A multifunctional microfluidic platform combining on-demand aqueous-phase droplet generation, multi-droplet storage, and controlled merging of droplets selected from a storage library in a single integrated microfluidic device is described.
The Ratcheting Electrophoresis Microchip (REM) is a microfluidic device for electrophoretic separation of biomolecules such as DNA and proteins. By using thousands of electrodes along the length of a microchannel, the REM separates molecules using low applied voltages (∼1 V) in short times (< 1 minute). This paper describes the microfabriation of the REM and initial testing results. Parallel arrays of platinum electrodes are fabricated on a silicon chip with a pitch of 10 μm. Two types of channels are fabricated: silicon nitride channels fabricated on the chip and poly(dimelthylsiloxane) (PDMS) channels fabricated separately and attached to the chip. Initial testing shows partial success with the PDMS channels and promis ing results for the silicon nitride channels.
Rapid on-demand sacrificial printing techniques using suitable combinations of resin and sacrificial materials would be desirable to fabricate versatile and functional microfluidic devices with complex designs and chemical resistance.
We generate traveling surface acoustic waves with an interdigital transducer to create droplets on-demand; encapsulate single cells; lyse cells and immediately encapsulate their contents; and pico-inject new materials into existing droplets.