3D Robotic Control of Micro-Scale Optical Swarms at an Interface
Nicholas Carlisle, Volker Nock, Martin Williams, Catherine Whitby, Jack L Y Chen, Ebubekir Avci
AI summary
Problem
Existing control methods for optical force-induced microswarms are largely limited to 2D manipulation or static axial adjustments, hindering their use in complex micromanufacturing tasks.
Approach
The authors systematically test dynamic axial displacement and XY-plane locomotion using holographic optical traps at a glass-liquid interface, implementing a PID feedback loop to autonomously regulate swarm size during motion.
Key results
- Dynamic axial displacement effectively controls assembly morphology and particle spacing
- Glass-liquid interfaces provide significantly higher stability and fewer particle ejections than air-liquid interfaces
- A PID algorithm successfully enables autonomous axial control during open-loop locomotion
- Swarms are autonomously guided through simulated micro-constrictions by modulating trap height
Why it matters
Provides foundational 3D control techniques for scalable, autonomous micromanufacturing and targeted micro-tool assembly.
Abstract
Optical force-induced assembly is a promising yet scarcely explored approach for developing functional tools and objects at the microscale, with a wide range of potential applica- tions. Our previous work was the first to investigate the manipula- tion of these assemblies in the XY plane. Here, we expand on these techniques by systematically exploring optical trap manipulation with the addition of Z-axis control. Manipulation of the Z-axis is referred to as axial displacement and is a viable approach for actively manipulating the assembly morphology. Experiments are conducted for the first time to explore and detail the response of the assembly during active 3D trap manipulation, informing the development of an autonomous control algorithm over the 2D area of the assembly during motion. This control presents techniques to increase assembly stability or alter the area of the assembly for tasks such as passing through constrictions. This work aims to develop the control techniques required to create a unique micromanufacturing approach inspired by the Kilobot thousand-robot swarm.