Digital microfluidics is a droplet- based liquid handling technology with no tubes, channels, pumps or valves. Instead, discrete droplets are manipulated electrically through the use of electrodes to control the movement of each droplet independently.
Through the use of the electrowetting effect, droplets are precisely manipulated within a fully-contained cartridge. Electrowetting describes the use of applied voltage to reduce the hydrophobicity of a surface. Aqueous droplets naturally "bead-up" on a hydrophobic surface, but voltage applied between a droplet and an insulated electrode can cause the droplet to spread on the surface as illustrated below.
The application of electrical signals to an array of electrodes can be used to control the size, position and movement of each droplet. Droplets are transferred between adjacent electrodes by removing voltage from one electrode and applying it to the next one. The schematic cross-section below illustrates the structure of a digital microfluidic cartridge.
The same processes can be used to dispense, merge or split droplets using electrical signals. Sequences of basic operations can be combined to create complex liquid handling protocols where hundreds of droplets can be simultaneously and independently manipulated.
This digital microfluidic technology permits precise delivery and mixing of sub-microliter volumes not achievable with traditional robotic liquid handlers. The nano-scale capability of the platform enables higher concentrations of reactants and improved reaction kinetics. On-cartridge purification and targeted reagent delivery enable integration of several enzymatic steps, shorter elapsed times and complete walk-away operation. The fully self-contained, disposable cartridge reduces the risk of environmental and carryover contamination. Optimization of NuGEN reagents for use on the Mondrian SP System will enable flexibility for multiple applications, and ensure the highest level of performance and reproducibility with minimal sample input.
To learn more about digital microfluidics, follow this link to Microfluid Nanofluid (2007) 3:245-281
Learn more about the Mondrian SP System here
The Mondrian SP Workstation and SP Cartridges were developed and manufactured for NuGEN by Advanced Liquid Logic®