Application and development of optical-based viscosity measurement technology

Viscosity, as a crucial property of liquids, plays a vital role in various fields, including food, chemical, pharmaceutical, personal care, and biomedicine. Therefore, it is of great significance to develop methods that can accurately measure the viscosity of liquids in various environments. To this end, researchers have developed a variety of viscosity measurement techniques. In view of the complexity of viscosity measurement, viscosity measurement in many cases depends on optical technology. Optical-based viscosity measurement technology has demonstrated excellent performance at both macro and micro levels because of its suitability for low sample volumes and the advantages of non-contact measurement. Besides, it can be easily combined with other technologies and is suitable for a wide range of application scenarios. In this paper, we reclassify the optical technology used in the field of viscosity measurement, summarize the latest developments of optical technology in viscosity measurement, and discuss its future development direction. This review aims to assist researchers in mastering the latest developments in optical viscosity measurement techniques and to encourage experts in related fields to utilize and develop these techniques to address specific engineering requirements.