Nanoscale surface modifications to control capillary flow characteristics in PMMA microfluidic devices

Table 2 Values of diffusion coefficients and surface tension parameters from analytical simulation on each position-time curve of all the microfluidic flow

Surface modification	Surface structure	Diffusion coefficient, D(ρm² s^-1)	γ_sa - γ_sl N/m
Air DBD processed	Flat surface	66153420	0.004330
	100 μm pillar	38677500	0.002531
	200 μm pillar	23777420	0.001556
	300 μm pillar	12537020	0.000820
Nitrogen plasma treated	Flat surface	45091690	0.002951
	100 μm pillar	20411460	0.001336
	200 μm pillar	12500060	0.000818
	300 μm pillar	11718310	0.000767
Control PMMA	Flat surface	6337320	0.000414
	100 μm pillar	3219800	0.000210
	200 μm pillar	2142380	0.000140
	300 μm pillar	1477070	0.000096
Undoped DLC coated	Flat surface	10878150	0.000712
	100 μm pillar	3993380	0.000261
	200 μm pillar	2983690	0.000195
	300 μm pillar	1782760	0.000116
Si-doped DLC coated	Flat surface	4044020	0.002646
	100 μm pillar	2058300	0.000134
	200 μm pillar	1449660	0.000094
	300 μm pillar	1175890	0.000076