Abstract: 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 trans parent, 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: http://www.marketsandmarkets.com/PressReleases/microfluidics.asp Khosla, A. (2011).  Micropatternable multifunctional nanocomposite polymers for flexible soft MEMS applications  (Doctoral dissertation, Applied Science: School of Engineering Science). http://summit.sfu.ca/item/12017 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 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 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 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 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. 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. 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 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. 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. 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. 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. 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 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. 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. Figure 1

Abstract: Polymer MEMS/NEMS is a fast growing field with applications in lab on a chip (LOC), μTAS to new sensors and actuators to flexible micro-nano devices [1, 2,3]. While many polymers have been employed to realize flexible MEMS and microfluidic devices such as stated above, 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 [4,5,6,7, 8] . However, most devices based on PDMS or any kind of polymers are passive and, if active devices are fabricated, then they are bonded to substrates like glass which may contain active components like electrodes, heaters etc patterned on glass. This is because it has proven difficult to integrate, embed or pattern conducting lines, magnetic materials on PDMS because of the weak adhesion between PDMS and metals/alloys. In order to over come this problem, in past we had demonstrated fabrication of various PDMS based micropatternable nanocomposite polymers which are either electrically conductive and magnetic in nature [9, 10, 11, 12]. In this work we present an improved electrically and thermally conducuctive micropatternable PDMS based nanocomposite polymer containg milled carbon fibers, prepared by ultrasonically assisted processing technology. The prepared nanocomposite not only shows a better electrical and thermal conductivity cpmpared to previpusly reported work [13, 14,15,16, 17], but also negative temerate cofficient of resistivity (NTCR), making them as an ideal candidate for on chip μ-temperature sensors. Acknowledgements: Authors would like to thank Nippon Graphite Fiber Co., Ltd, Japan; for proving milled carbon fiber and technical support for this project. References: 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 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 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 Khosla, A. (2011).  Micropatternable multifunctional nanocomposite polymers for flexible soft MEMS applications  (Doctoral dissertation, Applied Science: School of Engineering Science). http://summit.sfu.ca/item/12017 Ozhikandathil, Jayan, Ajit Khosla, and Muthukumaran Packirisamy. "Electrically Conducting PDMS Nanocomposite Using In Situ Reduction of Gold Nanostructures and Mechanical Stimulation of Carbon Nanotubes and Silver Nanoparticles."  ECS Journal of Solid State Science and Technology  4.10 (2015): S3048-S3052. doi: 10.1149/2.0091510jss Packirisamy, Muthukumaran, Jayan Ozhikandathil, and Ajit Khosla. "Methods for fabricating morphologically transformed nano-structures (mtns) and tunable nanocomposite polymer materials, and devices using such materials." U.S. Patent Application No. 14/776,833. Daniel D. Hilbich ; Ajit Khosla ; Bonnie L. Gray ; Lesley Shannon; Bidirectional magnetic microactuators for uTAS. Proc. SPIE 7929, Microfluidics, BioMEMS, and Medical Microsystems IX, 79290H (February 14, 2011); doi:10.1117/12.875788. 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. 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. Ang Li ; Ajit Khosla ; Connie Drewbrook ; Bonnie L. Gray; Fabrication and testing of thermally responsive hydrogel-based actuators using polymer heater elements for flexible microvalves. Proc. SPIE 7929, Microfluidics, BioMEMS, and Medical Microsystems IX, 79290G (February 14, 2011); doi:10.1117/12.873197. 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 Gray, B. L., & Khosla, A. (2010).  Microfabrication and applications of nanoparticle doped conductive polymers  (pp. 227-262). McGraw Hill. Hesketh, Peter J., et al. "Conducting polymers and their applications."  Electrochemical Society Interface  (2012): 61. http://interface.ecsdl.org/content/21/3-4.toc.pdf Rahbar, Mona, Sam Seyfollahi, Ajit Khosla, Bonnie L. Gray, and Lesley Shannon. "Fabrication process for electromagnetic actuators compatible with polymer based microfluidic devices."  ECS Transactions  41, no. 20 (2012): 7-17. doi: 10.1149/1.3687433 Chung, D., et al. "Investigations of flexible Ag/AgCl nanocomposite polymer electrodes for suitability in tissue electrical impedance scanning (EIS)."  Journal of The Electrochemical Society  161.2 (2014): B3071-B3076. doi: 10.1149/2.018402jes Griffith, K.T., Ahmadizadeh, C., Huang, C., Pararameswaran, M.R., Young, J., Lee, C., Yang, T.O., Tam, C., Jin, Y., Jones, J. and Sjoerdsma, M., 2011, March. Multi-Walled Carbon Nanotube Doped Polydimethyalsiloxane Ribbon Cables for Flexible Microsystems. In  Meeting Abstracts  (No. 45, pp. 2080-2080). The Electrochemical Society. Khosla, Ajit, and Bonnie Lynne Gray. "Electrically conductive, thermosetting elastomeric material and uses therefor." U.S. Patent No. 8,557,385. 15 Oct. 2013. Figure 1

Abstract: In recent years, there has been a growing demand for safe soft robots that work in a work environment similar to that of humans. The use of 3D modeling technology in the manufacturing of soft robot chassis, soft electronic parts, and wiring processes is expected to lead to more efficient and smaller soft robot manufacturing. The objective of this study is to fabricate a gel capacitor using ionic liquid as an electrolyte, which has characteristics such as non-volatility, flame retardance, and conductivity. We fabricate ionic liquid gels that possess flexibility and conductivity after curing using a photoformable 3D gel printer, and discuss their performance as capacitors.

Abstract: We have fabricated GdBa 2 Cu 3 O y (GdBCO) jointed coated conductors (CCs) using a method in which intermediate grown superconductive (iGS) layers of (Y,Gd)Ba 2 Cu 3 O y ((Y,Gd)BCO) are formed from an YBa 2 Cu 3 O y precursor material to investigate their growth mechanism in the superconducting joint. We characterized the nanostructural evolution of the iGS layers by in-plane x-ray diffraction, transmission electron microscopy, and scanning transmission electron microscopy. The iGS layers contained Gd elements and were mainly composed of (Y,Gd)BCO grains. The c -axis oriented (Y,Gd)BCO grains nucleated on the GdBCO layers of both a joining strap and a CC. The thickness of the c -axis oriented (Y,Gd)BCO grains grew with time during the joining process at 800 °C, and finally both of the GdBCO layers were jointed together by the c -axis oriented (Y,Gd)BCO grains, resulting in a well-defined superconducting joint.