Mimicking Life: Autonomous Oscillating Artificial Cilia Driven by Chemical Power

Cilia are filamentous organelles that carry out functions critical for life, including fluid transport and locomotion. Given their importance, artificial cilia have been developed to mimic natural ones. While significant, current designs are largely nonautonomous, primarily powered by external fields and stimuli, unlike biological cilia. The design, synthesis, and optical tracking of individually autonomous, chemically powered artificial cilia that undergo biomimetic, oscillatory motion are reported. These soft hydrogel structures are actuated by an oscillatory chemical reaction without external stimuli. They display 3D, elliptical beat patterns and operate in the low Reynolds number regime. The magnitude and direction of deflection arise from the vector sum of internal chemical waves. Cilium trajectories show chemotactic behavior, resembling biological systems, influenced by local reactant and product concentrations. This autonomous system offers a platform for the testing of mechanistic models for the emergence of collective behaviors and advancing the design of autonomous soft robotics.