Quantitative volume determination of dispensed nanoliter droplets on the fly

Abstract

In this paper we present a sensor for non-contact monitoring of dispensed micro-droplets on the fly. In extension to our previous work [1], the sensor now allows for a direct, quantitative volume determination of single liquid droplets in the volume range from 20 to 100 nl. The improved electronic transducer enables to measure the droplet volume with an accuracy of ΔV ± 3 nl. The sensor signal provides a variety of information about the monitored droplet like for examples droplet velocity. This paper considers in particular the influence of the droplet velocity on the volume measurement. It turned out that the velocity effect can be fully compensated, if the signals are interpreted correctly.