Microfluidic chips have been widely used; however, traditional manufacturing methods struggle to meet the demands of low-cost and large-scale production. In particular, the preparation of microfluidic chip molds primarily employs silicon wafers and glass substrates, with limited attention being paid to polymer substrates. In this study, an SAF2100 photosensitive dry film was used to prepare microfluidic chip molds with different aspect ratios on polycarbonate (PC) surfaces. The weak adhesion between the dry film and the PC substrate was improved by a 3-mercaptopropyltrimethoxysilane (MPTMS) solution, and the problem of difficult peeling between the dry film and polydimethylsiloxane (PDMS) was enhanced by a trichloro(1H,1H,2H,2H-perfluorooctyl) silane (PFOCTS) solution. Initially, a single layer (100 μm) of dry film was stacked by lamination, and the effects of lamination temperature and lamination frequency on bond strength were investigated. The optimal parameters for temperature and lamination were 95 °C and four laminations, respectively. Subsequently, the exposure time parameters of the dry film were studied, and the optimal exposure times (OETs) for 1–5 layers of the dry film were determined using the edge sharpness value method, with the results being 20, 60, 50, 110, and 110 s, respectively. Next, the effect of dry film thickness after lamination is discussed. The results indicated that fewer dry film layers resulted in greater thickness variation after lamination. Specifically, the final thickness of a single layer of dry film after lamination was (96.2 ± 0.2) μm, and the final thickness of five layers of dry film after lamination was (500 ± 0.09) μm. The bonding strength between the dry film and the PC substrate was improved through surface grafting. The bonding strength increased from 25.53 kPa to 89.37 kPa after treatment. Increasing the grafting time also affects the bonding strength, with the bonding strength increasing from 11.51 kPa to 121.14 kPa after 5 min of grafting. After the development, the dry film surface was modified using PFOCTS. After modification, the water contact angle increased from 73.87° ± 3.48° to 122.83° ± 4.02°. After casting PDMS of equal mass, the peel force was measured, and the bond strength was significantly reduced after the surface treatment. Finally, the peeled microfluidic channels were bonded to form a microfluidic chip, and the channel sealing and droplet generation performances were verified. This study provides a reference for the preparation of high-aspect-ratio microfluidic chips for low-cost, large-scale production.
| [1] |
Pattanayak P, Singh SK, Gulati M, et al.Microfluidic chips: recent advances, critical strategies in design, applications and future perspectives. Microfluid Nanofluid, 2021, 25(12): 99.
|
| [2] |
Whitesides GM. The origins and the future of microfluidics. Nature, 2006, 442(7101):368-373.
|
| [3] |
Zhu PA, Wang LQ. Passive and active droplet generation with microfluidics: a review. Lab Chip, 2017, 17(1): 34-75.
|
| [4] |
Wat JKM, Xu M, Nan L, et al.Rapid antimicrobial susceptibility tests performed by self-diluting microfluidic chips for drug resistance studies and point-of-care diagnostics. Microsyst Nanoeng, 2025, 11(1): 110.
|
| [5] |
Quintard C, Tubbs E, Jonsson G, et al.A microfluidic platform integrating functional vascularized organoids-on-chip. Nat Commun, 2024, 15(1):1452.
|
| [6] |
Sathishkumar N, Valenzuela JGC, Le NH, et al.A combined digital microfluidic test for assessing infection and immunity status for viral disease in saliva. Lab Chip, 2025, 25(13):3197-3207.
|
| [7] |
Yue T, Zhao D, Phan DTT, et al.A modular microfluidic system based on a multilayered configuration to generate large-scale perfusable microvascular networks. Microsyst Nanoeng, 2021, 7(1): 4.
|
| [8] |
Khalaf EM, Jabbar HS, Romero-Parra RM, et al.Smartphone-assisted microfluidic sensor as an intelligent device for on-site determination of food contaminants: developments and applications. Microchem J, 2023, 190108692
|
| [9] |
Pol R, Céspedes F, Gabriel D, et al.Microfluidic lab-on-a-chip platforms for environmental monitoring. Trac-Trend Anal Chem, 2017, 95: 62-68.
|
| [10] |
Jokerst JC, Emory JM, Henry CS. Advances in microfluidics for environmental analysis. Analyst, 2012, 137(1): 24-34.
|
| [11] |
Alghannam F, Alayed M, Alfihed S, et al.Recent progress in PDMS-based microfluidics toward integrated organ-on-a-chip biosensors and personalized medicine. Biosensors-Basel, 2025, 15(2): 76.
|
| [12] |
Ren KN, Zhou JH, Wu HK. Materials for microfluidic chip fabrication. Accounts Chem Res, 2013, 46(11):2396-2406.
|
| [13] |
Modarelli MJC, Kot-Thompson DM, Hoshino K. 5-Axis CNC micro-milling machine for three-dimensional microfluidics. Lab Chip, 2025, 25(2): 127-142.
|
| [14] |
Guckenberger DJ, De Groot TE, Wan AMD, et al.Micromilling: a method for ultra-rapid prototyping of plastic microfluidic devices. Lab Chip, 2015, 15(11): 2364-2378.
|
| [15] |
Weisgrab G, Ovsianikov A, Costa PF. Functional 3D printing for microfluidic chips. Adv Mater Technol-US, 2019, 4(10): 1900275.
|
| [16] |
Fu E, Wentland L. A survey of 3D printing technology applied to paper microfluidics. Lab Chip, 2021, 22(1):9-25.
|
| [17] |
Bhattacharjee N, Urrios A, Kang S, et al.The upcoming 3D-printing revolution in microfluidics. Lab Chip, 2016, 16(10): 1720-1742.
|
| [18] |
Rogers JA, Nuzzo RG. Recent progress in soft lithography. Mater Today, 2005, 8(2): 50-56.
|
| [19] |
Zhao BS, Wu WQ, Zhou MY, et al.Highly dynamic tempered in-mold thermocompression bonding of microfluidic chips: process characteristics and bonding performances. J Mater Res Technol, 2023, 24: 639-652.
|
| [20] |
Madhankumar P, Sujatha L, Sundar R, et al.Fabrication of low-cost MEMS microfluidic devices using metal embossing technique on glass for lab-on-chip applications. J Micromech Microeng, 2023, 33(8084001
|
| [21] |
Attia UM, Marson S, Alcock JR. Micro-injection moulding of polymer microfluidic devices. Microfluid Nanofluid, 2009, 7(1): 1-28.
|
| [22] |
Menezes PD, Hunter A, Dickson T, et al.Scalable, transparent, and micro: 3D-printed rapid tooling for injection molded microfluidics. Adv Eng Mater, 2024, 26(20): 2400276.
|
| [23] |
Abgrall P, Conedera V, Camon H, et al.SU-8 as a structural material for labs-on-chips and microelectromechanical systems. Electrophoresis, 2007, 2824):4539-4551.
|
| [24] |
Lee JB, Choi KH, Yoo K. Innovative SU-8 lithography techniques and their applications. Micromachines-Basel, 2015, 6(1): 1-18.
|
| [25] |
Ng JMK, Gitlin I, Stroock AD, et al.Components for integrated poly(dimethylsiloxane) microfluidic systems. Electrophoresis, 2002, 23(20): 3461-3473.
|
| [26] |
Steigert J, Brett O, Müller C, et al.A versatile and flexible low-temperature full-wafer bonding process of monolithic 3D microfluidic structures in SU-8. J Micromech Microeng, 2008, 18(9095013
|
| [27] |
Dervisevic E, Voelcker NH, Risbridger G, et al.High-aspect-ratio SU-8-based optofluidic device for ammonia detection in cell culture media. ACS Sensors, 2020, 5(8): 2523-2529.
|
| [28] |
Cho Y, Cho Y. Simultaneous generation of monodisperse droplets with two different sizes using microchannel array with asymmetric high-aspect-ratio cross-section. Int J Precis Eng Man, 2025, 26(6): 1541-1547.
|
| [29] |
Zhou J, Giridhar PV, Kasper S, et al.Modulation of aspect ratio for complete separation in an inertial microfluidic channel. Lab Chip, 2013, 13(10): 1919-1929.
|
| [30] |
Niculescu AG, Chircov C, Bîrca AC, et al.Fabrication and applications of microfluidic devices: a review. Int J Mol Sci, 2021, 22(4): 2011.
|
| [31] |
Kung YC, Huang KW, Fan YJ, Chiou PY. Fabrication of 3D high aspect ratio PDMS microfluidic networks with a hybrid stamp. Lab Chip, 2015, 158):1861-1868.
|
| [32] |
Javidanbardan A, Azevedo AM, Chu V, et al.A systematic approach for developing 3D high-quality pdms microfluidic chips based on micromilling technology. Micromachines-Basel, 2022, 13(1): 6.
|
| [33] |
Chen CP, Mehl BT, Munshi AS, et al.3D-printed microfluidic devices: fabrication, advantages and limitations—a mini review. Anal Methods-UK, 2016, 8(31):6005-6012.
|
| [34] |
Waheed S, Cabot JM, Macdonald NP, et al.3D printed microfluidic devices: enablers and barriers. Lab Chip, 2016, 16(11): 1993-2013.
|
| [35] |
Stephan K, Pittet P, Renaud L, et al.Fast prototyping using a dry film photoresist: microfabrication of soft-lithography masters for microfluidic structures. J Micromech Microeng, 2007, 17(10): 69-74.
|
| [36] |
Courson R, Cargou S, Conedera V, et al.Low-cost multilevel microchannel lab on chip: DF-1000 series dry film photoresist as a promising enabler. RSC Adv, 2014, 4(97): 54847-54853.
|
| [37] |
Chung CK, Hong YZ. Fabrication and analysis of the reflowed microlens arrays using JSR THB-130 N photoresist with different heat treatments. Microsyst Technol, 2007, 13(5/6): 523-530.
|
| [38] |
Azizy R, Otto H, König J, et al.A microfluidic magnetohydrodynamic pump based on a thermally bonded composite of glass and dry film photoresist. Micro Nano Eng, 2023, 18100173
|
| [39] |
Stöhr U, Vulto P, Hoppe P, et al.High-resolution permanent photoresist laminate for microsystem applications. J Micro-Nanolith Mem, 2008, 7(3033009
|
| [40] |
Wangler N, Beck S, Ahrens G, et al.Ultra thick epoxy-based dry-film resist for high aspect ratios. Microelectron Eng, 2012, 97: 92-95.
|
| [41] |
El Hasni A, Pfirrmann S, Kolander A, et al.Six-layer lamination of a new dry film negative-tone photoresist for fabricating complex 3D microfluidic devices. Microfluid Nanofluid, 2017, 21(3): 41.
|
| [42] |
Khalkhal F, Chaney KH, Muller SJ. Optimization and application of dry film photoresist for rapid fabrication of high-aspect-ratio microfluidic devices. Microfluid Nanofluid, 2016, 2011):153.
|
| [43] |
Shakeri A, Khan S, Didar TF. Conventional and emerging strategies for the fabrication and functionalization of PDMS-based microfluidic devices. Lab Chip, 2021, 21(16):3053-3075.
|
| [44] |
Sivakumar R, Lee NY. Microfluidic device fabrication mediated by surface chemical bonding. Analyst, 2020, 145(12): 4096-4110.
|
| [45] |
Herth E, Zeggari R, Rauch JY, et al.Investigation of amorphous SiOx layer on gold surface for surface plasmon resonance measurements. Microelectron Eng, 2016, 163: 43-48.
|
| [46] |
Smith BC (2022) Infrared spectroscopy of polymers, IX: pendant ester polymers and polycarbonates. Spectroscopy 37(11):16−19. https://doi.org/10.56530/spectroscopy.xn9369p8
|
| [47] |
Tseng YT, Lu HY, Li JR, et al.Facile functionalization of polymer surfaces in aqueous and polar organic solvents via 3-mercaptopropylsilatrane. ACS Appl Mater Inter, 2016, 8(49): 34159-34169.
|
Funding
National Natural Science Foundation of China(62373235)
Shanghai Science and Technology Committee Natural Science Foundation(23ZR1423700)
Shanghai municipal education innovation project(2021-09-E00113)
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