Tunable SIM: Observation at varying spatiotemporal resolutions across the FOV

To date, imaging systems have generally been designed to provide an even spatiotemporal resolution across the field of view (FOV). However, this becomes a fundamental limitation when we aim to simultaneously observe varying dynamics at different parts of theFOV. In conventional imaging systems, to capture fast dynamics occurring at only a small portion of theFOV, the entire imaging system's sampling rate must be increased. This is a major problem if different parts of theFOVmust rather be imaged at high spatial resolutions beyond the diffraction limit and require a sacrifice in temporal resolution. To answer this unmet challenge, we propose tunable SIM, which enables adaptive modulation of spatiotemporally varying structured illumination across different parts of theFOV.Using tunable SIM, we exploit the varying and designable spatiotemporal resolution to demonstrate simultaneous measurements of subdiffraction-limited changes in the actin fine structure of U87MG-EGFP-CD9 cells and the fast viscous flowinducing these structural changes.