Programmable Assembly and Cooperative Manipulation of Heterogeneous Microspheres Via Optoelectronic Tweezers

Abstract

The programmable assembly and actuation of micro- and nanostructures remain key challenges in the development of micro-robotics. This work presents a programmable assembly and cooperative actuation strategy for heterogeneous microspheres based on optoelectronic tweezers (OET). By employing Ag-PS microspheres as actuators and PS microspheres as payloads, we constructed stable “actuator–payload” units and investigated their frequency response and dynamic characteristics. The proposed method enables controlled assembly into core–satellite and satellite–core configurations with tunable coordination angles. Furthermore, the cooperative effect of the dual actuating units was revealed, enabling the composite system to maintain a continuous and precise circular trajectory following a ring-shaped light pattern. In addition, the modular assembly strategy was used to construct chain-like structures exceeding 172 μm in length, thereby confirming the approach's scalability. This work expands the application of OET from particle transport to modular microstructure construction and multi-actuator cooperative control, offering new opportunities for designing microbotic systems and their biomedical applications.