Fig. 3: Autonomous rolling and rotation of trefoil knotbots upon light irradiation.
From: Animating hydrogel knotbots with topology-invoked self-regulation
a Preparation of a right-handed trefoil knotbot. b Schematics of rolling and braid rotation of a trefoil knotbot. c Anticlockwise rotation and inward rolling of a trefoil knotbot under uniform light irradiation from the top. d, e Simulated stress distribution in a trefoil knotbot: (d) additional hoop stress with dynamic motion and (e) von Mises stress under uniform light irradiation. f Simulated results of polar angle ϕ and polar radius ρ of a specific cross-section, as well as the rolling angle γ of a specific particle, as functions of time under uniform light irradiation. g Variations of rotation angle θ and rolling angle γ of the trefoil knotbot as functions of time under uniform light with different intensities. h Variation of θ as a function of γ. The inset presents the ratio of rotation speed \(\dot{\theta }\) to rolling speed \(\dot{\gamma }\) of the knotbot. i Motion state diagram of the trefoil knotbot in water bath with different temperatures and under uniform light with different intensities. j, k Rolling and braid rotation of a right-handed trefoil knotbot upon clockwise (j) and anticlockwise (k) scanning light. l \(\dot{\theta }\) and \(\dot{\gamma }\) of the right-handed trefoil knotbot under clockwise and anticlockwise scanning light. m, n Simulations and schematics illustrating the kinematics of a right-handed trefoil knotbot with different motion speeds under clockwise (m) or anticlockwise (n) scanning of light. Data points are represented as mean ± s.d. (n ≥ 3).
