Table 1.

Properties of materials and processing technologies typically used for the fabrication of microfluidic devices (adapted from [11]).

Material/Property	Silicon/Glass	Elastomers	Thermosets	Thermoplastics	Hydrogel	Paper
optical transparency	no/high	high	high	medium to high	low to medium	low
hydrophobicity	hydrophilic	hydrophobic	hydrophobic	hydrophobic	hydrophilic	amphiphilic
thermostability	very high	medium	high	medium to high	low	medium
resistance to oxidizer	excellent	moderate	good	moderate to good	low	low
solvent compatibility	very high	low	high	medium to high	low	medium
permeability to oxygen (Barrer a)	<0.01	≈500	0.03–1	0.05–5	>1	>1
surface charge	very stable	not stable	stable	stable	N/A	N/A
common technique for microfabrication/features	photolithography, laser-assisted etching	casting	casting, photopolymerization	thermo-molding	casting, photopolymerization, 3D bioprinting	photolithography, printing
smallest channel dimension	<100 nm	<1 μm	<100 nm	≈100 nm	≈10 μm	≈200 μm
channel profile	limited 3D/3D	3D	arbitrary 3D	3D	3D	2D
multilayer channels	hard/easy	easy	easy	easy	Medium	easy
throughput	medium to high	high	high	high	low to medium	high

^a Barrer = 10⁻¹⁰ [cm³ O₂(STD)] [12] cm cm⁻² s⁻¹ cmHg⁻¹.