NEW CONCEPT
Implemented in Existing Machines
Our group is working on up-scaled microlfuidics to meet the real need of massive applications, such as high-througput screening of single molecules or single cell analyses. Starting from producing massive droplets at nanoliters or even femtoliters in capillary junctions of bio-machines under ultra-high pressure, we are managing to detect and sort the droplets running in capillary with the functions of machine. The massive droplets are holding single molecules or living cells, and the resultant devices will work as plugins of the machines. In these efforts, we will find a proper way for the microlfuidics to scale up to meet massive needs as the machines have done. We have demonstarted the first effort by setting up an capillary-based ddPCR system with a capillary cytometer. A second demonstrates that the positive droplet could be sorted with a sophisdicated cytomter, promising immediately for single molecule screening or even single cell analyse at the genomic level. Our research is generously supported by funding from the Chinese government and other foundations.
Research
DROPLET GENERATION, FISSION AND TRANSPORT IN NON-PDMS DEVICES
DROPLET FORMATION
Droplets results from comprehensive roles of interfacial instability of two immisible fluids, their pressures and temperatures, and surfactants in them. There is still a limited knowlege of their interactions, and they are essential for us to control well both frequencies and sizes of droplets on their formation in existing machines, as well as in research for more sensitive manipulation and data acquisitions.
DROPLET MANIPULATION
In an effort to capture molecules with tiny droplets, we have to set up systems to transport these droplets to desired sites precisely, such as where a PCR occurs. In the process of transportation, droplets are usually thermocycled in a prescribed way, and finally they might be sorted on demand. In these manipulations, the stability of droplets is one of key issues we have to be faced with. Their solutions will be found with chip-based models or models coupled with existing highly precise machines.
AUTOMATION WITH SOPHISTICATED SYSTEMS
With the available highly precise sequecing machines or cytometers, we are developing powerful microfluidic tools specific for identification and characterization of DNA/RNA in assays. Our major aim is at the high sensitivity as well as the full recovery of target molecules, which allows one to detect very rare molecules at high flow rates and to collect them in the end.