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Fabrication of MEMS Devices with Macroporous Silicon Membrane Embedded with Modulated 3D Structures for Optimal Cell Sorting

  • Natalya Tokranova (a1), Xiaojun Feng (a1), Steve Olson (a1), Tang Tang (a1), Bai Xu (a1) and James Castracane (a1)...

Macroporous silicon is a type of porous silicon that has ordered arrays of channels with high aspect ratio. Macroporous silicon with ordered 3-D structures have a variety of applications such as filters for a particle separation, photonic crystals and optical shortpass filters because of their spatially periodic structures [1–3]. These structures can be prepared by the electrochemical etching (ECE) of silicon wafers in hydrofluoric acid (HF). We report here a way to fabricate macroporous silicon membranes with ordered 3D structures that have controlled periodicity and dimensions appropriate for cell sorting. The silicon 3D structures have pores with variable diameters to modulate the flow behavior and optimize cell sorting efficiency. The silicon membranes were fabricated by wet etching of n-type (100) silicon substrate (40–60 W cm) in potassium hydroxide (KOH) solution with isopropyl alcohol at 80 °C. The 3-D structures were prepared by the electrochemical etching (ECE) of the membranes in diluted HF using the backside illumination with modulated intensity. The thickness of the fabricated membrane has been varied from 20 to 200 mm to optimize filtration of the cells by MEMS (Micro-ElectroMechanical Systems) chips designed for biological cell sorting and cell positioning. The software packages IntelliSuite and ANSYS FLOWTRAN were used to study the mechanical strength of the membrane as well as the velocity profile and flow behavior of Newtonian fluids inside the macroporous silicon membrane.

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1. Schilling, J., Muller, F., Matthias, S., Wehrspohn, R. B., and Gosele, U.Three-dimensional photonic crystals based on macroporous silicon with modulated pore diameterApplied Physics Letters, February 2001, Vol.78, N 9, pp.11801182
2. Lehmann, V., Stengl, R., and Reisinger, H.Optical shortpass filters on macroporous siliconApplied Physics Letters, January 2001, Vol.78, N 5, pp.589591
3. Kettner, C., Reimann, P., Hanggi, P., Muller, F.Drift ratchetPhysical Review E, 2000, Vol.61, N 1, pp.312323
4. Iosub, R., Moldovan, C., Modreanu, M.Silicon membranes fabrication by wet anisotropic etchingSensors and Actuators, 2002, A99, pp.104111
5. Divan, R., Moldovan, N., Camon, H.Roughning and smoothing dynamics during KOH silicon etchingSensors and Actuators, 1999, V.74, pp.1823
6. Lehmann, V. and Foll, H.Formation Mechanism and Property of Electrochemically Etched Thenches in n-Type SiliconJ. Electrochem. Soc., 1990, Vol.137, N 2, pp.653659
7. Lehmann, V.The Physics of Macropore Formation in Low Doped n-Type SiliconJ. Electrochem. Soc., 1993, Vol.140, N 10, pp.28362843
8. Foll, H., Christophersen, M., Carstensen, J., Hasse, G.Formation and application of porous silicon”, Materials Science and Engineering, 2002, R39, pp.93141
9. Lehmann, V.The physics of macroporous silicon formation”, Thin Solid Films, 1995, Vol.255, pp.14
10. Grigoras, K., Niskanen, A. J., Franssila, S.Plasma etched initial pits for electrochemically etched macroporous silicon structuresJ. Micromech. Microeng. 2001, Vol.11, pp.371375
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