With the increasing demand of miniaturisation of medical devices and increased throughput, the concept of a lab-on-a-chip emerged and grew over the past 2 decades. In that context, the idea that liquid droplets could be used effectively as test tubes by confining within them analytes and reagents arose and digital microfluidics was born. The droplets can be transported in microchannels, reactions induced by mixing the reacting droplets, and with appropriate sensor the result of these reactions can be monitored and analysed...