Manufacture of microfluidic glass chips by deep plasma etching, femtosecond laser ablation, and anodic bonding

Abstract

International audienceTwo dry subtractive techniques for the fabrication of microchannels in borosilicate glass were investigated, plasma etching and laser ablation. Inductively coupled plasma reactive ion etching was carried out in a fluorine plasma (C4F8/O2) using an electroplated Ni mask. Depth up to 100 μm with a profile angle of 83°-88° and a smooth bottom of the etched structure (Ra below 3 nm) were achieved at an etch rate of 0.9 μm/min. An ultrashort pulse Ti:sapphire laser operating at the wavelength of 800 nm and 5 kHz repetition rate was used for micromachining. Channels of 100 μm width and 140 μm height with a profile angle of 80-85° were obtained in 3 min using an average power of 160 mW and a pulse duration of 120 fs. A novel process for glass-glass anodic bonding using a conductive interlayer of Si/Al/Si has been developed to seal microfluidic components with good optical transparency using a relatively low temperature (350°C)

Low temperature direct bonding of silica glass via wet chemical surface activation

“…[9][10][11][12][13][14] Smooth interfaces have been obtained with this method, even at room temperature. However, it requires more rigorous conditions than the traditional fusion bonding method.…”

Packaged integrated opto-fluidic solution for harmful fluid analysis

“…The quality of the process therefore lies on the cleanness of the wafer surfaces and the environment as well as surface activation procedure used to increase the number of OH groups. The bonding itself is essentially based on three mechanisms: spontaneous adhesion, slow fracture effect and consolidation by annealing [14][15][16][17] .…”

Fabrication of microfluidic structures in quartz via micro machining technologies

“…Microfluidic channel control technology for producing microspheres have advantages such as good size controllability (Hisamoto et al 2001), high reaction efficiency (Dittrich and Manz 2006), short process time (Brivio et al 2006), structures requires stacking and bonding, leading to increased complexity and cost (Liu et al 2012). Femtosecond laser technology has thus been used by many research groups for fabricating 3D microfluidic structures (Zheng and Lee 2005;Bhuyan et al 2010;Queste et al 2010;Liu et al 2012). Zheng and Lee (2005) used a CO 2 laser along the movement path of the beam to machining glass material removal.…”

“…The experimental results showed that the obtained microfluidic channels had a 2-µm diameter and aspect ratios of up to 40. Queste et al (2010) manufactured microfluidic glass chips by using deep plasma etching, femtosecond laser ablation, and anodic bonding. The results showed that the obtained laser-and etching-cut microfluidic channels were 100 μm wide and 140 μm high, with a profile angle of 80°-85°.…”