Compact Live‐Cell Lensless Imaging Scheme via Rotating Mask

ABSTRACT Lensless imaging is a cost‐effective, high‐throughput approach to optical microscopy, widely used in biomedical research. However, high‐performance live‐cell lensless imaging often relies on redundant sample acquisition and strong prior assumptions, limiting system compactness and versatility. To address this challenge, we propose Mask‐Rotating Static Encoded Lensless (MaRSEL) microscopy, a framework for long‐term live‐cell imaging. By rotating a static, invariant mask at multiple angles and integrating an efficient calibration and reconstruction algorithm, MaRSEL achieves high‐fidelity complex‐amplitude imaging without high‐precision motion control. The mask rotates around its normal axis while the sample remains stationary, preserving cellular physiology and ensuring stable regions of interest during acquisition. Experiments on various biological specimens demonstrate ∼1 µm resolution within a 2 mm‐radius circular field of view. Moreover, MaRSEL enables over 130 min of continuous live imaging of cultured endothelial cells, supporting quantitative analyses including cell segmentation, counting, and tracking.