Microfluidics: Complex structures in hard-brittle materials

Microfluidics deals with the control of small fluid volumes and is classified as a key technology in analytics. Possible applications of microfluidic components can be found, for example, within biotechnology, drug discovery or (point-of-care) diagnostics.

Exemplary applications:

Lab-on-a-chip
Organ-on-a-chip
Microanalysis systems
Microreactors

In particularly demanding microfluidic applications, the advantages of hard-brittle materials such as glass outweigh their disadvantages:

	Glass	Polymer	Ceramic
Optical properties	+++	+	--
Chemical resistance	++	o	+++
Surface characteristics	++	o	--
Thermal stability	++	+	+++
Hydrophilicity	+++	-	/
Shelf life	+	-	+++
Reproducibility	++	o	/
Coating capability	+	o	--
NRE costs	+	--	--
Price per piece (series)	-	+++	--

Source: MF Consortium of CfBI "Desing for Microfluidic Device Manufacture Guidelines", V5.

Exemplary Materials:

Fused silica
Borosilicate glass
Calcium fluoride
Zerodur
Zirconia
Silicon carbide

Manufacturable geometries:

Micro holes
Wells
Reservoirs
Complex 3D channels
Branches
Threads
Inlet/outlet ports
and others...

Due to our high-precision 5-axis CNC machining process, three-dimensional microfluidic structures made of glass can be produced economically even for small batch sizes and complex geometries. An application-specific selection of different hard-brittle materials (e.g. calcium fluoride for applications in Raman spectroscopy) can be made.

Our technology offers the following advantages in comparison to available manufacturing alternatives:

	Etching processes	Laser processes	Selective laser etching (SLE)	ShapeFab (combined CNC machining)
Fast prototyping / small and medium batch sizes	𐄂	✔	✔	✔
High volumes	✔	𐄂	𐄂	𐄂
No use of environmentally harmful chemicals	𐄂	✔	✔	✔
Low heat input into the component	✔	𐄂	𐄂	✔
High aspect ratio	𐄂	✔	✔	✔
Selective polishing	𐄂	𐄂	𐄂	✔
Vertical channel walls	𐄂	𐄂	✔	✔
Transition of different channel depths	𐄂	𐄂	✔	✔