Controllable and versatile self-motivated motion of a fiber on a hot surface

A light-powered self-rotating liquid crystal elastomer drill

“…Based on stimuli-responsive materials, including liquid crystal elastomers (LCEs) [ 28 ], ionic gels [ 29 , 30 ], hydrogels [ 31 , 32 ], etc., diverse self-oscillating systems have been widely developed recently. Especially, there have been numerous attempts to construct a large number of self-sustained motion patterns, such as vibration [ 33 ], bending [ 34 , 35 ], rolling [ [36] , [37] , [38] ], spinning [ 39 ], torsion [ 40 ], shuttling [ 41 ], self-oscillating auxetic metamaterials [ 42 ], self-floating [ 43 ] and self-curling [ 44 ], shrinking [ 45 ], swimming [ 46 ], swinging [ 16 , 47 ], buckling [ 48 , 49 ], jumping [ 50 , 51 ], rotation [ 52 , 53 ], chaos [ 54 ] and even synchronized motion of coupled self-oscillators [ 55 ]. In these self-oscillating systems, some special mechanisms are generally required for absorbing energy from the external environment to compensate for the dissipation consumed by the system damping [ 1 ].…”

Self-Sustained Oscillation of Electrothermally Responsive Liquid Crystal Elastomer Film in Steady-State Circuits

“…A rich variety of Self-excited oscillation systems constructed based on active materials have been recently reported, such as hydrogels [20,21], dielectric elastomers, ionic gels [22,23], liquid crystal elastomers (LCEs) [24][25][26][27][28][29] and temperature-sensitive polymers [30][31][32][33]. At the same time, researchers have proposed and constructed different Self-excited oscillation patterns based on various types of active materials, such as bending [30][31][32], flexing, twisting [33,34], stretching and contracting [35], rolling [36], swimming, oscillating, vibrating [37][38][39], jumping [40][41][42], rotating [43], turning outward or reversing, and even the synchronized motion of several coupled Self-oscillators. Owing to the damping effect of systems, Self-excited oscillation consumes energy during motion, so it usually originates from nonlinear feedback mechanisms that compensate for the damping consumption of a system through energy input [44][45][46], such as the Self-shadowing mechanism [36,47], the coupling mechanism of chemical reaction and large deformation [22], and the coupling motion mechanism of air expansion and liquid column [48,49].…”

Heat-Driven Synchronization in Coupled Liquid Crystal Elastomer Spring Self-Oscillators

“…These systems can be adjusted and controlled by tuning internal parameters and coupling methods. Additionally, self-oscillating systems exhibit great flexibility capable of displaying various oscillatory behaviors such as periodic oscillations [ 8 , 9 ] and chaotic oscillations [ 10 , 11 , 12 ]. Various feedback mechanisms have been suggested to counteract energy loss attributed to damping dissipation, including the coupling of chemical reactions and large deformations [ 13 , 14 , 15 ], as well as the self-shading mechanism [ 16 ].…”

“…Through ongoing research and development, scientists continue to discover new active materials with unique properties and enhanced performance, such as dielectric elastomers [ 25 ], hydrogels [ 26 , 27 ], ionic gels [ 13 ], thermal response polymers [ 28 ] and liquid crystal elastomer (LCE) [ 29 , 30 , 31 ]. These active substances produce different responses when stimulated by light [ 7 ], heat [ 9 ], electricity [ 32 ] and magnetism [ 33 ], and a variety of self-sustained motion modes have been established according to this property, for example, torsion [ 34 , 35 ], vibration [ 6 , 36 , 37 ], bending [ 38 , 39 , 40 , 41 , 42 ], swing [ 43 ], rolling [ 44 ], oscillating [ 45 ], jumping [ 46 , 47 ], rotation [ 48 ], buckling [ 49 , 50 ], twisting [ 51 ], stretching [ 52 ], eversion or inversion [ 53 ] and other movements. LCE, a unique material, possesses a hybrid nature that combines the characteristics of both liquid crystals and elastomers, which constitutes a polymer network structure resulting from the cross-linking of liquid crystal monomer molecules.…”