Do it yourself- circular cross-section microfluidic channel

Figures & data

Table 1. Comparison of various channel fabrication techniques.

Parameter	Ref. (Gautam et al., 2018)	Ref. (Razavi Bazaz et al., 2020)	Ref. (Tiwari et al., 2020)	Ref. (Kim et al., 2018)
Substrate	Aluminum	–	Glass	Glass
Materials	Aluminum, PDMS	DLP/SLA, PMMA,	PDMS, Glass	PDMS, Glass
Special Equipment	Oxygen plasma cleaner	High resolution 3D Printer	Oxygen plasma cleaner	Oxygen plasma cleaner, Femtosecond laser
Min. feature size (μm)	250	50	350	300
Roughness (nm)	–	300	6	360
Cross section	Rectangular	Rectangular	Rectangular	Semi-circular
Fabrication time(hr.)	>3	<2	∼2*	∼1
Cost	Moderate	Moderate	Moderate	High

* PCB master fabrication time is not included.

Table 2. Comparison of circular microchannel fabrication methods.

	Wire-removal (Effati & Pourabbas, 2018; Li & Xu, 2015; Rathod et al., 2017; Song et al., 2010)	Micro-milling (Choi et al., 2013)	Positive-photoresist Reflow (Abdelgawad et al., 2011)	PDMS Coating (Li & Xu, 2015)	Present Study
Substrate	NA	NA	Si/Glass	Si/Glass	NA
Cleanroom requirement	No	No	Yes	Yes	No
No. of Masks	0	0	1	1	0
Channel diameter (µm)	9–800	1041	100–400	31	240
Reverse molding	No	Yes	No	No	No
Mold surface modification	Yes	Yes	Yes	Yes	No
Mold lifetime (No. of use)	Single	Multiple	Multiple	Multiple	Single
Channel tubing	Metallic tube	Plastic tube	–	–	Scalp vain set tube
Cost	Low	Medium	High	High	Low

Figure 1. Copper wire based mold for straight channel.

Figure 2. Copper wire mold image (a) SEM image (Zoom 200X) (b) SEM image (Zoom 1000X) (c) AFM image (maximum surface roughness 134.4 nm).

Figure 3. SEM image of rubber tube cross-section.

Figure 4. Plastic container for optimal use of PDMS: (a) Top view, and (b) Box in the open state (Tiwari et al., Filed on 18th December 2023).

Figure 5. Plastic container with a layer of aluminum foil (Tiwari et al., Filed on 18th December 2023).

Figure 6. (a) The channel mold attached to the plastic box cover (b) Box filled with PDMS.

Figure 7. PDMS bulk with microchannel and tubing.

Figure 8. (a) Mesh model (b) Straight channel model and (c) Channel model with bending.

Figure 9. Velocity profile in the channel at various distance starting at 0 from inlet (a) Straight channel, and (b) Channel model with bending.

Figure 10. Velocity surface plot at 1 mm distance from the straight channel inlet.

Figure 11. Pressure drop across the channel (a) Straight, and (b) With bends.

Figure 12. Poincaré map at the outlet of the straight channel (a) Time 11.70s (b) Time 11.75s, and (c) Time 20.00s.

Figure 13. Poincaré map at the outlet of the channel with bending (a) Time 11.65s (b) Time 11.70s, and (c) Time 20.00s.

Figure 14. Residence time testing of channel (a) Empty channel (b) Half-filled channel, and (c) Completely filled.

Figure 15. SEM image of channel cross-section.

Table 3. Microfluidic channel and their applications.

Author	Channel crosssection	Application
(Tiwari et al., 2020)	Rectangular	DNA analysis
(Ali et al., 2013)	Rectangular	Biomolecules detection
(Pinto et al., 2014)	Rectangular	Blood flow study
(Song et al., 2010)	Circular	CAPE Cell culture
(Choi et al., 2013)	Circular	Cell culture
(Abdelgawad et al., 2011)	Circular	Single cell traping

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