Dotette: Programmable, high-precision, plug-and-play droplet pipetting.

Manual micropipettes are the most heavily used liquid handling devices in biological and chemical laboratories; however, they suffer from low precision for volumes under 1 µl and inevitable human errors. For a manual device, the human errors introduced pose potential risks of failed experiments, inaccurate results, and financial costs. Meanwhile, low precision under 1 µl can cause severe quantification errors and high heterogeneity of outcomes, becoming a bottleneck of reaction miniaturization for quantitative research in biochemical labs. Here, we report Dotette, a programmable, plug-and-play microfluidic pipetting device based on nanoliter liquid printing. With automated control, protocols designed on computers can be directly downloaded into Dotette, enabling programmable operation processes. Utilizing continuous nanoliter droplet dispensing, the precision of the volume control has been successfully improved from traditional 20%-50% to less than 5% in the range of 100 nl to 1000 nl. Such a highly automated, plug-and-play add-on to existing pipetting devices not only improves precise quantification in low-volume liquid handling and reduces chemical consumptions but also facilitates and automates a variety of biochemical and biological operations.