Demand has increased for the double-sided moulding of microfluidic devices for a series of biochemical analyses. Accurate alignment of mould inserts is a critical aspect to transfer doubled-sided patterns on the top and bottom surfaces of a moulded part. A method of mould alignment was studied for double-sided hot embossing of polymer microfluidic devices. An alignment method was designed using kinematic constraints, and a set of three locating pins. To validate the alignment method, two brass mould inserts with fluidic reservoirs were used for the double-sided moulding of prototype microfluidic devices. The kinematic constraints were used to align the mould inserts with each other on the hot embossing machine. The misalignment of double-sided features on the moulded parts was measured using a measuring microscope. The X- and Y-magnitudes of the mismatches ranged from −28 to 118 µm along the X-axis of the moulded parts. The X- and Y-magnitudes of the mismatches along the Y-axis of the moulded parts varied from −38 to 141 µm. The results of the experiments showed that the mould alignment using kinematic constraints is applicable to the fabrication of double-sided patterns for microfluidic devices.

References

1. 1)
  - 13. Sankar, A.R., Jency, J.G., Ashwini, J., Das, S.: ‘Realisation of silicon piezoresistive accelerometer with proof mass-edge-align-flexures using wet anisotropic etching’, Micro Nano Lett., 2012, 7, pp. 118–121 (doi: 10.1049/mnl.2011.0717).
2. 2)
  - 5. Karlsson, J.M., Haraldsson, T., Carlborg, C.F., Wijngaart, W.: ‘A double-sided micromolding process for reproducible manufacturing of thin layers and 3D microchannels in PDMS’. Proc. Micro TAS, Okinawa, Japan, 2012, pp. 659–661.
3. 3)
  - 6. Dittrich, H., Mehne, C., Heckele, M.: ‘Double-sided large area hot embossing for polymer microstructures with high aspect ratio’. Proc. HARMST, Gyenogju, Korea, 2005, pp. 226–227.
4. 4)
  - 2. Luo, Y., Yan, X., Qi, N., Wang, X., Wang, L.: ‘Study of double-side ultrasonic embossing for fabrication of microstructures on thremoplastic polymer’, PLOS ONE, 2013, 8, p. e61647 (doi: 10.1371/journal.pone.0061647).
5. 5)
  - 10. Whitney, D.E.: ‘Mechanical assemblies: their design, manufacture, and role in product development’ (Oxford University Press, New York, 2004).
6. 6)
  - 3. Yang, C.-H., Yang, S.-Y.: ‘A high-brightness light guide plate with high precise double-sided microstructures fabricated using the fixed boundary hot embossing technique’, J. Micromech. Microeng., 2013, 23, p. 035033 (doi: 10.1088/0960-1317/23/3/035033).
7. 7)
  - 4. Han, A., Graff, M., Wang, O., Frazier, B.: ‘An approach to multilayer microfluidic systems with integrated electrical, optical, and mechanical functionality’, Sensors J., 2005, 5, pp. 82–89 (doi: 10.1109/JSEN.2004.838666).
8. 8)
  - 12. Jiang, L., Pandraud, G., French, P.J., Spearing, S.M.: ‘A novel method for nanoprecision alignment in wafer bonding applications’, J. Micromech. Microeng., 2007, 17, pp. S61–S67 (doi: 10.1088/0960-1317/17/7/S01).
9. 9)
  - 7. You, B.H., Chen, P.-C., Park, D.S., et al: ‘Passive micro-assembly of modular, hot embossed, polymer microfluidic devices using exact constraint design’, J. Micromech. Microeng., 2009, 19, pp. 125025 (doi: 10.1088/0960-1317/19/12/125025).
10. 10)
  - 9. Madou, M.J.: ‘Fundamentals of microfabrication: the science of miniaturization’ (CRC Press, New York, 2002).
11. 11)
  - 1. Skafte-Pedersen, P., Sip, C.G., Folch, A., Dufva, M.: ‘Modular microfluidic systems using reversibly attached PDMS fluid control modules’, J. Micromech. Microeng., 2013, 23, p. 055011 (doi: 10.1088/0960-1317/23/5/055011).
12. 12)
  - 14. Anton, H., Rorres, C.: ‘Elementary linear algebra: applications version’ (Willey, Hoboken, NJ, 2000).
13. 13)
  - 8. Bäcklund, Y.J.: ‘Micromechanics in optical microsystems – with focus on telecom system’, J. Micromech. Microeng., 1997, 7, pp. 93–98 (doi: 10.1088/0960-1317/7/3/003).
14. 14)
  - 11. Slocum, A.H., Weber, A.C.: ‘Precision passive mechanical alignment of wafers’, JMEMS, 2003, 12, pp. 826–834.

Method of mould alignment for double-sided hot embossing of microfluidic devices using kinematic constraints

References

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