Fig. 4. Shape transformation and deformation locking of a multifunctional artificial muscle.

(A) Shape transformation and deformation locking of a multifunctional artificial muscle under the irradiating power of 1.2 W. Scale bars, 10 mm. (B) Repeatability of the multifunctional artificial muscle under the irradiating power of 1.3 W. (C) Actuating stress of the multifunctional artificial muscle and PDA-coated LCE-based tubular actuator under the irradiating power of 1.2 W. The laser was applied on the multifunctional artificial muscle and PDA-coated LCE-based tubular actuator at 21 and 92 s, respectively. (D) The highest temperature on the LCE surface as a function of time under the NIR laser irradiation of 1.6 W. Inset: Comparison of deformation locking of multifunctional artificial muscle with three different melting points (T₁, T₂, and T₃) and their law of variation for bending angle over time. (E) Bending stiffness and output force of the multifunctional artificial muscle and PDA-coated LCE-based tubular actuator. Inset: Schematic showing the test method of bending stiffness. (F) Time-lapse photographs of the pick-and-place operation of the multifunctional artificial muscle under the upward and downward bending deformations and transient laser irradiation from both directions. Scale bars, 10 mm. Laser power: 2.0 W. The weight of the multifunctional artificial muscle was 0.87 g, and the weight being lifted was 100 g.