Light-induced selective speed alteration of magnetically rolled semiconductor particles.

ABSTRACT: Microrobot teams or swarms are promising candidates for many applications, such as micromanipulation, microsurgery, or targeted drug delivery. However, attaining individual control of the microrobots, which is a critical component to many of their applications, remains a significant technical challenge. We introduce a method to control the magnetic rolling speed of hematite semiconductor particles using localized UV light, attributed to light-induced changes in particle-substrate friction. Simulations and theoretical models support our experimental observations, showing how particle-substrate separation influences speed. Additionally, we demonstrate fixed patterning of microparticles via selective UV illumination at lower pH, demonstrating selective immobilization of microrobots, a conceptual step toward applications such as targeted drug delivery or patterned cell stimulation in future studies. Therefore, this work provides a novel approach for independent control of microrobot systems by modulating particle-substrate interactions with light.

SUBMITTER: Rivas DP 

PROVIDER: S-EPMC12856435 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature