Size and Illumination Matters: Local Magnetic Actuation and Fluorescence Imaging for Microrobotics.

Combining local magnetic actuation with fluorescence imaging modalities promises to introduce significant advances in microrobotic-guided procedures. This review presents the advantages and challenges of this approach, emphasizing the need for careful design considerations to optimize performance and compatibility. Traditional microrobotic actuation systems rely on bulky electromagnets, which are unsuitable for clinical use due to high power requirements and limited operational workspace. In contrast, miniaturized electromagnets can be integrated into surgical instruments, offering low power consumption and high actuation forces at the target site. Fluorescence imaging modalities have been explored in microrobotics, showcasing spatiotemporal resolution and the capability to provide information from biological entities. However, limitations, such as shallow penetration depth and out-of-focus fluorescence, have motivated the development of advanced techniques such as two-photon microscopy. The potential of two-photon microscopy to overcome these limitations is highlighted, with supporting evidence from previous studies on rat tissue samples. Current challenges in optical penetration depth, temporal resolution, and field of view are also addressed in this review. While integrating miniaturized electromagnets with fluorescence imaging modalities holds the potential for microrobotic-guided procedures, ongoing research and technological advancements are essential to translating this approach into clinical practice.