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

Student：陳睿鈞

MicroTAS 2006, pp. 693-695

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.

Membrane microfluidic deviceConventional microfluidic device

Membrane Microfluidic Devices For Filtration

An array of microfabricated structures A large membrane filter

3D membrane microchannel structure

Y. Tezuka (2002)S. Thorslund(2006)

Masashi Ikeuchi (2006)

The whole surface of the microchannel itself works as a large filter

- Introduction

- Fabrication

- Result

- Application

- Conclusion

MeME Process

Master mold

Thermo-plastic membrane

Deformable plasticsupport substrate

Press around the glass transition temperture of the membrane

Cool down to room temperature and then remove the mold

Heat-seal with another membrane

Remove the support substrate

Membrane microfluidic device

1

2

3

4

5

PLA Tg=55°C

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 > 250secHeight 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

Upperside of the membrane microchannel

Red solution

- Introduction

- Fabrication

- Result

- Application

- Conclusion

Mesoporous Polymer Membrane Poly-lacticacid solution dissolved in dioxane-water mixed solv

ent 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/mlWater/dioxane 7%

Higher PLA concentration decreased the pore density

Size-Selective Separation The paper demonstrated the on-site size-selective sampling usi

ng suspension of microbeads ranging from 0.1μm to 15μm in diameter.

Filled with red colored waterMicrochannel 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.

Wikipedia

bloodDiameter(μm)

erythrocyte 6～ 8

leukocyte 8 ～ 12

platelet 2～ 4

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).

The End