Optoelectronic Trajectory Reconfiguration and Directed Self-Assembly of Self-Propelling Electrically-Powered Active Particles

TL;DR

This paper demonstrates dynamic optoelectronic control of self-propelling Janus particles using patterned electrodes, enabling precise trajectory shaping and self-assembly into active structures for potential microrobotic applications.

Contribution

It introduces a novel optoelectronic system with DMD-patterned electrodes for real-time control and self-assembly of active particles, advancing autonomous microrobot manipulation.

Findings

Particles avoid crossing optical region edges, enabling trajectory constraint.

Multiple particles can be manipulated simultaneously to form stable structures.

The system supports closed-loop operation for programmable control.

Abstract

Self-propelling active particles are an exciting and interdisciplinary emerging area of research with projected biomedical and environmental applications. Due to their autonomous motion, control over these active particles that are free to travel along individual trajectories, is challenging. This work used optically patterned electrodes on a photoconductive substrate using a digital micromirror device (DMD) to dynamically control the region of movement of self-propelling particles (i.e. metallo-dielectric Janus particles (JPs)). This extends previous studies where only a passive micromotor was optoelectronically manipulated with a translocating optical pattern that illuminated the particle. In contrast, the current system used the optically patterned electrode merely to define the region within which the JPs moved autonomously. Interestingly, the JPs avoided crossing the optical region edge, which enables constraint of the area of motion and to dynamically shape the JP trajectory. Using the DMD system to simultaneously manipulate several JPs enabled to self-assemble the JPs into stable active structures (JPs ring) with precise control over the number of participating JPs and passive particles. Since the optoelectronic system is amenable to closed-loop operation using real-time image analysis, it enables exploitation of these active particles as active microrobots that can be operated in a programmable and parallelized manner