Advanced Characterisation of a Sensor System for Droplet-Based Microfluidics

Droplet-based microfluidics show a large potential for lab-on-chip applications and new data transmission scenarios. Microfluidic chips contain channels in the submillimeter range allowing for flow of droplets. In a previous contribution, a new sensor design for droplet size and colour detection, consisting of an infrared and a colour sensor, was presented and a first proof-of-concept was shown. In this work, an in-depth analysis of both concepts is presented. In particular, we show that a high precision can be achieved when using the sensor to measure droplet sizes while using video processing software as reference. Furthermore, a colour alphabet consisting of 126 individual values is transmitted and detected using a machine learning model. The high specificity of achieved colour measurement allows both for colour coded data transmission scenarios and the analysis of colour reagents in lab-on-chip applications.