A robust and scalable active-matrix driven digital microfluidic platform based on printed-circuit board technology

Abstract

Two-dimensional digital microfluidic platforms, on which droplets are actuated by electrowetting on dielectrics, have merits such as dynamic reconfigurability and ease for automation. However, concerns for digital microfluidic platforms based...

Viral Generation, Packaging, and Transduction on a Digital Microfluidic Platform

“…As depicted in Figure , this “proof-of-principle” method was carried out in a 12-plex format (through the use of “highway tracks”), and we propose that this will be straightforward to expand this technique to much higher levels of multiplexing given the electrode and bussing techniques presented here (and particularly with recent reports of active matrix methods , ). We constructed lentiviral plasmids (Figure S11; available on Addgene) to perform lentiviral packaging, production, and transduction for knockdown (RNAi) and knockout (CRISPR) assays and we obtained very similar gene expression profiles compared to benchtop assays, with shorter time scales (days vs weeks) to obtain viral titers at sufficient levels, 100-fold savings in volumes to save precious lentiviral samples, and using minimal number of cells (∼1000 to 3000 cells).…”

“…Although downstream gene editing analysis of CRISPR knockouts from microfluidic devices have been shown previously [45, 57b, 85] , this is the first demonstration showing integration of lentiviral packaging, generation, and transduction on a microfluidic device followed by downstream gene editing analysis (off-device). As depicted in Figure 3.1, this method was carried out in a 12-plex format (through the use of "highway tracks") and we propose that this will be straightforward to expand this technique to much higher levels of multiplexing given the electrode and bussing techniques presented here (and particularly with recent reports of active matrix methods [65,86] ). In addition, through the use of DMF for lentiviral packaging, production, and transduction, it is possible to obtain very similar gene expression profiles (via RNAi and reduction in volumes to save precious lentiviral samples.…”

Vertical Addressing of 1‐Plane Electrodes for Digital Microfluidics

“…Specifically, VAPE-DMF distributes the functions of the bottom plate between two independent subsystems (the cover and the sub-substrate, Figure 1d), allowing the user to take advantage of specialized manufacturing technologies and technical solutions for each system. Specifically, when choosing the sub-substrate, the fabricator can simply use standard PCBs, which are inexpensive and accessible, or any other suitable method [10][11][12][13][14] to form vertically addressing connections. Likewise, in forming the cover, the fabricator can choose techniques that allow for the formation of closely spaced driving electrodes with no "trenches" between them.…”

“…Multilayer photolithography is an alternative to PCBs that can satisfy all the necessary technological parameters indicated above for vertical addressing devices. For example, the multinational display company, Sharp Corporation [10,11] (and others [12] ), has developed methods relying on thin film transistors (TFTs) that allow the formation of large arrays of DMF electrodes. However (at the moment), Sharp is not selling their devices to outside users, and it is likely that the cost of such systems will make them unjustifiable for use as a daily (disposable) tool in a biology or chemistry laboratory.…”

Integrating machine learning and digital microfluidics for screening experimental conditions

“…The low electrode density only allows for tens of reactions to be performed in parallel. There are physical solutions to increase the electrode density (and to increase reactions in parallel): vertical addressing techniques, [26][27][28][29] inkjet-printing techniques, 30 and three dimensional stacking of substrates; 31 however, there continues to be limits on the number of reactions or conditions that can be handled on the platform due to unreliable droplet movement, μL-volume requirements, and evaporation or biofouling challenges.…”