mathematics and Mechanics (English Edition), 2026, 47(5): 1065-1084.

Xueru WANG, Pengxin WANG, Junjie CHEN, Chuanyang HUANG, Kai LI. Light-powered self-propelling boat via self-rotating liquid crystal elastomer rod[J]. Applied Mathematics and Mechanics (English Edition), 2026, 47(5): 1065-1084.

图/表 15

Parameter	$R ¯$	$p ¯$	$α ¯$	$L ¯ s$	$β ¯ 1$	$β ¯ 2$
Value	0–0.2	0–0.1	0–0.3	0–20	0–1	0–1

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Parameter	Definition	Value	Unit
τ	Thermal relaxation time	0.3	s
T₀	Ambient temperature	300	K
m	Total mass of LCE rod and blade	0.015	kg
g	Gravitational acceleration	9.81	m/s²
R	Cross-sectional radius of LCE rod	0–0.004	m
p	Photothermal power	0–100	K/s
α	Thermal expansion coefficient	0–1×10^-3	K^-1
β₁	Damping coefficient of blade	0–2.5	Kg·m·s^-1
β₂	Damping coefficient of boat	0–2.5	Kg·m·s^-1
L_s	Support span	0–0.4	m
d	Length of blade	0.02	m