Fig. 3.

Complex programmed inflation trajectory of 3D soft bodies and finite element simulation. a Elongating cylindrical actuator (at θ = 90°) with an additional STAUD-prepreg wrapped around at θ = 0° or 45°. The addition of a STAUD-prepreg at θ = 0° immobilizes the actuator, while one at θ = 45° gives rise to rotational motion without transverse strain $\left({\epsilon }_t\right)$. Scale bar: 25 mm. b–d Bending motion of a cylindrical actuator due to a segmented STAUD-prepreg patch. b Increasing the areal coverage of the patch decreases the bending angle at a given pressure. c Adhering a patch at θ = 45° elicits a mixed motion of bending and twisting. d Two-localized patches with increasing patch dimension along the actuator length leads to a higher bending curvature. Scale bar: 25 mm. e, f Finite element (FE) analysis results using ABAQUS on cylindrical actuators. e Bending angle as a function of input pressure and a patch’s areal coverage, as gathered from the simulation. f Two-localized patches with different fiber angles (at θ = 0° and 45°). g A slender cylindrical actuator mimicking the motion of cephalopod tentacles. FE simulation of the actuator with particular patch pattern and dimensions matches with the experiment. Scale bar: 50 mm