Over the past 30 years there has been a steady increase in interest in polymeric microfluidics and lab-on-a-chip technologies. The global microfluidics market is projected to reach USD 8.78 Billion by 2021 from USD 3.65 Billion in 2015, at a CAGR of 19.2% during the forecast period (2016 to 2021) [1]. While many polymers have been employed to realize microfluidic devices, polydimethylsiloxane (PDMS), a silicone based elastomer, has been widely used because of its biocompatibility, low cost, low toxicity, high oxidative and thermal stability, optical transparent, low permeability to water, low electrical conductivity, and ease of micropatterning [2,3, 4,5,6,7]. However, microfabrication of PDMS based microfluidic devices involves fabrication of micromolds which need expenisve infrastruce, such as clean room, photolithography equipment, masks etc. [8, 9, 10, 11, 12, 13]. Previously we had presented 3-D printing of complex MEMS structures [14] and other devices [15,16]. In this paper, we present fabrication of microfluidic molds and devices by employing 3D printing technology that are otherwise time consuming and difficult to manufacture with state of the art 2-D MEMS fabrication technology. Figure 1 shows optical micrograph of 3D printed micromold channels.

References:

1. http://www.marketsandmarkets.com/PressReleases/microfluidics.asp
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3. A. Khosla, B.L. Gray, Preparation, characterization and micromolding of multi-walled carbon nanotube polydimethylsiloxane conducting nanocomposite polymer, Materials Letters, Volume 63, Issues 13–14, 31 May 2009, Pages 1203-1206, ISSN 0167-577X, http://doi.org/10.1016/j.matlet.2009.02.043
4. Khosla, Ajit. "Nanoparticle-doped electrically-conducting polymers for flexible nano-micro Systems." The Electrochemical Society Interface 21.3-4 (2012): 67-70. doi: 10.1149/2.F04123-4if
5. Khosla, A. and Gray, B. L. (2010), Preparation, Micro-Patterning and Electrical Characterization of Functionalized Carbon-Nanotube Polydimethylsiloxane Nanocomposite Polymer. Macromol. Symp., 297: 210–218. doi:10.1002/masy.200900165
6. Khosla, Ajit, and Bonnie L. Gray. "(Invited) Micropatternable Multifunctional Nanocomposite Polymers for Flexible Soft NEMS and MEMS Applications." ECS Transactions 45.3 (2012): 477-494. doi: 10.1149/1.3700913
7. A. Khosla ; B. L. Gray; New technologies for large-scale micropatterning of functional nanocomposite polymers. Proc. SPIE 8344, Nanosensors, Biosensors, and Info-Tech Sensors and Systems 2012, 83440W (April 26, 2012); doi:10.1117/12.915178.
8. Khosla, Ajit. "Etch Rate Characterization of PMMA Via CO2 Laser for Hybrid Micromolding Process." In Meeting Abstracts, no. 11, pp. 691-691. The Electrochemical Society, 2014.
9. Rahbar, Mona, et al. "Fabrication process for electromagnetic actuators compatible with polymer based microfluidic devices." ECS Transactions 41.20 (2012): 7-17. doi: 10.1149/1.3687433
10. D. Hilbich ; A. Rahbar ; A. Khosla ; B. L. Gray; Manipulation of permanent magnetic polymer micro-robots: a new approach towards guided wireless capsule endoscopy. Proc. SPIE 8548, Nanosystems in Engineering and Medicine, 85482I (October 24, 2012); doi:10.1117/12.979250.
11. A. Khosla ; B. L. Gray; New technologies for large-scale micropatterning of functional nanocomposite polymers. Proc. SPIE 8344, Nanosensors, Biosensors, and Info-Tech Sensors and Systems 2012, 83440W (April 26, 2012); doi:10.1117/12.915178.
12. A. Khosla ; J. L. Korčok ; B. L. Gray ; D. B. Leznoff ; J. W. Herchenroeder ; D. Miller ; Z. Chen; Fabrication and testing of integrated permanent micromagnets for microfluidic systems. Proc. SPIE 7593, Microfluidics, BioMEMS, and Medical Microsystems VIII, 759316 (February 17, 2010); doi:10.1117/12.840942.
13. A. Khosla ; B. L. Gray; Fabrication of multiwalled carbon nanotube polydimethylsiloxne nanocomposite polymer flexible microelectrodes for microfluidics and MEMS. Proc. SPIE 7642, Electroactive Polymer Actuators and Devices (EAPAD) 2010, 76421V (April 09, 2010); doi:10.1117/12.847292.
14. Khosla, A. 3-D Printed Polymer MEMS, PRiME 2016/230th ECS Meeting (October 2-7, 2016), 2016. http://ma.ecsdl.org/content/MA2016-02/51/3861.abstract
15. Kei Sato ; Samiul Basher ; Takafumi Ota ; Taishi Tase ; Kyuichiro Takamatsu ; Azusa Saito ; Ajit Khosla ; Masaru Kawakami ; Hidemitsu Furuawa; Development of low-cost open source 3D gel printer "RepRap SWIM-ER". Proc. SPIE 10167, Nanosensors, Biosensors, Info-Tech Sensors and 3D Systems 2017, 101670B (April 17, 2017); doi:10.1117/12.2257628.
16. Masato Makino ; Azusa Saito ; Mai Kodama ; Kyuuichiro Takamatsu ; Hideaki Tamate ; Kazuyuki Sakai ; Masato Wada ; Ajit Khosla ; Masaru Kawakami ; Hidemitsu Furukawa; 3D printing in social education: Eki-Fab and student PBL. Proc. SPIE 10167, Nanosensors, Biosensors, Info-Tech Sensors and 3D Systems 2017, 101670W (April 17, 2017); doi:10.1117/12.2265037.