NIST Polymers Division Banner NIST Polymers Division Materials Science and Engineering Laboratory National Institutes of Standards and technology
NIST Polymers Division Logo Side bar NIST Polymers Characterization group logo NIST Polymers Electronics group logo NIST Polymers Biomaterials group logo NIST Polymers Multiphase group logo NIST Polymers Processing group logo NIST Polymers Combi group logo Side bar
 Our Publication:
 Group:

 Year:


 
 
button HOME
button Wet Nanomanufacturing
    button Materials Metrology with Microfluidics
  button Porous Protein Mimics
button Nanotube Processing Project
  button Anisotropy in Shear Flow
  button Extraordinary Flow Characteristics of Nanotube-Filled Polymer Materials
  button SANS of Labeled SWNT Dispersions and Clusters
  button Chromatographic Separation and Analysis of Dispersed SWNT
button Quantification of Processing Flows
  button Real-Time Measurements of Extent of Exfoliation
  button Flow-Induced Structure in Micro-Confined Immiscible Polymer Blends
  button Frust-TIR: New Measurement Technique for Coating Kinetics
 

line 		line  
 

Materials Metrology with Microfluidics
line
 

Introduction

line
Objective: Exploit fine flow control of microfluidics for materials metrology.
Advantages:
  • Small sample volumes, individual particles.
  • Rapid measurement.
  • Monitor kinetic processes.
    		•
     

    Experimental Approach
    line
    Microfluidic traps
     
    Carbon nanotube cluster in a cross-slot microfluidic trap. Real-time image analysis feedback traps particle at the stagnation point. Emulsion in a microfluidic trap with adjustable flow type, analogous to a 4-roll mill. mPIV analysis of flow field.
    Carbon nanotube cluster in a cross-slot microfluidic trap.
    		 Real-time image analysis feedback traps particle at the stagnation point.
    		 Emulsion in a microfluidic trap with adjustable flow type, analogous to a 4-roll mill.
    		 mPIV analysis of flow field.
     
    Other microfluidic instruments
    Bioreactor
  • Microfluidic manipulation.
  • Monitor T, pH, glucose, O2, CO2, pressure, and stress.
  • Determine efficient process conditions to produce engineered tissue, cells and biomolecules.
    Interfacial tension
  • Rapid measurement (>100 datapoints/s) interfacial tension in seconds.
  • Accurate within a few percent. e.g., oil/water tension: 31.8 ± 0.8 mN/m
  • Determine surfactant sorption kinetics.
    Efficiently adjust composition.
    		•
     

    Results

    line
    Cluster breaking statistics
  • Dispersion rate v. stress
  • Fragmentation frequency distribution.
    		•  Stretching of wormlike micelles in extensional flow
  • “Molecular individualism.” cf. Chu.
    		•  Unprecedented flow control
  • Complete range of planar flow type §.
    		•  Chaotic mixing
    Oscillatory transverse flow with steady throughput.
  • Exponential material line stretch.
  • Positive Lyupanov exponent.
    • Cluster breaking statistics Stretching of wormlike micelles in extensional flow Unprecedented flow control Chaotic mixing
     

    Publications

    line
    “Microfluidic analogue of the 4-roll mill” S. D. Hudson, F. R. Phelan Jr., M. D. Handler, J. T. Cabral, K. B. Migler, E. J. Amis, Appl. Phys. Lett., 85 (2004).
    “Fluid dynamics of channel flow geometries for materials characterization in microfluidic devices,” F. R. Phelan Jr., S. D. Hudson and M. D. Handler, Rheol.Acta, submitted.
     

    Contributors:

    line
    Hudson, Migler, Phelan, Start, Stone, Pathak, Cabral, Taboas
     
    		 
    		 
    line
    NIST Logo
    Processing Characterization Group
    Polymers Division
    Materials Science and Engineering Laboratory
     
    		NIST Polymers Division Logo