Monitoring of droplet growth with nano-litre resolution for liquid flow rate, level or surface tension measurement

The determination of small liquid volumes and their changes over a period of time is a measuring problem with increasing importance considering the growing market of micro-systems. In this paper, experimental investigations are described which aim to observe the growth of droplets at the end of a micro-channel, such as a cannula or capillary. The main focus of the work lies on the calculation of flow rates below 1 ml/h. Furthermore, the potential of the measuring equipment for liquid level and surface tension measurement is described.