Table 1.

Contact angles of solvents on various microchannel materials and the component (${\gamma }_{\mathrm{S}}^{\mathrm{d}}$ and ${\gamma }_{\mathrm{S}}^{\mathrm{p}}$) and total ( γ _S ) solid surface free energies

Solid surface material	Solvent	Average contact angle (o)	${\mathit{\gamma }}_{\mathbf{S}}^{\mathbf{d}}$ (mJ/m2)	${\mathit{\gamma }}_{\mathbf{S}}^{\mathbf{p}}$ (mJ/m2)	γ S (mJ/m2)
PTFE	Water	106 ± 2	28 ± 1	0.1 ± 0.1	28 ± 1
	Toluene	23 ± 2
FEP	Water	103 ± 1	21 ± 1	0.8 ± 0.2	22 ± 1
	Toluene	40 ± 1
3D‐printed plastic	Water	121 ± 5	36 ± 13	2 ± 14	38 ± 30
	Toluene	0

Abbreviations: PTFE, polytetrafluoroethylene; FEP, fluorinated ethylene propylene.