This paper reported a three-dimensional microfluidic channel structure, which was fabricated by Yb:YAG 1026?nm femtosecond laser irradiation on a single-crystalline diamond substrate. The femtosecond laser irradiation energy level was optimized at 100?kHz repetition rate with a sub-500 femtosecond pulse duration. The morphology and topography of the microfluidic channel were characterized by a scanning electron microscope and an atomic force microscope. Raman spectroscopy indicated that the irradiated area was covered by graphitic materials. By comparing the cross-sectional profiles before/after removing the graphitic materials, it could be deduced that the microfluidic channel has an average depth of ~410?nm with periodical ripples perpendicular to the irradiation direction. This work proves the feasibility of using ultra-fast laser inscription technology to fabricate microfluidic channels on biocompatible diamond substrates, which offers a great potential for biomedical sensing applications.
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The following article appeared in Su, S., Li, J., Lee, G., Sugden, K., Webb, D., & Ye, H. (2013). Femtosecond laser-induced microstructures on diamond for microfluidic sensing devices applications. Applied physics letters, 102(23),  and may be found at http://link.aip.org/link/?apl/102/231913
The authors want to acknowledge the funding for this study provided by the Engineering and Physical Sciences Research Council (EPSRC: EP/H034269/1).
- atomic force microscopy
- surface topography
- surface morphology
- scanning electron microscopy
- Raman spectra
- laser beam effects
- high-speed optical techniques
- crystal microstructure