Investigating Dynamic Reconfiguration of Colloidal Particle Assemblies

In recent years, the reconfigurability of microscopic particle assemblies through external stimuli has emerged as a groundbreaking technique in developing nanoscale devices and systems. This study explores the dynamic reconfiguration of polystyrene particle (10 μm) assemblies under the influence of light, leveraging the unique properties of light-responsive gold nanoparticles (15 nm). We demonstrate the controlled manipulation of particle crowds into predetermined shapes and patterns by employing a simple experimental setup that combines digital micromirror devices, high-intensity LED light, and imaging techniques. We projected patterns of different shapes (squares and triangles) and sizes. The assembled polystyrene particle crowd adapted to each shape, demonstrating the possibility of programmable self-assembly. We projected a rectangular pattern and reconfigured it into a curved shape for multiple cycles. The maximum number of cycles in which the crowd successfully reconfigured its shape was recorded. Our findings open new avenues for fabricating microscopic robots with potential applications in targeted drug delivery and cellular transport.