Fig. 1

Under a steady line illumination, the oscillator exhibits self-oscillation. Using a rope-rod bistable structure and a hysteretic occluder, self-oscillation is realized via hysteretic optical occlusion, eliminating the need for LCE’s rapid response to excitation in traditional systems (color online)"

Table 1

Self-oscillation period with diverse light powers"

Fig. 2

Schematics of the LCE-based bistable self-oscillator: (a) key components of the system, including the LCE fiber, spring, rope, rod, and hysteretic occluder; (b) assembled bistable photo-oscillator, showing the geometric configuration and coordinate system (the origin O, moving point A, and key dimensions L1, Ls, Lc, Lb, Lsp, and Lr); (c)–(h) sequential states of one full oscillation cycle under steady illumination, where red arrows indicate the order of state transitions, in which (c) shows the right-inclined initial state, with the rod and occluder resting on the right; (d) shows the right-inclined central state, with Point A from the right to central axis; (e) shows the right-inclined critical state, with the rod from the right to the central axis; (f) shows the left-inclined critical state, with the rod from the left to the central axis; (g) shows the left-inclined central state, with Point A from the left to the central axis; (h) shows the left-inclined initial state, with the rod and occluder resting on the left. Under steady illumination, the hysteretic occluder enables the fiber to fully contract and relax at the critical state, thereby completing the state transition and generating self-oscillation (color online)"

Fig. 3

Two motion regimes of the LCE-based self-oscillator: steady regime and self-oscillatory regime, where the system parameters are k¯=0.3, C¯0=0.25, H¯=0.35, L¯r=0.3, and L¯c=0.11: (a) α versus t¯ with L¯b=0.1 and Q¯=0.8; (b) α versus t¯ with L¯b=0.08 and Q¯=1.1; (c) α versus t¯ with L¯b=0.1 and Q¯=1.1; (d) ε versus t¯ with L¯b=0.1 and Q¯=0.8; (e) ε versus t¯ with L¯b=0.08 and Q¯=1.1; (f) ε versus t¯ with L¯b=0.1 and Q¯=1.1 (color online)"

Fig. 4

Bistable mechanism of the self-oscillator, where the system parameters are k¯=0.3, Q¯=1.1, C¯0=0.25, H¯=0.35, L¯b=0.11, L¯r=0.3, and L¯c=0.11: (a) x¯ versus t¯; (b) α versus t¯; (c) geometric hysteresis loop. When the critical displacement is reached at Point A, the unique bistable structure causes a sudden change in the rod’s tilt angle, resulting in a state transition of the self-oscillator (color online)"

Fig. 5

Effects of parameters on the critical strain, where the base parameters are Q¯=1.1, C¯0=0.25, H¯=0.35, k¯=0.3, L¯b=0.11, L¯c=0.11, and L¯r=0.3: (a) ε versus k¯; (b) ε versus L¯b; (c) ε versus L¯c; (d) ε versus L¯r. εright is the critical strain for right-to-left transition under light conditions, while εleft is the critical strain for left-to-right transition under dark conditions. Self-excited oscillation occurs when the light-driven contraction strain exceeds εright, and the strain recovery under dark conditions falls below εleft (color online)"

Table 2

Geometric configuration constraints for the self-oscillator"

Fig. 6

Effects of the photothermal power Q¯ and contraction coefficient C¯0 on Δt¯1, where the fixed parameters are k¯=0.3, H¯=0.35, L¯r=0.3, L¯b=0.11, and L¯c=0.11: (a) ε versus t¯ under C¯0=0.25 and Q¯=1.1, 1.2, 1.3; (b) Δt¯1 versus Q¯; (c) ε versus t¯ under Q¯=1.1 and C¯0=0.25, 0.30, 0.35; (d) Δt¯1 versus C¯0 (color online)"

Fig. 7

Effects of the photothermal power Q¯ and contraction coefficient C¯0 on Δt¯3, where the fixed parameters are k¯=0.3, H¯=0.35, L¯r=0.3, L¯b=0.11, and L¯c=0.11: (a) ε versus t¯ for Q¯=1.1, 1.2, 1.3 and C¯0=0.25; (b) Δt¯3 versus Q¯; (c) ε versus t¯ for Q¯=1.1 and C¯0=0.25, 0.30, 0.35; (d) Δt¯3 versus C¯0 (color online)"

Fig. 8

Effects of Q¯ and C¯0 on Δt¯p, where the fixed parameters are H¯=0.35, L¯r=0.3, k¯=0.3, L¯b=0.11, and L¯c=0.11: (a) α versus t¯ under C¯0=0.25 and Q¯=1.1, 1.2, 1.3; (b) ε versus t¯ under C¯0=0.25 and Q¯=1.1, 1.2, 1.3; (c) Δt¯p versus Q¯; (d) α versus t¯ under Q¯=1.1 and C¯0=0.25, 0.30, 0.35; (e) ε versus t¯ under Q¯=1.1 and C¯0=0.25, 0.30, 0.35; (f) Δt¯p versus C¯0 (color online)"

Fig. 9

Theoretical and experimental frequencies of the self-oscillator under varying light powers (color online)"