Optofluidic phase-shifting digital holographic microscopy for quantitative measurement of microfluidic diffusion dynamics

Abstract

In this work, an integrated optofluidic phase-shifting element, along with an image processing algorithm, was proposed to enable quantitative analysis for microfluidic applications using a digital holographic microscopic configuration. The advantages of the proposed system lie in its compactness, that the phase-shifting element can be simultaneously fabricated with other microfluidic functional components on a single chip, its robustness to resist environmental vibrations as no mechanical movement is involved for phase-shifting, and its capability of capturing transient events of fluid dynamics for quantitative measurement. The performance of the proposed system was validated with quantitatively label-free monitoring of concentration gradients under various conditions in microchannels.