Academic literature on the topic 'Nano-flow pumping system'
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Journal articles on the topic "Nano-flow pumping system"
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Yan, Di, Qian Tang, Ahmed Kovacevic, Yuanxun Zhang, Wei Liu, Pinghua Liang, and Huijun Zhang. "Designing nano-aluminum laden fuel pump for aviation applications." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 234, no. 6 (June 25, 2020): 634–43. http://dx.doi.org/10.1177/0954408920935315.
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In view of the fact that traditional liquid propellants cannot meet the design requirements of large-thrust flight vehicle, it has become a new trend to add nano-metal powder to liquid propellants to greatly increase density and specific impulse. In order to achieve the variable flow-rate and variable-proportion transportation of aviation fuel with nano-aluminum, a new type of solid-liquid mixing pumping system is designed, including powder conveying device, stirring device, pump and corresponding drive and transmission system. For the purpose of avoiding the frictional contact between the rotors, which will bring potential hazard to nano-aluminum powder, a non-contact twin-screw pump with synchronous gears is designed. Among them, based on the considerations of flow pulsation, volumetric efficiency and manufacturing difficulty, cycloid profile is adopted for screw rotors. After completing the functional design, geometric parameter design, structural design, 3D modeling, prototype manufacturing and preliminary performance estimation of the mixing pumping system, the performance of the screw feeder, agitator, screw pump was tested through experiments to meet the expected design requirements. The designed agitator can achieve sufficient mixing at 500 rpm in less than 10 s. Even though 50-micron clearances are designed with a relatively small rotor diameter, the volumetric efficiency of screw pump can reach above 50% when the discharge pressure is below 450 kPa and the flow rate is set as 10 L/min, the power of the screw pump is less than 700 W. This design facilitates the rapid real-time preparation of metallized propellants and provides a reference for further improving the design and control methods of nanoparticle two-phase flow pumping.
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Lim, Jong Yeon, Wan Sup Cheung, Yong Moon Choi, Dae Jin Seong, Yong Hyeon Shin, and Kwang Hwa Chung. "Low Vacuum Generation and Control on BIEN Technology: Mass Flow and Dry Pumping Characteristics." Key Engineering Materials 277-279 (January 2005): 1000–1005. http://dx.doi.org/10.4028/www.scientific.net/kem.277-279.1000.
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Since a clean environment and finite mass flow control on the molecular level are continuously required in current R&D fields and actual process lines, technologies on vacuum generation and control have been playing a significant role in merging a variety of technologies like Bio, Information, Environment, Energy, Space and Nano. Currently, the drive towards dry vacuum pumping has broadly occurred across a spectrum of vacuum applications, from semiconductor manufacture to industrial processing, due to its most visible advantages: it is contamination free. The integrated characteristics evaluation system for dry vacuum pumps has been established in KRISS in collaboration with several branch dry pump suppliers in Korea. The evaluation system exploits a constant volume flow meter to measure mass flow rates real-timely in standard level, and facilitates the evaluation of spatially averaged sound power levels using a semi-anechoic chamber. New and overhauled roots, claw, classical screw, and scroll type pumps supplied from the manufacturers have been evaluated using the evaluation system in terms of ultimate pressure, pumping speed, vibration, and sound power. We selected the mass flow measuring method with a constant chamber volume of 875 L because of its direct monitoring capability which does not allow blind mass flow rate measurements, and proved that the method allows us to measure five decades of mass flow rates from 1×10-2 to 1×103 mbar-l/s with a measurement uncertainty of ±3%, which is within the internationally accepted standards limit. In this work, we demonstrate how the integrated pump characteristics evaluation and mass flow control method have been significant in the low vacuum range of 10-4 to 103 mbar.
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Yaroshchuk, A., E. E. Licón, E. K. Zholkovskiy, M. P. Bondarenko, and T. Heldal. "Asymmetric electroosmotic pumping across porous media sandwiched with perforated ion-exchange membranes." Faraday Discussions 199 (2017): 175–93. http://dx.doi.org/10.1039/c6fd00248j.
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To have non-zero net flow in AC electroosmotic pumps, the electroosmosis (EO) has to be non-linear and asymmetric. This can be achieved due to ionic concentration polarization. This is known to occur close to micro-/nano-interfaces provided that the sizes of the nanopores are not too large compared to the Debye screening length. However, operation of the corresponding EO pumps can be quite sensitive to the solution concentration and, thus, unstable in practical applications. Concentration polarization of ion-exchange membranes is much more robust. However, the hydraulic permeability of the membrane is very low, which makes EO flows through them extremely small. This communication shows theoretically how this problem can be resolved via making scarce microscopic perforations in an ion-exchange membrane and putting it in series with an EO-active nano-porous medium. The problem of coupled flow, concentration and electrostatic-potential distributions is solved numerically by using finite-element methods. This analysis reveals that even quite scarce perforations of micron-scale diameters are sufficient to observe practically-interesting EO flows in the system. If the average distance between the perforations is smaller than the thickness of the EO-active layer, there is an effective homogenization of the electrolyte concentration and hydrostatic pressure in the lateral direction at some distance from the interface. The simulations show this distance to be somewhat lower than the half-distance between the perforations. On the other hand, when the surface fraction of perforations is sufficiently small (below a fraction of a percent) this “homogeneous” concentration is considerably reduced (or increased, depending on the current direction), which makes the EO strongly non-linear and asymmetric. This analysis provides initial guidance for the design of high-productivity and inexpensive AC electroosmotic pumps.
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Marrec, Pierre, Gérald Grégori, Andrea M. Doglioli, Mathilde Dugenne, Alice Della Penna, Nagib Bhairy, Thierry Cariou, et al. "Coupling physics and biogeochemistry thanks to high-resolution observations of the phytoplankton community structure in the northwestern Mediterranean Sea." Biogeosciences 15, no. 5 (March 15, 2018): 1579–606. http://dx.doi.org/10.5194/bg-15-1579-2018.
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Abstract. Fine-scale physical structures and ocean dynamics strongly influence and regulate biogeochemical and ecological processes. These processes are particularly challenging to describe and understand because of their ephemeral nature. The OSCAHR (Observing Submesoscale Coupling At High Resolution) campaign was conducted in fall 2015 in which a fine-scale structure (1–10 km∕1–10 days) in the northwestern Mediterranean Ligurian subbasin was pre-identified using both satellite and numerical modeling data. Along the ship track, various variables were measured at the surface (temperature, salinity, chlorophyll a and nutrient concentrations) with ADCP current velocity. We also deployed a new model of the CytoSense automated flow cytometer (AFCM) optimized for small and dim cells, for near real-time characterization of the surface phytoplankton community structure of surface waters with a spatial resolution of a few kilometers and an hourly temporal resolution. For the first time with this optimized version of the AFCM, we were able to fully resolve Prochlorococcus picocyanobacteria in addition to the easily distinguishable Synechococcus. The vertical physical dynamics and biogeochemical properties of the studied area were investigated by continuous high-resolution CTD profiles thanks to a moving vessel profiler (MVP) during the vessel underway associated with a high-resolution pumping system deployed during fixed stations allowing sampling of the water column at a fine resolution (below 1 m). The observed fine-scale feature presented a cyclonic structure with a relatively cold core surrounded by warmer waters. Surface waters were totally depleted in nitrate and phosphate. In addition to the doming of the isopycnals by the cyclonic circulation, an intense wind event induced Ekman pumping. The upwelled subsurface cold nutrient-rich water fertilized surface waters and was marked by an increase in Chl a concentration. Prochlorococcus and pico- and nano-eukaryotes were more abundant in cold core waters, while Synechococcus dominated in warm boundary waters. Nanoeukaryotes were the main contributors (>50 %) in terms of pigment content (red fluorescence) and biomass. Biological observations based on the mean cell's red fluorescence recorded by AFCM combined with physical properties of surface waters suggest a distinct origin for two warm boundary waters. Finally, the application of a matrix growth population model based on high-frequency AFCM measurements in warm boundary surface waters provides estimates of in situ growth rate and apparent net primary production for Prochlorococcus (μ=0.21 d−1, NPP =0.11 mgCm-3d-1) and Synechococcus (μ=0.72 d−1, NPP =2.68 mgCm-3d-1), which corroborate their opposite surface distribution pattern. The innovative adaptive strategy applied during OSCAHR with a combination of several multidisciplinary and complementary approaches involving high-resolution in situ observations and sampling, remote-sensing and model simulations provided a deeper understanding of the marine biogeochemical dynamics through the first trophic levels.
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Ortiz-Rivera, Isamar, Henry Shum, Arjun Agrawal, Ayusman Sen, and Anna C. Balazs. "Convective flow reversal in self-powered enzyme micropumps." Proceedings of the National Academy of Sciences 113, no. 10 (February 22, 2016): 2585–90. http://dx.doi.org/10.1073/pnas.1517908113.
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Surface-bound enzymes can act as pumps that drive large-scale fluid flows in the presence of their substrates or promoters. Thus, enzymatic catalysis can be harnessed for “on demand” pumping in nano- and microfluidic devices powered by an intrinsic energy source. The mechanisms controlling the pumping have not, however, been completely elucidated. Herein, we combine theory and experiments to demonstrate a previously unreported spatiotemporal variation in pumping behavior in urease-based pumps and uncover the mechanisms behind these dynamics. We developed a theoretical model for the transduction of chemical energy into mechanical fluid flow in these systems, capturing buoyancy effects due to the solution containing nonuniform concentrations of substrate and product. We find that the qualitative features of the flow depend on the ratios of diffusivities δ=DP/DS and expansion coefficients β=βP/βS of the reaction substrate (S) and product (P). If δ>1 and δ>β (or if δ<1 and δ<β), an unexpected phenomenon arises: the flow direction reverses with time and distance from the pump. Our experimental results are in qualitative agreement with the model and show that both the speed and direction of fluid pumping (i) depend on the enzyme activity and coverage, (ii) vary with the distance from the pump, and (iii) evolve with time. These findings permit the rational design of enzymatic pumps that accurately control the direction and speed of fluid flow without external power sources, enabling effective, self-powered fluidic devices.
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Ziółkowski, Paweł, and Janusz Badur. "A theoretical, numerical and experimental verification of the Reynolds thermal transpiration law." International Journal of Numerical Methods for Heat & Fluid Flow 28, no. 1 (January 2, 2018): 64–80. http://dx.doi.org/10.1108/hff-10-2016-0412.
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Purpose The purpose of this paper is the theoretical presentation of tensorial formulation with surface mobility forces and numerical verification of Reynolds thermal transpiration law in a contemporary experiment with nanoflow. Design/methodology/approach The velocity profiles in a single microchannel are calculated by solving the momentum equations and using thermal transpiration force as the boundary conditions. The mass flow rate and pressure of unstationary thermal transpiration modeling of the benchmark experiment has been achieved by the implementation of the thermal transpiration mobility force closure for the thermal momentum accommodation coefficient. Findings An original and easy-to-implement method has been developed to numerically prove that at the final equilibrium, i.e. zero-flow state, there is a connection between the Poiseuille flow in the center of channel and counter thermal transpiration flow on the surface. The numerical implementation of the Reynolds model of thermal transpiration has been performed, and its usefulness for the description of the benchmark experiment has been verified. Research limitations/implications The simplified procedure requires the measurement or assumption of the helium-glass slip length. Practical implications The procedure can be very useful in the design of micro-electro-mechanical systems and nano-electro-mechanical systems, especially for accommodation pumping. Originality/value The paper discussed possible constitutive equations in the transpiration shell-like layer. The new approach can be helpful for modeling phenomena occurring at a fluid–solid phase interface at the micro- and nanoscales.
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Machado, Mary C., Daniel Chang, Thomas J. Webster, and Keiko M. Tarquinio. "Assessment of Nanomodified Endotracheal Tubes in a Bench Top Airway Model." MRS Proceedings 1209 (2009). http://dx.doi.org/10.1557/proc-1209-yy08-06.
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AbstractVentilator associated pneumonia (VAP) is a serious and costly clinical problem. Specifically, receiving mechanical ventilation over 24 hours increases the risk of VAP and is associated with high morbidity, mortality and medical costs. This complication is especially hard to diagnose in children because of non-specific clinical signs and lack of established diagnostic methods. Cost effective endotracheal tubes (ETTs) that are resistant to bacterial infection would be essential tools for the prevention of VAP. In addition to their bacterial resistance, ETT with magnetic nanoparticles could aid in the diagnosis of VAP allowing physicians to locate infections with greater accuracy. The objective of this study was twofold, first to develop strategies to decrease bacterial adhesion on nano-rough ETT and secondly to develop better methods to assessin vitrobacterial adhesion or biofilm formation on ETT. In preliminary tests, nanomodified polyvinyl chloride (PVC) ETTs has been shown to be effective at reducing bacterial colonization. This study also sought to evaluate the bacterial resistance of these ETTs more effectively by creating a bench top airway model, which can create a similar environment to the flow system that ETTs are exposed toin vivo. The airway model designed to test ETTs has two Plexiglas chambers representing the oropharynx and the lungs, a tube representing the trachea and finally an intricate pumping system to the oropharynx with bacteria flow and to the lung with simulated compliance and resistance. ETTs were connected to a ventilator and passing the oropharynx into the trachea and observed under the mechanical ventilation and continuous bacterial flow system. In addition, the study examined dual gas flow conditions and their effect on bacterial growth of ETT. In no less than three separate trials in the airway chamber, each ETT will be tested for its effectiveness at the reduction of bacterial growth within the airway by sampling from both lung and oropharynx chambers during continuous operation. Special attention will be given to the long-term effects on the ETT by including a study that lasts longer than ten days. Both the bacterial proliferation in the two chambers and on the ETT itself will be carefully analyzed. This specialized testing should yield valuable information on the efficacy of nanomodified ETT in airway conditions and will provide further evidence to determine if nanomodified ETTs are a valid solution to VAP.
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Karami, Sajedeh, Mohammad Mahdi Doroodmand, Mahnaz Taherianfar, Amir Mutabi-Alavi, and Nahid Nagshgar. "Mechanism behind the neuronal ephaptic coupling during synchronizing by specific brain-triggered wave as neuronal motor toolkit." Scientific Reports 11, no. 1 (February 11, 2021). http://dx.doi.org/10.1038/s41598-021-82118-2.
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AbstractProbable mechanism behind the neuronal ephaptic coupling is investigated based on the introduction of “Brain”-triggered potential excitation signal smartly with a specific very low frequency (VLF) waves as a neuronal motor toolkit. Detection of this electric motor toolkit is attributed to in-vitro precise analyses of a neural network of snail, along to the disconnected snail’s neuronal network as a control. This is achieved via rapid (real-time) electrical signals acquisition by blind patch-clamp method during micro-electrode implanting in the neurons at the gigaseal conditions by the surgery operations. This process is based on its waveform (potential excitation signal) detection by mathematical curve fitting process. The characterized waveform of this electrical signal is “Saw Tooth” that is smartly stimulated, alternatively, by the brain during triggering the action potential’s (AP’s) hyperpolarization zone at a certain time interval at the several µs levels. Triggering the neuron cells results in (1) observing a positive shift (10.0%, depending on the intensity of the triggering wave), and (2) major promotion in the electrical current from sub nano (n) to micro (µ) amper (nA, µA) levels. Direct tracing the time domain (i.e., electrical signal vs. time) and estimation of the frequency domain (diagram of electrical response vs. the applied electrical frequencies) by the “Discrete Fast Fourier Transform” algorithm approve the presence of bilateral and reversible electrical currents between axon and dendrite. This mechanism therefore opens a novel view about the neuronal motor toolkit mechanism, versus the general knowledge about the unilateral electrical current flow from axon to dendrite operations in as neural network. The reliability of this mechanism is evaluated via (1) sequential modulation and demodulation of the snail’s neuron network by a simulation electrical functions and sequentially evaluation of the neuronal current sensitivity between pA and nA (during the promotion of the signal-to-noise ratio, via averaging of 30 ± 1 (n = 15) and recycling the electrical cycles before any neuronal response); and (2) operation of the process on the differentiated stem cells. The interstice behavior is attributed to the effective role of Ca2+ channels (besides Na+ and K+ ionic pumping), during hyper/hypo calcium processes, evidenced by inductively coupled plasma as the selected analytical method. This phenomenon is also modeled during proposing quadrupole well potential levels in the neuron systems. This mechanism therefore points to the microprocessor behavior of neuron networks. Stimulation of the neuronal system based on this mechanism, not only controls the sensitivity of neuron electrical stimulation, but also would open a light window for more efficient operating the neuronal connectivity during providing interruptions by phenomena such as neurolysis as well as an efficient treatment of neuron-based disorders.
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"Novel Designs of Photovoltaic Thermal (PV/T) Systems." International Journal of Recent Technology and Engineering 8, no. 4 (November 30, 2019): 6223–29. http://dx.doi.org/10.35940/ijrte.d5144.118419.
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Advanced concepts of hybrid photovoltaic thermal (PV/T) collectors are proposed to improve electrical efficiency and utilize the waste heat as thermal energy. The use of air, water, and combinations of the two are considered traditional techniques. The complexity is raised when using advanced stateof-the-art systems to improve the overall efficiency of PV/T such as employing nanofluids, nano-Phase Change Material (PCM), heat pump and jet impingement. This paper presents a review of novel designs which are proposed in the literature to enhance the performance of PV/T collectors and from it the evaluation criteria is derived. The comparison between different designs could be based on having same pumping power, size, or designs; depending on the element intended for the comparison. The designs also vary according to the bias assigned; whether to improve electrical performance more, or thermal performance. The common aspects observed in the literature are investigations of mass flow rate, impact of solar irradiance, and design parameters such as pipe material, configuration and diameters
Dissertations / Theses on the topic "Nano-flow pumping system"
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Sharma, Sonika. "Hand-portable Capillary Liquid Chromatography Instrumentation." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/6164.
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This dissertation focuses on the development of hand-portable capillary liquid chromatography (LC) instrumentation. In this work, battery-operable nano-flow pumping systems (isocratic and gradient) were developed and integrated with portable UV-absorption detectors for capillary LC. The systems were reduced in size to acceptable weights and power usage for field operation. A major advantage of the pumps is that they do not employ a splitter, since they were specifically designed for capillary column use, thereby greatly reducing solvent consumption and waste generation. UV-absorption detectors were specifically designed and optimized for on-column detection to minimize extra-column band broadening. Initially, an isocratic nano-flow pumping system with a stop-flow injector was integrated with an on-column UV-absorption detector (254 nm). The pumping system gave excellent flow rate accuracy (<99.94%) and low percent injection carry-over (RSD 0.31%) suitable for quantitative analysis. Using sodium anthraquinone-2-sulfonate, the detector gave an LOD (S/N = 3) of 0.13 µM, which was 12 times lower than a commercial UV-absorption detector. Reversed-phase separations of a homologous series of alkyl benzenes was demonstrated. Further miniaturization of UV-absorption detection was accomplished using a 260 nm deep UV LED. The detector was small in size and weighed only 85 g (without electronics). No optical reference was included due to the low drift in the signal. Two ball lenses, one of which was integrated with the LED, were used to increase light throughput through the capillary column. Stray light was minimized by the use of a band-pass filter and an adjustable slit. Signals down to the ppb level (nM) were easily detected with a short-term noise level of 4.4 µAU, confirming a low limit of detection and low noise. The detection limit for adenosine-5'-monophosphate was 230 times lower than any previously reported values. Isocratic separations of phenolic compounds were performed using a poly(ethylene glycol) diacrylate monolithic capillary column. Finally, a novel nano-flow gradient generator integrated with a stop-flow injector was developed. Gradient performance was found to be excellent for gradient step accuracy (RSD < 1.2%, n = 4) and linear gradient reproducibility (RSD < 1.42%, n = 4). Separations of five phenols were demonstrated using the nano-flow gradient system. Efforts to develop a 405 nm laser diode-based UV-absorption detector for hemoglobin analysis were described.
Conference papers on the topic "Nano-flow pumping system"
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Guinn, John E., and Debjyoti Banerjee. "Experimental Study of Nanofluids for Droplet Cooling Applications Using Temperature Microsensors." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-14101.
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The use of nano-fluids in droplet cooling (boiling) was explored parametrically in this experimental study. The experimental parameters are: nanofluid composition, superheat, liquid subcooling, and spray parameters (nozzle diameter, injection distance, size of droplets, injection pressure, mass flow rate, etc.). Two test fluids were used in the experiments: de-ionized (DI) water and nanofluid. The nano-fluid consists of silica nano-particles with a nominal diameter of 10nm dissolved in water at 2% concentration by weight. An experimental apparatus was fabricated to measure the surface temperature fluctuations during spray cooling of a heated surface. An array of microthermocouples (Thin Film Thermocouples or "TFT") was micro-fabricated on a heated surface to measure the surface temperature fluctuations during spray cooling. The TFT are capable of measuring temperature fluctuations up to a speed of 100 MHz. In the experiments, the exit of the single droplet spray was set a distance of 10 mm away from the surface and was aligned with the location of the TFT array. The spray was produced by pumping test fluid using a syringe pump into a traversing spray head. Silicon wafers with surface micromachined TFT array were clamped on the top of the heater apparatus for measuring temperature changes on the surface of the heater. Wire bead K-Type thermocouples were embedded in the heater apparatus and were used to measure heat flux. The transient temperature data from the TFT were recorded by a data acquisition system connected to a computer. The nano-fluid spray was found to cause fouling of the heater surface due to precipitation of the constituent nano-particles during boiling. This caused the overall heat flux to decrease drastically when compared to spray cooling using water. The nano-fluid spray was found to enhance heat flux by 300% compared to the base heat flux without the spray.
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Jarrett, Hunter, Micah Wade, Joseph Kraai, Gregory L. Rorrer, Alan X. Wang, and Hua Tan. "Evaporation-Based Microfluidic Pump Using Super-Hydrophilic Diatom Biosilica Thin Films." In ASME 2019 Heat Transfer Summer Conference collocated with the ASME 2019 13th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/ht2019-3502.
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Abstract Diatoms are a group of single-celled photosynthetic algae that use biochemical pathways to bio-mineralize and self-assemble three-dimensional photonic crystals with unique photonic and micro- & nano-fluidic properties. In recent years, diatom biosilica has been used in surface-enhanced Raman scattering (SERS) based optofluidic sensors for detection of a variety of chemical and biological molecules. In this paper, we present a study to develop a microfluidic pumping system using super-hydrophilic diatom thin films. The desire to develop such a system stems from the requirement to create a low-cost, self-powered microfluidic pumping system that can sustain a continuous flow over an extended period of time. The diatom biosilica acts not only as the driving force behind the flow, but also serves as ultra-sensitive SERS substrates that allows for trace detection of various molecules. Liquid is drawn from a reservoir to the tip of a 150μm inner diameter capillary tube positioned directly over the diatom film. A thin and long horizontal reservoir is used to prevent flooding on the diatom film when the liquid is initially drawn to the diatom film through a capillary tube from the reservoir. The connection of the meniscus from the capillary to the film was maintained from a horizontal reservoir for a recorded time of 20 hours and 32 minutes before the partially filled reservoir emptied. Flow rates of 0.38, 0.22 and 0.16μL/min were achieved for square biosilica thin films of 49mm2, 25mm2, and 9mm2 at a temperature of 63°F and 45% relative humidity respectively. A temperature-controlled system was introduced for the 49mm2 substrate and flow rates of 0.60, 0.82, 0.93, and 1.15μL/min were observed at 72, 77, 86, and 95°F at 21% relative humidity respectively. More testing and analysis will be performed to test the operation limits of the proposed self-powered microfluidic system.