Abstract

Digital Microfluidics, Droplet Microfluidics, Centrifugal Microfluidics: Non-Contact Liquid Handling in the pL- and nL-Volume Range

Eckhard Nordhoff, Chief Scientific Officer, M2-Automation

Reducing costs of lab-on-a-chip-based devices involves miniaturization and pre-loading chips with reagents. For liquid handling steps involved, volumes are reduced from µL to nL and pL amounts. If, for instance, only 100 pL of an expensive reagent solution is required, only 1 µL is consumed for the production of 10,000 devices. This is best achieved with low volume non-contact dispensing of liquids either as individual droplets or as short jets.  It is now common practice for ink-jet printers to deposit materials into LOAC devices. High quality depositions, however, require that the printer, printer driver, composition of the buffer ink and properties of the surfaces have all been optimized for these tasks. In LOAC projects, a wide range of biological or chemical solutions must be dispensed. Surfaces are most often polymer-modified plastics or glass. Obvious challenges are to provide printing tools that can handle the range of solution properties, and to optimize liquid and deposition surface properties. Our presentation will discuss such printing tools, how they work and how they are used.  In particular, we will focus on their implementation in the automated production of lab-on-a-chip-based devices. Recommendations for surface design and liquid properties will also be presented.