Faceted Photocatalytic Microswimmers for Adaptive Navigation and Cargo Transport via Structured Illumination.

Abstract

Precise navigation of photocatalytic microswimmers typically requires external fields, physical confinement, chemical gradients, or feedback control, limiting their operation in dynamically changing environments. Here, light-programmable faceted BiVO4 microswimmers are introduced, where structured illumination provides both the energy for propulsion and the spatial information required for navigation. While uniform illumination activates self-propulsion without directional guidance, patterned illumination defines light-dark interfaces that the microswimmers autonomously follow through continuous reorientation. Fluorescence mapping, EPR spectroscopy, tracer-particle experiments, facet-distribution controls, and numerical simulations support a mechanism in which partial illumination creates asymmetric photocatalytic activity, generating local chemical gradients and associated flow fields around the particle. These local imbalances allow microswimmers to remain coupled to projected boundaries, adapt to static and dynamically reconfigured geometries, and follow independently programmed trajectories within the same field of view. The same strategy enables light-controlled cargo capture, transport, and release along confined and serpentine pathways. Overall, this work establishes an all-optical strategy to activate, direct, and reprogram photocatalytic microswimmer motion, enabling adaptive navigation and cargo transport along complex pathways.

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