The comparison of two main materials in microfluidics, namely glass and polymers, shows their specific strengths and weaknesses. You might want to use glass if your set-up requires elevated temperatures, much above 100°C, which is usually not the case in life sciences, and/or if you need to use specific organic solvents. If you want to store bio-reagents on-chip, you need complex fluidics or hybrid components like membranes, or valves should be part of your device, etc., you will want to choose polymers, since interfaces, reservoirs, and different structural depths do not impact the price of the device in polymers, but are partially impossible to be implemented in a glass device or massively increase the cost. Possessing different characteristics and financial benefits, you will always use polymers when you don’t require glass, since they are the overall cheaper devices.
- Transparency
- Autofluorescence
- Application in UV region
- Surface roughness
- Thermal stability
- Stability against organic solvents
- Stability against standard solvents in life sciences
- Stability against acidic solutions
- Stability against basic solutions
- Unspecific binding of biological components
- Good
- Low (right polymer choice important)
- In near UV special polymers available
- Can be optically smooth
- Depending on polymer choice, 100°C are possible
- Limited
- Polymers available
- High
- High
- Polymers with low unspecific binding available, surface functionalization to avoid the issue available
- Good
- Low
- Quartz glass needs to be chosen
- Depending on technology
- Around 600°C transition to liquid phase
- High
- High
- High
- Medium
- High, surface functionalization to avoid the issue available
- Design freedom
- Combination of different structural depth in one device
- Direct integration of fluidic interface
- Direct integration of e.g. reservoirs
- High
- Easy
- Easy – into injection molded part
- Easy – into injected molded part
- Low
- Difficult, leads to price increase
- Difficult, assembling process needed
- Limited, large structures increase costs
- Integration of liquid and dry reagents
- Integration of hybrid components like filters
- Integration of valves
- Easy
- Easy
- Easy
- Limited to impossible
- Limited to impossible
- Limited to passive and elastomeric membrane valves
- Material cost
- Highest price impact
- Low to medium, 2 – 20€/kg
- Assembly
- High
- Footprint of device, material, microstructuring, assembly