Femtosecond laser 3D micromachining: a powerful tool for the fabrication of microfluidic, optofluidic, and electrofluidic devices based on glass

Abstract

Femtosecond lasers have unique characteristics of ultrashort pulse width and extremely high peak intensity; however, one of the most important features of femtosecond laser processing is that strong absorption can be induced only at the focus position inside transparent materials due to nonlinear multiphoton absorption. This exclusive feature makes it possible to directly fabricate three-dimensional (3D) microfluidic devices in glass microchips by two methods: 3D internal modification using direct femtosecond laser writing followed by chemical wet etching (femtosecond laser-assisted etching, FLAE) and direct ablation of glass in water (water-assisted femtosecond laser drilling, WAFLD). Direct femtosecond laser writing also enables the integration of micromechanical, microelectronic, and microoptical components into the 3D microfluidic devices without stacking or bonding substrates. This paper gives a comprehensive review on the state-of-the-art femtosecond laser 3D micromachining for the fabrication of microfluidic, optofluidic, and electrofluidic devices. A new strategy (hybrid femtosecond laser processing) is also presented, in which FLAE is combined with femtosecond laser two-photon polymerization to realize a new type of biochip termed the ship-in-a-bottle biochip.

Capillary microfluidics in microchannels: from microfluidic networks to capillaric circuits

“…Trenches formed at the bottom of the laser-etched microchannels and liquid was observed to be trapped in some of these dead end trenches during rinsing. These results nonetheless showcase the potential of laser writing for rapid prototyping of CCs and improvements might be possible by using higher resolution Nd:YAG lasers 125 or nanosecond and femtosecond lasers, 126 although more advanced lasers have not been used for making CCs to the best of our knowledge.…”

A Compound Parabolic Concentrator Coupled to an Optical Microlenslet Array for Projection Display

“…According to the design of CPC earlier, the dielectric rectangular CPC is fabricated with PMMA by injection molding, extrusion and casting processing. Then, it bonds well with the microlenslet array previously prepared by the thermal pressed treatment [9]. Finally, the light collection engine comes into shape with the structure of the dielectric rectangular CPC coupled to an optical microlenslet array, as shown in Fig.…”

Nanodrilling of fused silica using nanosecond laser radiation

“…The direct ablation process with short [1,2] and ultrashort laser pulses [3][4][5][6] allows the well-defined drilling of different materials like dielectrics, polymers, semiconductors, and metals. Especially the usage of fs laser radiation allows the fabrication of holes in dielectric surfaces with diameters in the sub-m range with a high aspect ratio [7][8][9] using Bessel beams.…”