Optical Tweezers with Integrated Multiplane Microscopy (OpTIMuM): a new tool for 3D microrheology

Abstract We introduce a novel 3D microrheology system that combines for the first time Optical Tweezers with Integrated Multiplane Microscopy (OpTIMuM). The allows tracking of an optically trapped bead, ~ 20 nm accuracy along optical axis. This is achieved without need high precision z-stage, separate calibration sample, nor priori knowledge either bead size or properties suspending medium. Instead, we have developed simple yet effective in situ spatial method using image sharpness and exploiting fact at multiple planes simultaneously. These features make OpTIMuM ideal measurements, corroborate effectiveness this tool by measuring viscosity water three dimensions,