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Estimation of mixing fields in micromixers and microreactors by visualization method using methylene blue solution

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Abstract

During the development of micromixers and microreactors, it is important to assess the concentration field and mixing status in their microchannels. Therefore, this study establishes a visualization method for evaluating the concentration field using images of dilution of a methylene blue solution with water. Noted that the original methylene blue solution is deep blue before it is mixed with water; it becomes paler once it is diluted, as observed against a white background. Because the methylene blue concentration has a highly reliable relationship with the saturation of the captured color, the local methylene blue concentration can be determined on the basis of a calibration result obtained in advance. The saturation value is affected not only by the concentration but also by the optical effect of the channel walls. Therefore, we established a method of eliminating the channel wall effect. As a trial, we estimated the concentration field in our novel microreactor using the proposed visualization method and estimated the mixing status in the microchannel. We showed that the proposed visualization method effectively estimated the concentration field and mixing status in micromixers and microreactors.

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Abbreviations

B :

Blue intensity

C :

Methylene blue concentration

C 0 :

Original methylene blue concentration before mixing

C + :

Normalized concentration (≡C/C 0)

G :

Green intensity

I :

Light intensity

R :

Red intensity

S :

Saturation

S′:

Compensated saturation (\(\equiv S/\overline{S^+}\))

S 0 :

Most frequently occurring saturation value in an image

S + :

Normalized saturation (≡S/S 0)

\(\overline{S^+}\) :

Ensemble mean value of S +

References

  • Chung CK, Shih TR, Chang CK, Lai CW, Wu BH (2011) Design and experiments of a short-mixing-length baffled microreactor and its application to microfluidic synthesis of nanoparticles. Chem Eng J 168:790–798

    Article  Google Scholar 

  • Dinh TX, Ogami Y (2008) Effect of optical rotor on mixing in Y-shaped microchannel flow. J Fluid Sci Technol 3:250–259

    Article  Google Scholar 

  • Ehrfeld W, Hessel V, Loewe H (2000) Micro-reactors—new technol. for modern chemistry. Wiley/VCH, New York/Weinheim

    Google Scholar 

  • Fu X, Liu S, Ruan X, Yang H (2006) Research on staggered oriented ridges static micromixers. Sensors Actuators B 114:618–624

    Article  Google Scholar 

  • Fujiwara T, Ohue H, Ushijima T, Kitoh O (2007) Optimization of channel geometry and pumping conditions for an alternate pumping microreactor. J Fluid Sci Technol 2:389–399

    Article  Google Scholar 

  • Glasgow I, Aubry N (2003) Enhancement of microfluidic mixing using time pulsing. Lab Chip 3:114–120

    Article  Google Scholar 

  • Kaneko T, Izawa S, Xiong AK, Fukunishi Y (2004) Mixing enhancement of two liquids by active control in a millimeter-scale channel flow. In: Proceedings of 10th Asian Congr. Fluid Mech., A19

  • Kudo S, Maki T, Kono H, Olea M, Mae K (2010) Enhancing reaction selectivity by intentional control of concentration profile in catalytic microreactor. J Chem Eng Jpn 43:63–69

    Article  Google Scholar 

  • Ko YJ, Ha SM, Kim HJ, Lee DH, Ahn Y (2008) Development of a PDMS-Glass hybrid microchannel mixer composed of micropillars and micronozzles. J Solid Mech Mater Eng 2:445–454

    Article  Google Scholar 

  • Lee Y, Shih C, Tabeling P, Ho C (2007) Experimental study and nonlinear dynamic analysis of time-periodic microchaotic mixers. J Fluid Mech 575:425–448

    Article  MathSciNet  MATH  Google Scholar 

  • Masuda Y, Aizawa T, Suzuki A (2009) Flow visualization and numerical simulation of T-junction mixing of high-temperature high-pressure water. J Chem Eng Jpn 42:64–70

    Article  Google Scholar 

  • Mitsuhashi Y, Yamzaki K, Kobayashi E, Yoneya A, Ono N (2011) Fluid-flow analysis for a novel cylindrical micromixer. J Fluid Sci Technol 6:230–241

    Article  Google Scholar 

  • Sheen HJ, Hsu CJ, Wu TH, Chu HC, Chang CC, Lei U (2007) Experimental study of flow characteristics and mixing performance in a PZT self-pumping micromixer. Sensors Actuators A 139:237–244

    Article  Google Scholar 

  • Tan CKL, Tracey MC, Davis JB, Johnston ID (2005) Continuously variable mixing-ratio micromixer with elastomer valves. J Micromech Microeng 15:1885–1893

    Article  Google Scholar 

  • Tsai J, Lin L (2002) Active microfluidic mixer and gas bubble filter driven by thermal bubble micropump. Sensors Actuators A 97–98:665–671

    Article  Google Scholar 

  • Yamada T, Osato N, Watanabe Y, Ono N (2011) Experimental and numerical study on micromixing by utilizing the movement of gas–liquid free interface. J Fluid Sci Technol 6:128–138

    Article  Google Scholar 

  • Yamaguchi Y, Ogino K, Yamashita K, Maeda H (2004) Rapid micromixing based on multilayer laminar flows. J Chem Eng Jpn 37:1265–1270

    Article  Google Scholar 

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Correspondence to Tamio Fujiwara.

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Fujiwara, T., Urata, T. & Ohue, H. Estimation of mixing fields in micromixers and microreactors by visualization method using methylene blue solution. J Vis 15, 197–205 (2012). https://doi.org/10.1007/s12650-012-0126-1

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  • DOI: https://doi.org/10.1007/s12650-012-0126-1

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