Masashi lkeuchi and koji lkuta THE MEMBRANE MICRO EMBOSS (MeME) PROCESS FOR FABRICATING 3-D MICROFLUIDIC DEVICE FORMED FROM THIN POLYMER MEMBRANE Masashi lkeuchi and koji lkuta Dept. of Micro/Nano Systems Eng., School of Eng., Nagoya University, Japan MicroTAS 2006, pp. 693-695 Student：陳睿鈞

Outline Introduction Fabrication Result Application Conclusion

- Introduction - Fabrication - Result - Application - Conclusion

Introduction “Membrane micro emboss (MeME) process” realizes arbitrary 3-D microstructures made of thin polymer membrane. The reduced thickness of the wall enables significantly enhanced heat and mass exchange between the inside and the outside of the microchannel. Conventional microfluidic device Membrane microfluidic device

Membrane Microfluidic Devices For Filtration An array of microfabricated structures A large membrane filter Y. Tezuka (2002) S. Thorslund(2006) 3D membrane microchannel structure The whole surface of the microchannel itself works as a large filter Masashi Ikeuchi (2006)

- Introduction - Fabrication - Result - Application - Conclusion

MeME Process 1 4 2 5 3 Master mold Heat-seal with another membrane Thermo-plastic membrane Deformable plastic support substrate 2 5 Remove the support substrate Press around the glass transition temperture of the membrane PLA Tg=55°C Membrane microfluidic device 3 Cool down to room temperature and then remove the mold

The Effect of Process Condition - Pressing Time and Speed Poly-lacticacid (thickness=5μm) was used as membrane material and paraffin was used as a support substrates. Pressing Time period Pressing speed time > 250sec Height is not affected Pressing speed affect the height of the microchannel

The Effect of Process Condition - Property of Support Substrates Melting point of paraffin = 60°C, 70°C Height of the microchannel : 70°C > 60°C

The Effect of Process Condition - Pressure transition Pressure transition during the MeME process under several process conditions Influence : pressing speed > mp. of paraffin

- Introduction - Fabrication - Result - Application - Conclusion

Process Resolutions lateral resolution vertical resolution Lateral resolution 15μm vertical resolution 1μm

Prototype Fabrication Demonstrate the fabrication of highly branched microchannels formed from poly-lacticacid membrane with thickness of 5μm. The honeycomb-like master mold Underside of the membrane microchannel Red solution Upperside of the membrane microchannel

- Introduction - Fabrication - Result - Application - Conclusion

Mesoporous Polymer Membrane Poly-lacticacid solution dissolved in dioxane-water mixed solvent was spin-coated on a glass substrate and dried in vacuo. The pore diameter and the porosity were tunable by adjusting the polymer content in the solution and the water content in the dioxane. PLA concentration 100mg/ml Water/dioxane 7% Higher PLA concentration decreased the pore density

Size-Selective Separation The paper demonstrated the on-site size-selective sampling using suspension of microbeads ranging from 0.1μm to 15μm in diameter. Filled with red colored water Microchannel Width 50μm Height 50μm Membrane thickness 5μm Large bead (ψ＞1μm) : trapped Small bead (ψ＜1μm) : penetrating

Conclusion MeME process fabricate membrane microfluidic devices with high precision, speed and simplicity. The process is applicable to various material, since it requires only thermo-plasticity of the membrane material. The membrane microfluidic device will open the way to new application of biological and chemical analysis. blood Diameter(μm) erythrocyte 6～8 leukocyte 8 ～12 platelet 2～4 Wikipedia

References Masashi Ikeuchi and Koji Ikuta “On-Site Size-Selective Particle Sampling Using Mesoporous Polymer Membrane Microfluidic Device”, The 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences (μTAS 2006) Tokyo, Japan, November 5-9, 2006, pp.1169-1171, (2006). S. Thorslund et. al., “A hybrid poly(dimethylsiloxane) microsystem for on-chip whole blood filtration optimized for steroid screening”, Biomed Microdevices, vol.8, pp.73-79, (2006). Y. Tezuka et. al., “DNA size separation employing micro-fabricated monolithic nano-structure”, Proc. Micro Total Analysis Systems 2002, pp.212-214, (2002).

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