From Wikipedia et al.

Microfluidics Research Groups (Omics International Link Page based on Wikipedia article:  https://en.wikipedia.org/wiki/List_of_microfluidics_research_groups)

List of Microfluidics Research Groups - North America

List of Microfluidics Research Groups - Asia and Australia

List of Microfluidics Companies (from FluidicMEMS)

Experts in Microfluidic Analytical Techniques (From biomedexperts.com)

Chemical and Life Science Applications

The Whitesides Research Group (Prof. George M. Whitesides, Chemistry & Chemical Biology, Harvard Univ.)
Ismagilov Group (Prof. Rustem F. Ismagilov, Department of Chemistry, CALTECH)
Mathies Research Group (Prof. Richard Mathies, University of California, Berkeley) 
Chiu Lab (Prof. Daniel T. Chiu, Department of Chemistry, University of Washington)
Biomicrofluidics System Group (Dr. Jianhua Qin, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, China)
Wheeler Microfluidics Laboratory (Prof. Aaron Wheeler, Dept. of Chemistry, University of Toronto)
Micro and Nanobioengineering Group (Prof. David Juncker, Biomedical Engineering Department, McGill University)
Soh Laboratory (Prof. H. Tom Soh, Department of Materials, Department of Mechanical Engineering, University of California, Santa Barbara) 
Bioinstrumentation for Quantitative Biology & Medicine (Prof. Amy E. Herr, Department of Bioengineering, University of California, Berkeley)
Lµ Fluidics Group, Microsystems for the Life Sciences (Prof. Hang Lu, School of Chemical & Biomolecular Engineering Georgia Institute of Technology)  

Physical and Life Science Applications

Prof. Robert Austin (Physics Department, Princeton University)
Complex Fluids Group (Prof. Howard A. Stone, Dept. Mechanical and Aerospace Engineering, Princeton University)
Stephen Quake's Group at Stanford University
Prof. Luke P. Lee (Director of the Biomedical Institute for Global Health Research & Technology, National University of Singapore)
Microtechnology Medicine Biology Lab (Prof. David J. Beebe, University of Wisconsin, Madison)
BIOS-The lab on a chip Group (Prof.dr.ir. Albert van den Berg, University of Twente, The Netherlands)
The Takayama Lab (Prof. Shuichi Takayama, Wallace H. Coulter Dept. of Biomedical Engineering, Georgia Institute of Technology and Emory University)
Biomolecular Microsystems and Nanotransducers (Prof. Abraham Lee, Biomedical Engineering Department, University of California, Irvine)
Stanford Microfluidics Laboratory (Prof. Juan G. Santiago, Department of Mechanical Engineering, Stanford University)
Prof. Joel Voldman (Massachusetts Institute of Technology)
RLE  Micro - Nanofluidic BioMEMS Group (Prof. Jongyoon Han, Massachusetts Institute of Technology)
Duke Acoustofluidics Lab (Prof. Tony Jun Huang, Dept. of Mechanical Engineering and Materials Science, Duke University)

NEMS, MEMS, and BioMEMS Applications

Craighead Research Group (Prof. Harold G. Craighead, School of Applied and Engineering Physics, Cornell University)
MicroSystems and BioMEMS (Prof. Chong H. Ahn, Department of Electrical Engineering / Biomedical Engineering, University of Cincinnati)
Micro Nano Manufacturing Laboratory (Prof. Chang-Jin "CJ" Kim, University of California, Los Angeles)
UCLA Micro Systems Laboratories (Prof. Chih-Ming Ho)
Integrated Photonics Lab (Prof. Ming C. Wu  (Electrical Engineering and Computer Sciences Department, University of California, Berkeley)
Micromachining Lab (Prof. Yu-Chong Tai, CALTECH)

The Sensors, Actuators and Microsystems Laboratory (Prof. Nico F. de Rooij, Institute of Microengineering, EPFL)
BioMEMS Lab (Prof. Marc J. Madou, University of California, Irvine)
BioMEMS Research Center (Prof. Mehmet Toner, BMRC, Harvard Medical School)
Microsystems Technology Group (Prof. Martin Gijs, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland)
Microfluidics and Lab-on-a-Chip (Prof. Dongqing Li, Department of Mechanical and Mechatronics Engineering, University of Waterloo)

Biomaterials, Biosensors, and Tissue Engineering Applications

MIT Langer Lab (Prof. Robert S. Langer, Department of Chemical Engineering, MIT)
Jensen Research Group (Prof. Klavs F. Jensen, Department of Chemical Engineering, MIT)
Matsudaira Lab (Prof. Paul Matsudaira, Whitehead Institute, MIT)
Biomolecular Materials Group (Prof. Angela Belcher, Materials Science and Engineering and Biological Engineering, MIT)

The Ingber laboratory (Prof. Donald E. Ingber, Harvard Medical School & Children's Hospital Boston)
Khademhosseini Lab (Prof. Ali Khademhosseini, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School)
Biohybrid Systems lab (Prof. Shoji Takeuchi, Department of Mechanical and Biofunctional Systems, Institute of Industrial Science (IIS), The University of Tokyo)
Laboratory for Multiscale Regenerative Technologies (Prof. Sangeeta Bhatia, MIT)

The Walt Group (Prof. David R. Walt, Dept. of Chemistry, Tufts University)
Abbott Laboratory (Prof. Nicholas L. Abbott, Dept. of Chemical & Biomolecular Engineering, University of Wisconsin, Madison)
Alivisatos Group (Prof. A.P. Alivisatos, Chemistry, University of California, Berkeley)
The Mirkin Research Group (Prof. Chad A. Mirkin, Chemistry, Northwestern Univ.)
The Lieber Research Group (Prof. Charles M. Lieber, Chemistry & Chemical Biology, Harvard Univ.)