Autosizing, Closed-Loop Drop Generator Using Morphometric Image Feedback

The ability to precisely choose a drop volume is highly desirable for biological assays, chemical reactions, particle manufacturing, and other applications. This paper presents the first drop generator which auto-tunes plug length to a user-defined value. It uses a real-time feedback loop which measures plug length and accordingly tunes a pressuredriven flow focusing junction. The drop generator achieves a 4-fold dynamic tuning range and <10 sec tuning time. Feedback-controlled drop generators can be useful for workflows in where volume tolerances must be maintained over long periods of time, or where multiple metered volumes must be provided by a single device.