Dr. Navid Kashaninejad received his Ph.D. in microfluidics under the supervision of Professor Nam-Trung Nguyen from the Division of Thermal and Fluid Engineering, Nanyang Technological University (NTU), Singapore. His research interests include design, fabrication and numerical simulation of microfluidic platforms for cancer studies, organ-on-a-chip devices; and tissue engineering and regenerative medicine (e.g., fabrication of biomimetic scaffolds). His awards include being selected as a distinguished scientist from Iran’s National Elites Foundation (INEF), plus being granted a full scholarship from INEF to pursue postdoctoral research at Sharif University of Technology (Iran). He was also awarded a SINGA scholarship from the Singapore Agency for Science, Research and Technology (A*STAR) to pursue Ph.D. studies at NTU. He has received two more grants from Iran’s Cancer Biology Research Centre and Tabriz University of Medical Sciences (~$75,000) to design and fabricate microfluidic platforms in personalized cancer medicine. He is now a postdoctoral research associate working jointly with Prof. Jin (from the School of Mathematical and Physical Sciences) and Dr. Warkiani (from the Faculty of Engineering and IT) at UTS.
Barisam, M, Saidi, MS, Kashaninejad, N & Nguyen, NT 2018, 'Prediction of necrotic core and hypoxic zone of multicellular spheroids in a microbioreactor with a U-shaped barrier', Micromachines, vol. 9, no. 3.View/Download from: Publisher's site
© 2018 by the authors. Microfluidic devices have been widely used for biological and cellular studies. Microbioreactors for three-dimensional (3D) multicellular spheroid culture are now considered as the next generation in in vitro diagnostic tools. The feasibility of using 3D cell aggregates to form multicellular spheroids in a microbioreactor with U-shaped barriers has been demonstrated experimentally. A barrier array is an alternative to commonly used microwell traps. The present study investigates oxygen and glucose concentration distributions as key parameters in a U-shaped array microbioreactor using finite element simulation. The effect of spheroid diameter, inlet concentration and flow rate of the medium are systematically studied. In all cases, the channel walls are considered to be permeable to oxygen. Necrotic and hypoxic or quiescent regions corresponding to both oxygen and glucose concentration distributions are identified for various conditions. The results show that the entire quiescent and necrotic regions become larger with increasing spheroid diameter and decreasing inlet and wall concentration. The shear stress (0.5-9 mPa) imposed on the spheroid surface by the fluid flow was compared with the critical values to predict possible damage to the cells. Finally, optimum range of medium inlet concentration (0.13-0.2 mM for oxygen and 3-11 mM for glucose) and flow rate (5-20 L/min) are found to form the largest possible multicellular spheroid (500 m), without any quiescent and necrotic regions with an acceptable shear stress. The effect of cell-trap types on the oxygen and glucose concentration inside the spheroid was also investigated. The levels of oxygen and glucose concentration for the microwell are much lower than those for the other two traps. The U-shaped barrier created with microposts allows for a continuous flow of culture medium, and so improves the glucose concentration compared to that in the integrated U-shaped barrier. Oxygen concen...
Dinh, T, Phan, HP, Kashaninejad, N, Nguyen, TK, Dao, DV & Nguyen, NT 2018, 'An On-Chip SiC MEMS Device with Integrated Heating, Sensing, and Microfluidic Cooling Systems', Advanced Materials Interfaces, vol. 5.View/Download from: UTS OPUS or Publisher's site
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim There has been increasing interest in electronic systems with integrated microfluidic active cooling modules. However, the failure of 3C-SiC/Si interface with increasing temperature has prevented the development of 3C-SiC power electronic devices. Here, all integrated transparent heating, sensing, and cooling systems are developed on a single silicon carbide (SiC) chip for efficient thermal management. SiC nanofilms are grown on a silicon wafer, are transferred to a glass substrate, and then a micro electromechanical system process is employed to fabricate a SiC-on-glass system with integrated heaters and temperature sensors. A cooling system is fabricated with microchannel using 3D printing, molding, and plasma assisted bonding. The thermal management of the SiC-based system shows an excellent capability of heating and detecting temperature as well as effective cooling with an efficiency of from 0.24 to 0.28 and a maximum cooling rate of 0.1 K(µL min1)1. The fabrication strategy can be utilized for large production of SiC power nanoelectronics with high efficiency of integrated thermal management systems.
Moghadas, H, Saidi, MS, Kashaninejad, N & Nguyen, N-T 2018, 'A high-performance polydimethylsiloxane electrospun membrane for cell culture in lab-on-a-chip.', Biomicrofluidics, vol. 12, no. 2, p. 024117.View/Download from: Publisher's site
Thin porous membranes are important components in a microfluidic device, serving as separators, filters, and scaffolds for cell culture. However, the fabrication and the integration of these membranes possess many challenges, which restrict their widespread applications. This paper reports a facile technique to fabricate robust membrane-embedded microfluidic devices. We integrated an electrospun membrane into a polydimethylsiloxane (PDMS) device using the simple plasma-activated bonding technique. To increase the flexibility of the membrane and to address the leakage problem, the electrospun membrane was fabricated with the highest weight ratio of PDMS to polymethylmethacrylate (i.e., 6:1 w/w). The membrane-integrated microfluidic device could withstand a flow rate of up to 50l/min. As a proof of concept, we demonstrated that such a compartmentalized microfluidic platform could be successfully used for cell culture with the capability of providing a more realistic in vivo-like condition. Human lung cancer epithelial cells (A549) were seeded on the membrane from the top microchannel, while the continuous flow of the culture medium through the bottom microchannel provided a shear-free cell culture condition. The tortuous micro-/nanofibers of the membrane immobilized the cells within the hydrophobic micropores and with no need of extracellular matrix for cell adhesion and cell growth. The hydrophobic surface conditions of the membrane were suitable for anchorage-independent cell types. To further extend the application of the device, we qualitatively showed that rinsing the membrane with ethanol prior to cell seeding could temporarily render the membrane hydrophilic and the platform could also be used for anchorage-dependent cells. Due to the three-dimensional (3D) topography of the membranes, three different configurations were observed, including individual single cells, monolayer cells, and 3D cell clusters. This cost-effective and robust compartmentalized micr...
Moghadas, H, Saidi, MS, Kashaninejad, N & Nguyen, N-T 2018, 'Challenge in particle delivery to cells in a microfluidic device.', Drug delivery and translational research, vol. 8, no. 3, pp. 830-842.View/Download from: UTS OPUS or Publisher's site
Micro and nanotechnology can potentially revolutionize drug delivery systems. Novel microfluidic systems have been employed for the cell culture applications and drug delivery by micro and nanocarriers. Cells in the microchannels are under static and dynamic flow perfusion of culture media that provides nutrition and removes waste from the cells. This exerts hydrostatic and hydrodynamic forces on the cells. These forces can considerably affect the functions of the living cells. In this paper, we simulated the flow of air, culture medium, and the particle transport and deposition in the microchannels under different angles of connection inlet. It was found that the shear stress induced by the medium culture flow is not so high to damage the cells and that it is roughly uniform in the cell culture section (CCS). However, the local shear stresses in the other parts of the microchip differ by changing the angles of the connection inlet. The results showed that the particle deposition was a function of the particle size, the properties of the fluid, and the flow rate. At a lower air flow rate, both small and large particles deposited in the entrance region and none of them reached the CCS. Once the airflow rate increased, the drag of the flow could overcome the diffusion of the small particles and deliver them to the CCS so that more than 88% of the 100 nm and 98% of the 200 nm particles deposited in the CCS. However, larger particles with average diameters in micrometers could not reach the CCS by the airflow even at high flow rate. In contrast, our findings indicated that both small and large particles could be delivered to the CCS by liquid flow. Our experimental data confirm that microparticles (with diameters of 5 and 20 m) suspended in a liquid can reach the CCS at a well-adjusted flow rate. Consequently, a liquid carrier is suggested to transport large particles through microchannels. As a powerful tool, these numerical simulations provide a nearly complete un...
Moshksayan, K, Kashaninejad, N, Warkiani, ME, Lock, JG, Moghadas, H, Firoozabadi, B, Saidi, MS & Nguyen, NT 2018, 'Spheroids-on-a-chip: Recent advances and design considerations in microfluidic platforms for spheroid formation and culture', Sensors and Actuators, B: Chemical, vol. 263, pp. 151-176.View/Download from: Publisher's site
© 2018 Elsevier B.V. A cell spheroid is a three-dimensional (3D) aggregation of cells. Synthetic, in-vitro spheroids provide similar metabolism, proliferation, and species concentration gradients to those found in-vivo. For instance, cancer cell spheroids have been demonstrated to mimic in-vivo tumor microenvironments, and are thus suitable for in-vitro drug screening. The first part of this paper discusses the latest microfluidic designs for spheroid formation and culture, comparing their strategies and efficacy. The most recent microfluidic techniques for spheroid formation utilize emulsion, microwells, U-shaped microstructures, or digital microfluidics. The engineering aspects underpinning spheroid formation in these microfluidic devices are therefore considered. In the second part of this paper, design considerations for microfluidic spheroid formation chips and microfluidic spheroid culture chips (SFCs and SCCs) are evaluated with regard to key parameters affecting spheroid formation, including shear stress, spheroid diameter, culture medium delivery and flow rate. This review is intended to benefit the microfluidics community by contributing to improved design and engineering of microfluidic chips capable of forming and/or culturing three-dimensional cell spheroids.
Barisam, M, Saidi, MS, Kashaninejad, N, Vadivelu, R & Nguyen, NT 2017, 'Numerical simulation of the behavior of toroidal and spheroidal multicellular aggregates in microfluidic devices with microwell and U-shaped barrier', Micromachines, vol. 8, no. 12, pp. 1-16.View/Download from: UTS OPUS or Publisher's site
© 2017 by the authors. A microfluidic system provides an excellent platform for cellular studies. Most importantly, a three-dimensional (3D) cell culture model reconstructs more accurately the in vivo microenvironment of tissue. Accordingly, microfluidic 3D cell culture devices could be ideal candidates for in vitro cell culture platforms. In this paper, two types of 3D cellular aggregates, i.e., toroid and spheroid, are numerically studied. The studies are carried out for microfluidic systems containing U-shaped barrier as well as microwell structure. For the first time, we obtain oxygen and glucose concentration distributions inside a toroid aggregate as well as the shear stress on its surface and compare its performance with a spheroid aggregate of the same volume. In particular, we obtain the oxygen concentration distributions in three areas, namely, oxygen-permeable layer, multicellular aggregates and culture medium. Further, glucose concentration distributions in two regions of multicellular aggregates and culture medium are investigated. The results show that the levels of oxygen and glucose in the system containing U-shaped barriers are far more than those in the system containing microwells. Therefore, to achieve high levels of oxygen and nutrients, a system with U-shaped barriers is more suited than the conventional traps, but the choice between toroid and spheroid depends on their volume and orientation. The results indicate that higher oxygen and glucose concentrations can be achieved in spheroid with a small volume as well as in horizontal toroid with a large volume. The vertical toroid has the highest levels of oxygen and glucose concentration while the surface shear stress on its surface is also maximum. These findings can be used as guidelines for designing an optimum 3D microfluidic bioreactor based on the desired levels of oxygen, glucose and shear stress distributions.
Moghadas, H, Saidi, MS, Kashaninejad, N, Kiyoumarsioskouei, A & Nguyen, N-T 2017, 'Fabrication and characterization of low-cost, bead-free, durable and hydrophobic electrospun membrane for 3D cell culture.', Biomedical Microdevices, vol. 19, no. 4, pp. 1-9.View/Download from: UTS OPUS or Publisher's site
This paper reports the fabrication of electrospun polydimethylsiloxane (PDMS) membranes/scaffolds that are suitable for three-dimensional (3D) cell culture. Through modification the ratio between PDMS and polymethylmethacrylate (PMMA) as carrier polymer, we report the possibility of increasing PDMS weight ratio of up to 6 for electrospinning. Increasing the PDMS content increases the fiber diameter, the pore size, and the hydrophobicity. To our best knowledge, this is the first report describing beads-free, durable and portable electrospun membrane with maximum content of PDMS suitable for cell culture applications. To show the proof-of-concept, we successfully cultured epithelial lung cancer cells on these membranes in a static well plate without surface modification. Surprisingly, due to three-dimensional (3D) and hydrophobic nature of the electrospun fibers, cells aggregated into 3D multicellular spheroids. These easily detachable and cost-effective scaffolds with controllable thicknesses and high tensile strength are good candidates for cell-stretching devices, organ-on-a-chip devices, tissue engineering and studies of non-adherent mammalian cancer stem cells.
Nguyen, NT, Hejazian, M, Ooi, CH & Kashaninejad, N 2017, 'Recent advances and future perspectives on microfluidic liquid handling', Micromachines, vol. 8, no. 6, pp. 1-20.View/Download from: UTS OPUS or Publisher's site
© 2017 by the authors. The interdisciplinary research field of microfluidics has the potential to revolutionize current technologies that require the handling of a small amount of fluid, a fast response, low costs and automation. Microfluidic platforms that handle small amounts of liquid have been categorised as continuous-flow microfluidics and digital microfluidics. The first part of this paper discusses the recent advances of the two main and opposing applications of liquid handling in continuous-flow microfluidics: mixing and separation. Mixing and separation are essential steps in most lab-on-a-chip platforms, as sample preparation and detection are required for a variety of biological and chemical assays. The second part discusses the various digital microfluidic strategies, based on droplets and liquid marbles, for the manipulation of discrete microdroplets. More advanced digital microfluidic devices combining electrowetting with other techniques are also introduced. The applications of the emerging field of liquid-marble-based digital microfluidics are also highlighted. Finally, future perspectives on microfluidic liquid handling are discussed.
Kashaninejad, N, Nikmaneshi, MR, Moghadas, H, Oskouei, AK, Rismanian, M, Barisam, M, Saidi, MS & Firoozabadi, B 2016, 'Organ-tumor-on-a-chip for chemosensitivity assay: A critical review', Micromachines, vol. 7, no. 8.View/Download from: Publisher's site
© 2016 by the authors. With a mortality rate over 580,000 per year, cancer is still one of the leading causes of death worldwide. However, the emerging field of microfluidics can potentially shed light on this puzzling disease. Unique characteristics of microfluidic chips (also known as micro-total analysis system) make them excellent candidates for biological applications. The ex vivo approach of tumor-on-a-chip is becoming an indispensable part of personalized medicine and can replace in vivo animal testing as well as conventional in vitro methods. In tumor-on-a-chip, the complex three-dimensional (3D) nature of malignant tumor is co-cultured on a microfluidic chip and high throughput screening tools to evaluate the efficacy of anticancer drugs are integrated on the same chip. In this article, we critically review the cutting edge advances in this field and mainly categorize each tumor-on-a-chip work based on its primary organ. Specifically, design, fabrication and characterization of tumor microenvironment; cell culture technique; transferring mechanism of cultured cells into the microchip; concentration gradient generators for drug delivery; in vitro screening assays of drug efficacy; and pros and cons of each microfluidic platform used in the recent literature will be discussed separately for the tumor of following organs: (1) Lung; (2) Bone marrow; (3) Brain; (4) Breast; (5) Urinary system (kidney, bladder and prostate); (6) Intestine; and (7) Liver. By comparing these microchips, we intend to demonstrate the unique design considerations of each tumor-on-a-chip based on primary organ, e.g., how microfluidic platform of lung-tumor-on-a-chip may differ from liver-tumor-on-a-chip. In addition, the importance of heart-liver-intestine co-culture with microvasculature in tumor-on-a-chip devices for in vitro chemosensitivity assay will be discussed. Such system would be able to completely evaluate the absorption, distribution, metabolism, excretion and toxicity (A...
This paper presents analytical modeling of slip liquid flow in parallel-plate microchannels, and can be divided in two parts. In the first part, classical relationships describing velocity, flow rate, pressure gradient, and shear stress are extended to the more general cases where there exist two different values of the yet-unknown slip lengths at the top and bottom walls of the channel. These formulations can be used to experimentally determine the values of slip length on the channels fabricated from two different hydrophobic walls. In the second part, the emphasis is given on the quantification of the slip length analytically. Generating mechanism of slip is attributed to the existence of a low-viscosity region between the liquid and the solid surface. By extending the previous works, the analytical values of slip length are determined using exact, rather than empirical, values of air gap thickness at different ranges of air flow Knudsen number. In addition to the exact expressions of air gap thickness, the corresponding ranges of the channel height where slip flow can be induced are also found analytically. It is found that when the channel height is larger than 700 m, air flow is in continuum regime and no-slip boundary condition can be used. For the case where the channels height is smaller than 700 m, and larger than 7.5 m, slip boundary condition should be used to model the air flow in the channel. Finally, for the channel with the height smaller than 7.5 m, Navier-Stokes equation cannot be used to model the air flow, and instead molecularbased approaches should be implemented. The results of this paper can be used as a guideline for both experimentalists and theoreticians to study the slip flow in parallel-plate microchannels. © 2013 Bentham Science Publishers.
Kashaninejad, N, Nguyen, NT & Chan, WK 2013, 'The three-phase contact line shape and eccentricity effect of anisotropic wetting on hydrophobic surfaces', Soft Matter, vol. 9, no. 2, pp. 527-535.View/Download from: Publisher's site
This paper experimentally evaluates the combined effects of eccentricity, relative spacing, and viewing directions on the wetting conditions and the three-phase contact line shapes of hydrophobic surfaces patterned with discrete micropillars. Different techniques to depict the tortuosity of the contact line between the water droplet and microstructured surfaces are presented. First, square micropillars with different values of normalized eccentricity, *, and relative spacing, D*, were fabricated using a double casting replication technique. Subsequently, the contact angles were measured along different viewing angles by gradually rotating the sample from 0° to 180°. The contact angle distribution was found as a periodic function of the viewing angle whose period depends on the micropillar eccentricity. The results showed that anisotropy increases by increasing the micropillar eccentricity or decreasing the pillar relative spacing. However, the effect of changing the micropillar eccentricity was much more pronounced. Micropillars with * = 0.75 and smaller D* showed maximum degrees of anisotropic wetting and droplet distortion corresponding to 7% and 15%, respectively. Using the measured droplet aspect ratio, corrugated shapes of the three-phase contact line of the micropillars were also reconstructed. Finally, a simple yet effective semi-analytical model, based on Fourier series curve-fitting of the experimental data, was developed to describe the equilibrium 3D shape of the droplet on anisotropic surfaces. Experimental and simulation results reveal that the degrees of anisotropic wetting and droplet distortion were directly proportional to the energy barriers of the system, resulting from the noncircular corrugated shape of the three-phase contact line. The obtained results may further shed light on the underlying mechanism influencing anisotropic wetting on micropatterned surfaces. © The Royal Society of Chemistry 2013.
Nguyen, N-T, Shaegh, SAM, Kashaninejad, N & Phan, D-T 2013, 'Design, fabrication and characterization of drug delivery systems based on lab-on-a-chip technology.', Advanced drug delivery reviews, vol. 65, no. 11-12, pp. 1403-1419.View/Download from: Publisher's site
Lab-on-a-chip technology is an emerging field evolving from the recent advances of micro- and nanotechnologies. The technology allows the integration of various components into a single microdevice. Microfluidics, the science and engineering of fluid flow in microscale, is the enabling underlying concept for lab-on-a-chip technology. The present paper reviews the design, fabrication and characterization of drug delivery systems based on this amazing technology. The systems are categorized and discussed according to the scales at which the drug is administered. Starting with the fundamentals on scaling laws of mass transfer and basic fabrication techniques, the paper reviews and discusses drug delivery devices for cellular, tissue and organism levels. At the cellular level, a concentration gradient generator integrated with a cell culture platform is the main drug delivery scheme of interest. At the tissue level, the synthesis of smart particles as drug carriers using lab-on-a-chip technology is the main focus of recent developments. At the organism level, microneedles and implantable devices with fluid-handling components are the main drug delivery systems. For drug delivery to a small organism that can fit into a microchip, devices similar to those of cellular level can be used.
Sanaye, S, Dehghandokht, M, Kashaninejad, N & Fartaj, A 2013, 'Corrigendum "Temperature control of a cabin in an automobile using thermal modeling and fuzzy controller" [Applied Energy 97 (2) (2012) 860-868]', Applied Energy, vol. 103, p. 721.View/Download from: Publisher's site
Kashaninejad, N, Chan, WK & Nguyen, N-T 2012, 'Eccentricity effect of micropatterned surface on contact angle.', Langmuir : the ACS journal of surfaces and colloids, vol. 28, no. 10, pp. 4793-4799.View/Download from: Publisher's site
This article experimentally shows that the wetting property of a micropatterned surface is a function of the center-to-center offset distance between successive pillars in a column, referred to here as eccentricity. Studies were conducted on square micropatterns which were fabricated on a silicon wafer with pillar eccentricity ranging from 0 to 6 m for two different pillar diameters and spacing. Measurement results of the static as well as the dynamic contact angles on these surfaces revealed that the contact angle decreases with increasing eccentricity and increasing relative spacing between the pillars. Furthermore, quantification of the contact angle hysteresis (CAH) shows that, for the case of lower pillar spacing, CAH could increase up to 41%, whereas for the case of higher pillar spacing, this increment was up to 35%, both corresponding to the maximum eccentricity of 6 m. In general, the maximum obtainable hydrophobicity corresponds to micropillars with zero eccentricity. As the pillar relative spacing decreases, the effect of eccentricity on hydrophobicity becomes more pronounced. The dependence of the wettability conditions of the micropatterned surface on the pillar eccentricity is attributed to the contact line deformation resulting from the changed orientation of the pillars. This finding provides additional insights in design and fabrication of efficient micropatterned surfaces with controlled wetting properties.
Kashaninejad, N, Nguyen, NT & Chan, WK 2012, 'Eccentricity effects of microhole arrays on drag reduction efficiency of microchannels with a hydrophobic wall', Physics of Fluids, vol. 24, no. 11.View/Download from: Publisher's site
This paper experimentally investigates the effects of microhole eccentricity on the slip lengths of Stokes flow in microchannels with the bottom wall made of microhole arrays. The wettability of such microhole structures fabricated by the replica molding of polydimethylsiloxane is first analyzed measuring both static and dynamic contact angles. Subsequently, the drag reduction performance of the microchannels with such hydrophobic microhole surfaces is evaluated. The results indicate that the impact of microhole eccentricity on drag reduction performance correlates well with the contact angle hysteresis rather than with the static contact angle. Furthermore, microhole arrays with large normalized width and zero eccentricity show the minimum contact angle hysteresis of 18.7°. In these microchannels, the maximum percentage increase in the relative velocity is 39% corresponding to a slip length of 2.49 m. For the same normalized width, increasing the normalized eccentricity to 2.6 increases the contact angle hysteresis to 36.5° that eventually reduces the percentage increase in relative velocity and slip length down to 16% and 0.91 m, respectively. The obtained results are in qualitative agreement with the existing theoretical and numerical models. These findings provide additional insights in the design and fabrication of efficient micropatterned channels for reducing the flow resistanceleave open questions for theoreticians to further investigate in this field. © 2012 American Institute of Physics.
Sanaye, S, Dehghandokht, M & Fartaj, A 2011, 'Temperature control of a cabin in an automobile using thermal modeling and fuzzy controller', APPLIED ENERGY, 3rd International Conference on Applied Energy (ICAE), ELSEVIER SCI LTD, Perugia, ITALY, pp. 860-868.View/Download from: Publisher's site
Kashaninejad, N, Chan, WK & Nguyen, NT 2011, 'Fluid mechanics of flow through rectangular hydrophobic microchannels', ASME 2011 9th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM 2011, pp. 647-655.View/Download from: Publisher's site
In this study, the effect of two important parameters have been evaluated for pressure driven liquid flows in microchannel in laminar regime by analytical modeling, followed by experimental measurement. These parameters are wettability conditions of microchannel surfaces and aspect ratio of rectangular microchannels. For small values of aspect ratio, the channel was considered to have a rectangular cross-section, instead of being two parallel plates. Novel expressions for these kinds of channels were derived using eigenfunction expansion method. The obtained two-dimensional solutions based on dual finite series were then extended to the case of a constant slip velocity at the bottom wall. In addition, for large values of aspect ratio, a general equation was obtained which is capable of accounting for different values of slip lengths for both upper and lower channel walls. Firstly, it was found out that for low aspect ratio microchannels, the results obtained by analytical rectangular 2-D model agree well with the experimental measurements as compared to one dimensional solution. For high aspect ratio microchannels, both models predict the same trend. This finding indicates that using the conventional 1-D solution may not be accurate for the channels where the width is of the same order as the height. Secondly, experimental results showed that up to 2.5% and 16% drag reduction can be achieved for 1000 and 250 micron channel height, respectively. It can be concluded that increasing the surface wettability can reduce the pressure drop in laminar regime and the effect is more pronounced by decreasing the channel height. Copyright © 2011 by ASME.