GeSiM offers different approaches for micromachining of 3D structures. Microfluidic devices are easily made from silicon/glass sandwiches. However, many applications require optical transparent channel structures. Glass/glass sandwiches are precise but more expensive and give high accuracy (see next menu point).
PDMS microfluidics keeps prices close to disposables but requires more initial instrumentation. Please refer to the GeSiM MicCell or even the Micro-Contact-Printers. The latter one prints your microfluidic devices (NIL – Nano-Imprint-Lithography) but manage sample handling too by onboard pipettors.
Right: Different sandwich methods for microfluidic devices.
3D Microfluidics from Hard Materials
- Anisotropic wet-chemical etching of Si with KOH: inexpensive batch process, smooth surface, side wall angle depends on crystal orientation
- Anisotropic plasma-enhanced dry Si etching (ASE/Bosch process): single wafers, dense structures, vertical side walls
- Super-rough surfaces by etching in SF6/C4F8 plasma
- Isotropic wet etching of glass with HF: round channels, 3 – 700 µm deep
- Ultrasonic drilling and micro-blasting for 150 – 1000 µm thick glass, Si, quartz