LIDE: high aspect ratio glass processing technology for the mass production of microfluidic devices for biomedical applications

Microfluidic devices are broadly used in research, diagnostics, analytics and many more fields. Their eligibility to run with small amounts of sample are one driving force to expand their utilization into more applications. While glass is an ideal material for microfluidics, few technologies for the micromachining of glass are available. They are usually limited regarding precision and freedom of design, and introduce stress, cracks or other damage into the material. Additionally, they are restricted to certain glass types or do not meet the throughput requirements for mass production. In this work, we discuss - in the context of microfluidics - the recently developed Laser-Induced Deep Etching (LIDE) technology that has overcome the aforementioned issues. It is shown how a broad range of features such as high-aspect ratio through holes, cutouts, slits etc. are realized without introducing stress or other deficiencies. Furthermore, the LIDE technology is discussed in relation to accessory technologies such as glass-plastics and glass-glass joining, as well as selective metallization. These accessory technologies are critical for utilization in areas such as medical diagnostics, single cell studies, lab-on-a-chip applications and many more.