Rotational Locomotion of an Active Gel Driven by Internal Chemical Signals

Abstract

Chemical waves arising from coupled reaction and transport can serve as biomimetic "nerve signals" to study the underlying origin and regulation of active locomotion. During wave propagation in more than one spatial dimension, the propagation direction of spiral and pulse waves in a nanogel-based PAAm self-oscillating gel, i.e., the orientation of the driving force, may deviate from the normal direction to the wave fronts. Alternating forward and backward retrograde wave locomotion along the normal and tangential kinematic vectors with a phase difference leads to a curved path, i.e., rotational locomotion. This work indicates that appendages in an organism are not required for this type of locomotion. This locomotion mechanism reveals a general principle underlying the dynamical origin of biological helical locomotion and also suggests design approaches for complex locomotion of soft robots and smart materials.

Anisotropically Deforming Sandwich-Type Self-Oscillating Gels: A Hierarchical Model Platform of Cardiac Tissue

“…When the introduced metal catalyst undergoes repetitive redox state change during the BZ reaction, the gel network can experience periodical hydrophilicity changes, leading to water in/outflux and volume oscillations . The elasticity of the material itself and the unique self-oscillatory behaviors have led to the birth of various gel actuators and models that mimic diverse life-like mechanical movements. − …”

3D Printing Bio‐Inspired Micro Soft Robot with Programming Magnetic Elastic Composites

“…Chemical reaction drive also affects the motion efficiency of soft robots due to its low reaction efficiency and complex reaction process. [37][38][39] Control systems for gas-liquid phase change robots are relatively complex because the control of gas-liquid phase change requires precise temperature, pressure, and flow control. [40][41][42] In contrast, magnetic actuation enables simple wireless non-contact control and has a unique advantage in controlling soft robots inside enclosed spaces.…”

Transitions of Collective Motions Driven by Phase Resetting

“…BZ gels have been used to design a variety of biomimetic phenomena, such as autonomous reciprocating migration, [30] phototaxis, [31] and rotational locomotion. [32] In addition to the catalyst oscillations, the reaction exhibits periodic variations in the concentration of an activator species, HBrO 2 , [33] which is dispersed into the solution and serves as the communication vector between discrete gel segments. This behavior can be exploited to generate complex behavior, such as the rotation of a group of gels.…”

“…In the BZ gel system, the concentration of oxidized metal ions oscillates periodically, resulting in alternating expansion and deswelling of the gel, which leads to gel locomotion. BZ gels have been used to design a variety of biomimetic phenomena, such as autonomous reciprocating migration, [30] phototaxis, [31] and rotational locomotion [32] . In addition to the catalyst oscillations, the reaction exhibits periodic variations in the concentration of an activator species, HBrO 2 , [33] which is dispersed into the solution and serves as the communication vector between discrete gel segments.…”