Table 2.

Microfluidic synthesis of nanoparticles by passive mixing methods

Nanoparticle type	Mixing mechanism/microchannel	Size (nm)	PDI	Organic/precursor concentration	FRR	TFR	ME	MT	Year	References
Liposomes	Concentric laminar flow/PDMS mixer	120	–	1 mM	4	20.4 µL/min	–	–	2012	[150]
Liposomes	Semicircular contraction–expansion array (Dean flow)/PDMS/glass microchannel	50	–	10 mM	9	18 mL/h	90%	–	2013	[151]
Liposomes	Periodic disturbance mixer (Dean flow)/PDMS/glass microchannel	30	0.22	5 mM	3	18 mL/h	> 90%	< 120 ms	2021	[152]
Liposomes	Serpentine microchannel with baffles (contraction–expansion regions)/PDMS/glass microchannel	118	0.2	25 mM	5	11.8 mL/min	–	–	2013	[153]
Liposomes	Staggered herringbone mixer/PDMS/glass microchannel	30	0.1	5 mg/mL	10	500 µL/min	80%	< 300 ms	2017	[105]
Lipid nanoparticle	2D-baffle PDMS mixer device (invasive lipid NP production device/PDMS/glass microchannel	20	0.1	10 mg/mL	20	500 µL/min	90%	6 ms	2018	[154]
Liposomes	Double flow focusing/PDMS/glass microchannel	150	0.23	5 mM	10	65 mL/h	–	–	2021	[141]
Lipid nanoparticle	Segmented-Axis symmetric glass microchannel	70	0.15	5 mg/mL	10	130 μL/min	–	–	2019	[157]
Liposomes	Periodic disturbance mixer (Dean flow)/PDMS/glass microchannel	90	0.18	10 mM	8.56	18 mL/h	–	–	2020	[164]
Liposomes	Serpentine/PMMA polymer microchannel	188	0.2	1.5 mg/mL	5	5 mL/min	–	–	2020	[156]
Liposomes	Half-moon design/PLA polymer microchannel	193	0.22	1 mg/mL	1	3 mL/min	–	–	2021	[165]
PLGA	3D origami ship spiral/arc design/PDMS-PDMS microchannel	< 100	0.06	2% wt	17	2.5 mL/h	–	16 ms	2013	[166]
PLGA	Slit interdigital micromixer	211	–	10 mg/mL	1	62.8 mL/min	–	10 ms	2016	[167]
PLGA	Spiral mixer (Dean flow)/PDMS/glass microchannel	69.3	0.2	5 mg/mL	5	132 mL/min	–	< 90 ms	2020	[169]
PLGA	Staggered herringbone mixer (NanoAssemblr™)/COC microchannel	120	0.12	10 mg/mL	3	6 mL/min	–	–	2018	[170]
PLCL	Serpentine design/Asia 320 microfluidic system	30	< 0.12	0.25 mg/mL	5	2 mL/min	–	–	2018	[191]
PCL	Concentric glass capillaries microchannel	200	–	1 mg/mL	10	8.3 mL/h	–	–	2015	[140]
PCL-b-PEO	Segmented flow-based mixer (Taylor flow)/PDMS/glass microchannel	32	–	0.66% wt	1	100 µL/min	–	< 1 s	2016	[168]
AuNPs	Spiral segmented flow-based mixer (Taylor flow)/silicon/glass microchannel	3.8 ± 0.3	–	1 mM	10	300 µL/min	–	–	2012	[171]
AuNPs	Serpentine design/PDMS/glass micorchannel	4.38 ± 0.53	–	10 mM	9:14	2.3 mL/h	–	–	2010	[172]
AuNPs	Integrated micromixer-microreactor-microfluidic platform/PDMS/PDMS microchannel	27 ± 3.5	–	0.02% wt	1	10 µL/min	83%	–	2015	[192]
AuNPs	Serpentine design/PMMA micorchannel	4.5	–	10 M	5:3	0.2 mL/min	–	–	2019	[177]
AgNPs	Double layer Y-shaped split and recombination micromixer/PMMA microchannel	30.5 ± 4.82	–	1 mM	1.5	810 μL/min	–	–	2020	[174]
AgNPs	T-mixer	4.7 ± 0.6	–	0.5 mM	1	1.9 mL/min	–	–	2015	[178]
AgNPs	Corning Advanced-Flow Reactor (AFR) curved split and recombination/glass microchannel	4.6 ± 1.8	–	1.58 mM	2	9 mL/min	60%	–	2021	[175]
Silica	Gear-shaped serpentine micromixer/PDMS/glass microchannel	370.3	–	0.1 M	–	1 mL/h	90%	–	2020	[176]
Lipid-PLGA	Tesla structure micromixer/PDMS/glass microchannel	40	–	1 mg/mL (PLGA)	10	60 μL/min	–	10 ms	2010	[181]
Lipid-QD	Tesla structure micromixer/PDMS/glass microchannel	60	–	0.5 mg/mL (QD)	–	55 μL/min	–	10 ms	2010	[181]
Lipid-PLGA	Spiral micromixer/PDMS/glass microchannel	62.5 ± 1.18	0.173	2.94 mg/mL (lipid), 10 mg/mL (PLGA)	80	246 mL/h	–	–	2015	[182]
Lipid-PLGA	Herringbone patterned multi-inlet vortex mixer	60	0.12	1 mg/mL (PLGA)	–	12 mL/min	> 99%	–	2019	[183]
Au-PLGA	Two consecutive slit-interdigital micromixers	192 ± 58	–	1.25 mg/mL of (PLGA), 0.24 mg/mL (gold)	–	54 mL/h	–	–	2017	[184]
Au-Lipid	Asia MF 320 system flow focusing laminar mixing	130	0.2	4.5 mg/mL(lipid), 2.5 mg/mL (gold)	10	220 μL/min	–	–	2019	[187]

PDI polydispersity index, FRR flow rate ratio, TFR total flow rate, ME mixing efficiency, MT mixing time