Improving the Mixing Uniformity of Microfluidic Mixers

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Improving the Mixing Uniformity of Microfluidic
Mixers

• This project continues to focus on the
  development of microfluidic mixers for use with a
  variety of experimental probes of macromolecular
  folding, including x-ray scattering and
  fluorescence microscopy. Much of our experimental
  work is carried out using x-ray beams with
  dimensions of order 10s of microns, thus the
  width of the microfluidic channel must be of
  order 50 microns to allow passage of the x-rays
  through the through-etched channel without
  touching the walls.
• We have constructed, tested and simulated the
  flow conditions within a re-designed mixer. The
  use of two additional channels allows us to
  decouple the hydrodynamic focusing process from
  the diffusive mixing that triggers the
  conformational changes of interest. The sharpness
  of the mixing increases by an order of magnitude
  relative to earlier versions of this device. This
  improvement enables sub-millisecond mixing
  reactions of ionic species with macromolecules,
  such as those triggering the folding of RNA and
  has allowed us to study this process in detail.

Lois Pollack, Cornell University Work performed
at Cornell Nanoscale Facility