Figure 4.

(a) Schematic illustration and posture of the magnetic actuation of fish-like locomotion under an oscillating field (B_o) and a uniform field (B_u). 1–5 and 1’ represent posture of MMR at different time points. Scale bars, 1 mm. Reproduced with permission [55]. Copyright 2022. The Authors, some rights reserved, exclusive licensee American Association for the Advancement of Science. (b) Schematics of the LarvaBot with a variety of reprogrammable coupled gaits, including the biomimetic swimming gait and the decoupling of basic motion. Reproduced with permission [72]. Copyright 2022, Wiley-VCH. (c) Illustration and experimental images of a robot at the end of each heating and cooling half-cycle over three consecutive cycles. Reproduced with permission [73]. Copyright 2022. The Authors, some rights reserved, exclusive licensee American Association for the Advancement of Science. (d) Photographic images of forward moving and steering soft aquabots with a sculling motion. Scale bar, 3 cm. Reproduced with permission [19]. Copyright 2022. The Authors, some rights reserved, exclusive licensee American Association for the Advancement of Science. (e) Sequential snapshots of a swimmer while shining constant light. Input power was 450 mW. Reproduced with permission [75]. Copyright 2019, The Authors, some rights reserved, exclusive licensee American Association for the Advancement of Science. (f) Harpoon device. From I to IV: harpoon being lowered over opening, harpoon head resting on opening and unable to spear object, once fueled, head contracts and passes through opening, harpoon being lifted and taking object with it after re-expansion of head. Carried out in 5.0 mm MOPS with 5.0 mm TBA fuel. Reproduced with permission [77]. Copyright 2023, Wiley-VCH.