We proposed a novel algorithm to dispense solutes as 4 µL droplets with a common concentration difference between neighboring droplets. Using this algorithm, we performed vertical contact-separation processes (VCSPs) that successfully dispensed droplets with a common solute concentration difference with high and stable resolution. Our algorithm can be applied to VCSPs of a large number of droplets and multiple solutes. Thus, using our algorithm, we can increase the throughput of biochemical assays with linearly scaled concentrations.
Bono et al. (Sun,) studied this question.