Microfluidic Platforms For The Investigation Of Fuel Cell Catalysts And Electrodes

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Microfluidic Platforms for the Investigation of Fuel Cell Catalysts and Electrodes

Author : Fikile R. Brushett
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (776 download)

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Book Synopsis Microfluidic Platforms for the Investigation of Fuel Cell Catalysts and Electrodes by : Fikile R. Brushett

Download or read book Microfluidic Platforms for the Investigation of Fuel Cell Catalysts and Electrodes written by Fikile R. Brushett and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A clear need exists for novel approaches to producing and utilizing energy in more efficient ways, in light of society0́9s ever increasing demand as well as growing concerns with respect to climate change related to CO2 emissions. The development of low temperature fuel cell technologies will continue to play an important role in many alternative energy conversion strategies, especially for portable electronics and automotive applications. However, widespread commercialization of fuel cell technologies has yet to be achieved due to a combination of high costs, poor durability and, system performance limitations (Chapter 1). Developing a better understanding of the complex interplay of electrochemical, transport, and degradation processes that govern the performance and durability of novel fuel cell components, particularly catalysts and electrodes, within operating fuel cells is critical to designing robust, inexpensive configurations that are required for commercial introduction. Such detailed in-situ investigations of individual electrode processes are complicated by other factors such as water management, uneven performance across electrodes, and temperature gradients. Indeed, too many processes are interdependent on the same few variable parameters, necessitating the development of novel analytical platforms with more degrees of freedom. Previously, membraneless microfluidic fuel cells have been developed to address some of the aforementioned fuel cell challenges (Chapter 2). At the microscale, the laminar nature of fluid flow eliminates the need for a physical barrier, such as a stationary membrane, while still allowing ionic transport between electrodes. This enables the development of many unique and innovative fuel cell designs. In addition to addressing water management and fuel crossover issues, these laminar flow-based systems allow for the independent specification of individual stream compositions (e.g., pH). Furthermore, the use of a liquid electrolyte enables the simple in-situ analysis of individual electrode performance using an off-the-shelf reference electrode. These advantages can be leveraged to develop microfluidic fuel cells as versatile electro-analytical platforms for the characterization and optimization of catalysts and electrodes for both membrane- and membraneless fuel cells applications. To this end, a microfluidic hydrogen-oxygen (H2/O2) fuel cell has been developed which utilizes a flowing liquid electrolyte instead of a stationary polymeric membrane. For analytical investigations, the flowing stream (i) enables autonomous control over electrolyte parameters (i.e., pH, composition) and consequently the local electrode environments, as well as (ii) allows for the independent in-situ analyses of catalyst and/or electrode performance and degradation characteristics via an external reference electrode (e.g., Ag/AgCl). Thus, this microfluidic analytical platform enables a high number of experimental degrees of freedom, previously limited to a three-electrode electrochemical cell, to be employed in the construct of working fuel cell. Using this microfluidic H2/O2 fuel cell as a versatile analytical platform, the focus of this work is to provide critical insight into the following research areas: 0́Ø Identify the key processes that govern the electrode performance and durability in alkaline fuel cells as a function of preparation methods and operating parameters (Chapter 3). 0́Ø Determine the suitability of a novel Pt-free oxygen reduction reaction catalyst embedded in gas diffusion electrodes for acidic and alkaline fuel cell applications (Chapter 4). 0́Ø Establish electrode structure-activity relationships by aligning in-situ electrochemical analyses with ex-situ microtomographic (MicroCT) structural analyses (Chapter 5). 0́Ø Investigate the feasibility and utility of a microfluidic-based vapor feed direct methanol fuel cell (VF-DMFC) configuration as a power source for portable applications (Chapter 6). In all these areas, the information garnered from these in-situ analytical platforms will advance the development of more robust and cost-effective electrode configurations and thus more durable and commercially-viable fuel cell systems (both membrane-based and membraneless).

Microfluidic Platforms and Fundamental Electrocatalysis Studies for Fuel Cell Applications

Author : Jamie Lee Cohen
Publisher :
ISBN 13 :
Total Pages : 1178 pages
Book Rating : 4.E/5 ( download)

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Book Synopsis Microfluidic Platforms and Fundamental Electrocatalysis Studies for Fuel Cell Applications by : Jamie Lee Cohen

Download or read book Microfluidic Platforms and Fundamental Electrocatalysis Studies for Fuel Cell Applications written by Jamie Lee Cohen and published by . This book was released on 2007 with total page 1178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Microfluidic Microbial Fuel Cells for Microstructure Interrogations

Author : Erika Andrea Parra
Publisher :
ISBN 13 :
Total Pages : 286 pages
Book Rating : 4.:/5 (868 download)

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Book Synopsis Microfluidic Microbial Fuel Cells for Microstructure Interrogations by : Erika Andrea Parra

Download or read book Microfluidic Microbial Fuel Cells for Microstructure Interrogations written by Erika Andrea Parra and published by . This book was released on 2010 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: The breakdown of organic substances to retrieve energy is a naturally occurring process in nature. Catabolic microorganisms contain enzymes capable of accelerating the disintegration of simple sugars and alcohols to produce separated charge in the form of electrons and protons as byproducts that can be harvested extracellularly through an electrochemical cell to produce electrical energy directly. Bioelectrochemical energy is then an appealing green alternative to other power sources. However, a number of fundamental questions must be addressed if the technology is to become economically feasible. Power densities are low, hence the electron flow through the system: bacteria-electrode connectivity, the volumetric limit of catalyst loading, and the rate-limiting step in the system must be understood and optimized. This project investigated the miniaturization of microbial fuel cells to explore the scaling of the biocatalysis and generate a platform to study fundamental microstructure effects. Ultra-micro-electrodes for single cell studies were developed within a microfluidic configuration to quantify these issues and provide insight on the output capacity of microbial fuel cells as well as commercial feasibility as power sources for electronic devices. Several devices were investigated in this work. The first prototype consisted of a gold array anode on a silicon dioxide passivation layer that intended to imitate yet simplify the complexity of a 3D carbon structure on a 2D plane. Using Geobacter sulfurreducens, an organism believed to utilize direct electron transfer to electrodes, the 1 mm2 electrode demonstrated a maximum current density of 1.4 [mu]A and 120 nW of power after 10 days. In addition, the transient current-voltage responses were analyzed over the bacterial colonization period. The results indicated that over a 6-day period, the bacteria increased the capacitance of the cell 5-orders-of-magnitude and decreased the resistance by 3X over the bare electrode. Furthermore, over short experimental scales (hours), the RC constant was maintained but capacitance and resistance were inversely related. As the capacitance result coincides with expected biomass increase over the incubation period, it may be possible for an electrical spectroscopy (impedance) non-invasive technique to be developed to estimate biomass on the electrode. Similarly, the R and C relationship over short experimental scales could be explored further to provide insight on biolm morphology. Lastly, fluorescence and SEM microscopy were used to observe the biofilm development and demonstrated that, rather than growing at even density, the bacteria nucleated at points on the electrode, and dendritically divided, until joining to form the "dense" biofilm. In addition, viable microorganisms undergoing cell division were found dozens of microns from electrode surfaces without visible pili connections. To investigate single-cell catalysis or microstructure effects, a sub-micro-liter microfluidic single-channel MFC with an embedded reference electrode and solid-state nal electron acceptor was developed. The system allowed for parallel (16) working ultra-micro-electrodes and was microscopy compatible. With Geobacter sulfurreducens, the semiconducting ITO electrodes demonstrated forward bias behavior and suitability for anodic characterization. The first prototype demonstrated, with 179 cells on the electrode, a per cell contribution of 223 fA at +400 mV (vs. SHE). The second prototype with a 7 [mu]m diameter electrode produced a current density of 3.9 pA/[mu]m2 (3.9 A/m2) at +200 mV (vs. SHE) and a signal-to-noise ratio (SNR) of 4.9 when inoculated at a seeding density of 109 cells/mL. However, diluting the sample by 10x produced an SNR of 0.5, suggesting that obtaining single cell electron transfer rates to an electrode over short experimental time scales may not be possible with the system as tested. Nevertheless, the platform allows microstructure characterization and multiplexing within a single microfluidic chamber.

Microfluidic Fuel Cells and Batteries

Author : Erik Kjeang
Publisher : Springer
ISBN 13 : 3319063464
Total Pages : 81 pages
Book Rating : 4.3/5 (19 download)

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Book Synopsis Microfluidic Fuel Cells and Batteries by : Erik Kjeang

Download or read book Microfluidic Fuel Cells and Batteries written by Erik Kjeang and published by Springer. This book was released on 2014-06-14 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microfluidic fuel cells and batteries represent a special type of electrochemical power generators that can be miniaturized and integrated in a microfluidic chip. Summarizing the initial ten years of research and development in this emerging field, this SpringerBrief is the first book dedicated to microfluidic fuel cell and battery technology for electrochemical energy conversion and storage. Written at a critical juncture, where strategically applied research is urgently required to seize impending technology opportunities for commercial, analytical, and educational utility, the intention is for this book to be a ‘one-stop shop’ for current and prospective researchers in the general area of membraneless, microfluidic electrochemical energy conversion. As the overall goal of the book is to provide a comprehensive resource for both research and technology development, it features extensive descriptions of the underlying fundamental theory, fabrication methods, and cell design principles, as well as a thorough review of previous contributions in this field and a future outlook with recommendations for further work. It is hoped that the content will entice and enable new research groups and engineers to rapidly gain traction in their own laboratories towards the development of next generation microfluidic electrochemical cells.

High Performance Fuel-Breathing Microfluidic Fuel Cells

Author : Yifei Wang
Publisher :
ISBN 13 : 9781361041956
Total Pages : pages
Book Rating : 4.0/5 (419 download)

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Book Synopsis High Performance Fuel-Breathing Microfluidic Fuel Cells by : Yifei Wang

Download or read book High Performance Fuel-Breathing Microfluidic Fuel Cells written by Yifei Wang and published by . This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "High Performance Fuel-breathing Microfluidic Fuel Cells" by Yifei, Wang, 王夷飞, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of the thesis entitled "HIGH PERFORMANCE FUEL-BREATHING MICROFLUIDIC FUEL CELLS" Submitted by Yifei, Wang for the degree of Doctor of Philosophy at The University of Hong Kong in September 2016 Fuel cells are broadly regarded as one of the most promising power sources. A fuel cell is generally composed of a thin membrane electrolyte sandwiched by two porous electrodes, which has a similar structure with batteries. Fuel cells are very advantageous considering their high energy density, uninterrupted operation and environmental friendliness. To date, the application of this technology is vigorously promoted by the government and industry especially for large-power applications. As for applications with small rated power, the progress is, however, impeded by their high cost, leading to less competitiveness against the mature battery technology. To lower down the cost, microfluidic fuel cell (MFC), also known as the membraneless fuel cell or laminar flow fuel cell, has been proposed recently. A MFC generally utilizes two laminar flows in parallel as electrolyte instead of any solid membrane, therefore, lowering the fabrication cost. To prevent the flows from violent mixing, micro-channel, normally with characteristic length less than 1mm, is requisite. In this manner, the mixing process is dominated by slow diffusion, forming a flow interface in the middle of the channel as a virtual membrane. Despite of its cost advantage, there are still many unsolved problems in MFCs such as poor energy density, trade-off between cell performance and fuel utilization, complex fluidic management, etc. In this thesis, research works on MFC development have been done to improve their cell performance, energy efficiency, energy density, long-term stability, etc. In addition, a novel MFC stacking strategy has been proposed, which was proved to be competent for practical applications.  First, conventional liquid-feed MFCs with either co-flow or counter-flow configuration were studied. Their cell performance and fuel utilization were optimized, which were used as benchmarks in subsequent studies.  To solve the intractable restrictions in liquid-feed MFCs, vapor-feed MFCs were proposed which breathed fuel vapor from outside the cell instead of acquiring dissolved fuel from the inside electrolyte, therefore, -2 achieving both high power density (55.4mWcm ) and high energy efficiency (9.4%) at the same time.  To better understand the mechanism behind its performance, numerical (R) simulation on vapor-feed MFCs was also conducted using COMSOL 4.2.  To achieve practical power output, a circular stacking strategy was proposed, which was especially suitable for fuel-breathing MFCs. A six- cell stack was designed and tested, proving that such a stacking strategy was not only highly efficient but also potentially robust to external flow disturbance.  The same stacking strategy was also applied to H -fueled MFCs to further improve the power output. By utilizing Al-H O reaction for H generation, 2 2 the proposed Al-feed MFC stack achieved a peak power output of 530mW. Meanwhile, difficulties in hydrogen storage and waste electrolyte management were eliminated.  In MFCs with enlarged electrode areas, cathode flooding was inevitably aggravated and cell performance dropped significantly. By cracking the cathode catalyst layer, this problem was greatly alleviated, leading to a m

Encyclopedia of Microfluidics and Nanofluidics

Author : Dongqing Li
Publisher : Springer Science & Business Media
ISBN 13 : 0387324682
Total Pages : 2242 pages
Book Rating : 4.3/5 (873 download)

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Book Synopsis Encyclopedia of Microfluidics and Nanofluidics by : Dongqing Li

Download or read book Encyclopedia of Microfluidics and Nanofluidics written by Dongqing Li and published by Springer Science & Business Media. This book was released on 2008-08-06 with total page 2242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering all aspects of transport phenomena on the nano- and micro-scale, this encyclopedia features over 750 entries in three alphabetically-arranged volumes including the most up-to-date research, insights, and applied techniques across all areas. Coverage includes electrical double-layers, optofluidics, DNC lab-on-a-chip, nanosensors, and more.

Advances in Microfluidics

Author : Xiao-Ying Yu
Publisher : BoD – Books on Demand
ISBN 13 : 9535127853
Total Pages : 424 pages
Book Rating : 4.5/5 (351 download)

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Book Synopsis Advances in Microfluidics by : Xiao-Ying Yu

Download or read book Advances in Microfluidics written by Xiao-Ying Yu and published by BoD – Books on Demand. This book was released on 2016-11-23 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing innovations and applications make microfluidics a versatile choice for researchers in many disciplines. This book consists of multiple review chapters that aim to cover recent advances and new applications of microfluidics in biology, electronics, energy, and materials sciences. It provides comprehensive views of various aspects of microfluidics ranging from fundamentals of fabrication, flow control, and droplet manipulation to the most recent exploration in emerging areas such as material synthesis, imaging and novel spectroscopy, and marriage with electronics. The chapters have many illustrations showcasing exciting results. This book should be useful for those who are eager to learn more about microfluidics as well as researchers who want to pick up new concepts and developments in this fast-growing field.

Fabrication of Microfluidic Devices with Application to Membraneless Fuel Cells

Author : Jon McKechnie
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (858 download)

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Book Synopsis Fabrication of Microfluidic Devices with Application to Membraneless Fuel Cells by : Jon McKechnie

Download or read book Fabrication of Microfluidic Devices with Application to Membraneless Fuel Cells written by Jon McKechnie and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is part of an ongoing collaborative research project focused on the development of microstructured enzymatic fuel cells. Both enzymatic fuel cells and co-laminar fuel cells are, more generally, varieties of microfluidic membraneless fuel cells. A primary goal of this particular work is the establishment of microfabrication capabilities to develop these technologies. Rapid prototyping soft lithography capabilities are established in-house and protocols specific to the lab equipment are developed. These prototyping methods are then adapted for the fabrication of microfluidic membraneless fuel cells. Fabrication techniques using polymeric stencils and photoresist-based channel structures are developed to enable electrode patterning and current collection in the enzymatic and co-laminar fuel cells of interest. A variety of electrode patterning methods are developed. Gold electrode patterning by etching and lift-off techniques are investigated for the patterning of base electrode layers. An in-situ gold electrode patterning methodology is designed and tested, eliminating the need for precision alignment during device assembly. Carbon electrode patterning methods are developed for use in a vanadium-based colaminar fuel cell. Thin-film carbon electrodes are fabricated using a mixture of carbon microparticles and a polymeric binder. Alternatively, graphite rods are investigated for use as electrodes due to their high conductivity and chemical stability. The integration of channel structure and electrode fabrication methods is investigated to establish compatibilities and facilitate the assembly of functional devices. In addition to the development of these methods, the application of co-laminar streaming to microfabrication is explored through the development of a dynamic microfluidic photomasking device.

Microfluidic Platform for Studying the Electrochemical Reduction of Carbon Dioxide

Author : Devin T. Whipple
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (774 download)

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Book Synopsis Microfluidic Platform for Studying the Electrochemical Reduction of Carbon Dioxide by : Devin T. Whipple

Download or read book Microfluidic Platform for Studying the Electrochemical Reduction of Carbon Dioxide written by Devin T. Whipple and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Diminishing supplies of conventional energy sources and growing concern over greenhouse gas emissions present significant challenges to supplying the world0́9s rapidly increasing demand for energy. The electrochemical reduction of carbon dioxide has the potential to address many of these issues by providing a means of storing electricity in chemical form. Storing electrical energy as chemicals is beneficial for leveling the output of clean, but intermittent renewable energy sources such as wind and solar. Electrical energy stored as chemicals can also be used as carbon neutral fuels for portable applications allowing petroleum derived fuels in the transportation sector to be replaced by more environmentally friendly energy sources. However, to be a viable technology, the electrochemical reduction of carbon dioxide needs to have both high current densities and energetic efficiencies (Chapter 1). Although many researchers have studied the electrochemical reduction of CO2 including parameters such as catalysts, electrolytes and temperature, further investigation is needed to improve the understanding of this process and optimize the performance (Chapter 2). This dissertation reports the development and validation of a microfluidic reactor for the electrochemical reduction of CO2 (Chapter 3). The design uses a flowing liquid electrolyte instead of the typical polymer electrolyte membrane. In addition to other benefits, this flowing electrolyte gives the reactor great flexibility, allowing independent analysis of each electrode and the testing of a wide variety of conditions. In this work, the microfluidic reactor has been used in the following areas: 0́Ø Comparison of different metal catalysts for the reduction of CO2 to formic acid and carbon monoxide (Chapter 4). 0́Ø Investigation of the effects of the electrolyte pH on the reduction of CO2 to formic acid and carbon monoxide (Chapter 5). 0́Ø Study of amine based electrolytes for lowering the overpotentials for CO2 reduction and suppressing undesirable hydrogen evolution (Chapter 6). 0́Ø Investigation of the effects of reaction temperature on the Faradaic efficiency and current density for CO2 reduction on several catalysts (Chapter 7). These studies demonstrate the utility of this flexible reactor design and provide increased understanding of the electrochemical reduction of CO2 and the critical parameters for optimization of this process.

Fabrication of Microfluidic Devices with Application to Membraneless Fuel Cells

Author : Jon McKechnie
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (858 download)

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Book Synopsis Fabrication of Microfluidic Devices with Application to Membraneless Fuel Cells by : Jon McKechnie

Download or read book Fabrication of Microfluidic Devices with Application to Membraneless Fuel Cells written by Jon McKechnie and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is part of an ongoing collaborative research project focused on the development of microstructured enzymatic fuel cells. Both enzymatic fuel cells and co-laminar fuel cells are, more generally, varieties of microfluidic membraneless fuel cells. A primary goal of this particular work is the establishment of microfabrication capabilities to develop these technologies. Rapid prototyping soft lithography capabilities are established in-house and protocols specific to the lab equipment are developed. These prototyping methods are then adapted for the fabrication of microfluidic membraneless fuel cells. Fabrication techniques using polymeric stencils and photoresist-based channel structures are developed to enable electrode patterning and current collection in the enzymatic and co-laminar fuel cells of interest. A variety of electrode patterning methods are developed. Gold electrode patterning by etching and lift-off techniques are investigated for the patterning of base electrode layers. An in-situ gold electrode patterning methodology is designed and tested, eliminating the need for precision alignment during device assembly. Carbon electrode patterning methods are developed for use in a vanadium-based colaminar fuel cell. Thin-film carbon electrodes are fabricated using a mixture of carbon microparticles and a polymeric binder. Alternatively, graphite rods are investigated for use as electrodes due to their high conductivity and chemical stability. The integration of channel structure and electrode fabrication methods is investigated to establish compatibilities and facilitate the assembly of functional devices. In addition to the development of these methods, the application of co-laminar streaming to microfabrication is explored through the development of a dynamic microfluidic photomasking device.

Fabrication of Microfluidic Devices with Application to Membraneless Fuel Cells

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (68 download)

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Book Synopsis Fabrication of Microfluidic Devices with Application to Membraneless Fuel Cells by :

Download or read book Fabrication of Microfluidic Devices with Application to Membraneless Fuel Cells written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is part of an ongoing collaborative research project focused on the development of microstructured enzymatic fuel cells. Both enzymatic fuel cells and co-laminar fuel cells are, more generally, varieties of microfluidic membraneless fuel cells. A primary goal of this particular work is the establishment of microfabrication capabilities to develop these technologies. Rapid prototyping soft lithography capabilities are established in-house and protocols specific to the lab equipment are developed. These prototyping methods are then adapted for the fabrication of microfluidic membraneless fuel cells. Fabrication techniques using polymeric stencils and photoresist-based channel structures are developed to enable electrode patterning and current collection in the enzymatic and co-laminar fuel cells of interest. A variety of electrode patterning methods are developed. Gold electrode patterning by etching and lift-off techniques are investigated for the patterning of base electrode layers. An in-situ gold electrode patterning methodology is designed and tested, eliminating the need for precision alignment during device assembly. Carbon electrode patterning methods are developed for use in a vanadium-based colaminar fuel cell. Thin-film carbon electrodes are fabricated using a mixture of carbon microparticles and a polymeric binder. Alternatively, graphite rods are investigated for use as electrodes due to their high conductivity and chemical stability. The integration of channel structure and electrode fabrication methods is investigated to establish compatibilities and facilitate the assembly of functional devices. In addition to the development of these methods, the application of co-laminar streaming to microfabrication is explored through the development of a dynamic microfluidic photomasking device.

Microfluidic Fuel Cells

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (654 download)

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Book Synopsis Microfluidic Fuel Cells by :

Download or read book Microfluidic Fuel Cells written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Microfluidic fuel cell architectures are presented in this thesis. This work represents the mechanical and microfluidic portion of a microfluidic biofuel cell project. While the microfluidic fuel cells developed here are targeted to eventual integration with biocatalysts, the contributions of this thesis have more general applicability. The cell architectures are developed and evaluated based on conventional non-biological electrocatalysts. The fuel cells employ co-laminar flow of fuel and oxidant streams that do not require a membrane for physical separation, and comprise carbon or gold electrodes compatible with most enzyme immobilization schemes developed to date. The demonstrated microfluidic fuel cell architectures include the following: a single cell with planar gold electrodes and a grooved channel architecture that accommodates gaseous product evolution while preventing crossover effects; a single cell with planar carbon electrodes based on graphite rods; a three-dimensional hexagonal array cell based on multiple graphite rod electrodes with unique scale-up opportunities; a single cell with porous carbon electrodes that provides enhanced power output mainly attributed to the increased active area; a single cell with flow-through porous carbon electrodes that provides improved performance and overall energy conversion efficiency; and a single cell with flow-through porous gold electrodes with similar capabilities and reduced ohmic resistance. As compared to previous results, the microfluidic fuel cells developed in this work show improved fuel cell performance (both in terms of power density and efficiency). In addition, this dissertation includes the development of an integrated electrochemical velocimetry approach for microfluidic devices, and a computational modeling study of strategic enzyme patterning for microfluidic biofuel cells with consecutive reactions.

Biofuel's Engineering Process Technology

Author : Marco Aurelio Dos Santos Bernardes
Publisher : BoD – Books on Demand
ISBN 13 : 9533074809
Total Pages : 746 pages
Book Rating : 4.5/5 (33 download)

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Book Synopsis Biofuel's Engineering Process Technology by : Marco Aurelio Dos Santos Bernardes

Download or read book Biofuel's Engineering Process Technology written by Marco Aurelio Dos Santos Bernardes and published by BoD – Books on Demand. This book was released on 2011-08-01 with total page 746 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book aspires to be a comprehensive summary of current biofuels issues and thereby contribute to the understanding of this important topic. Readers will find themes including biofuels development efforts, their implications for the food industry, current and future biofuels crops, the successful Brazilian ethanol program, insights of the first, second, third and fourth biofuel generations, advanced biofuel production techniques, related waste treatment, emissions and environmental impacts, water consumption, produced allergens and toxins. Additionally, the biofuel policy discussion is expected to be continuing in the foreseeable future and the reading of the biofuels features dealt with in this book, are recommended for anyone interested in understanding this diverse and developing theme.

Materials and Methods for Microfluidic Fuel Cells

Author : Ben Nearingburg
Publisher :
ISBN 13 :
Total Pages : 207 pages
Book Rating : 4.:/5 (92 download)

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Book Synopsis Materials and Methods for Microfluidic Fuel Cells by : Ben Nearingburg

Download or read book Materials and Methods for Microfluidic Fuel Cells written by Ben Nearingburg and published by . This book was released on 2014 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microfluidic fuel cell (MFC) devices are a promising route towards on-chip power generation for microfluidic and lab-on-a-chip systems. Current MFCs leverage fabrication techniques and materials that have been inherited from micromachining technology and macro-scale fuel cell devices. Both, these methods and materials can be costly and difficult to integrate into larger microfluidic networks or lab-on-a-chip devices. In order to fully explore the utility of MFCs, device should be composed of common microfluidic materials (i.e. formed from the same materials as the rest of the device) and amendable to fabrication alongside other components of microfluidic devices (i.e. not require specialized equipment/techniques for patterning). This thesis set out to improve the applicability of MFC devices by enhancing fabrication methods and describing new functional materials to better align MFCs with microfluidic device architectures. To achieve this goal, I focused my efforts on improving individual sub-components of the MFC device architecture to yield more effective devices. Throughout this thesis, emphasis was placed upon leveraging techniques amenable to low-cost bench-top processing (i.e. those that do not require expensive capital equipment) to broaden the applicability of MFC devices. My work was applied to three components of planar MFC devices (where a device consists of a single sided microchannel and a flat capping layer). First, proton exchange membranes capable of in situ patterning were developed and characterized. Second, oxygen transport through air breathing polymer layers was assessed through finite element modelling to better understand factors governing air breathing MFC devices. Finally, a new technique, multi-layer in situ laminar flow lithography, was introduced and characterized. This technique was shown to allow for patterning of multi-layer metal films to yield independent catalytic electrodes. Functional alkaline direct methanol fuel cell devices were then fabricated and characterized using the technique. The utility and applicability of each of these techniques to both MFCs and the wider field of microfluidics was assessed and possible applications discussed.

Micro Fuel Cells

Author : Tim Zhao
Publisher : Academic Press
ISBN 13 : 0080878873
Total Pages : 312 pages
Book Rating : 4.0/5 (88 download)

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Book Synopsis Micro Fuel Cells by : Tim Zhao

Download or read book Micro Fuel Cells written by Tim Zhao and published by Academic Press. This book was released on 2009-07-07 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Today's consumers of portable electronics consumers are demanding devices not only deliver more power but also work healthy for the environment. This fact alone has lead major corporations like Intel, BIC, Duracell and Microsoft to believe that Microfuel Cells could be the next-generation power source for electronic products. Compact and readable, Microfuels Principles and Applications, offers engineers and product designers a reference unsurpassed by any other in the market. The book starts with a clear and rigorous exposition of the fundamentals engineering principles governing energy conversion for small electronic devices, followed by self-contained chapters concerning applications. The authors provide original points of view on all types of commercially available micro fuel cells types, including micro proton exchange membrane fuel cells, micro direct methanol fuel cells, micro solid oxide fuel cells and micro bio-fuel cells. The book also contains a detailed introduction to the fabrication of the components and the assembly of the system, making it a valuable reference both in terms of its application to product design and understanding micro engineering principles. An overview of the micro fuel cell systems and applications A detailed introduction to the fabrication of the components and the assembly of the system Original points of view on prospects of micro fuel cells

Microfluidic Fuel Cells as Analytical Platforms

Author : Fikile R. Brushett
Publisher :
ISBN 13 :
Total Pages : 148 pages
Book Rating : 4.:/5 (612 download)

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Book Synopsis Microfluidic Fuel Cells as Analytical Platforms by : Fikile R. Brushett

Download or read book Microfluidic Fuel Cells as Analytical Platforms written by Fikile R. Brushett and published by . This book was released on 2009 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Membraneless Microfluidic Fuel Cells

Author : Kamil S. Salloum
Publisher :
ISBN 13 :
Total Pages : 111 pages
Book Rating : 4.:/5 (81 download)

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Book Synopsis Membraneless Microfluidic Fuel Cells by : Kamil S. Salloum

Download or read book Membraneless Microfluidic Fuel Cells written by Kamil S. Salloum and published by . This book was released on 2010 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: Portable devices rely on battery systems that contribute largely to the overall device form factor and delay portability due to recharging. Membraneless microfluidic fuel cells are considered as the next generation of portable power sources for their compatibility with higher energy density reactants. Microfluidic fuel cells are potentially cost effective and robust because they use low Reynolds number flow to maintain fuel and oxidant separation instead of ion exchange membranes. However, membraneless fuel cells suffer from poor efficiency due to poor mass transport and Ohmic losses. Current microfluidic fuel cell designs suffer from reactant cross-diffusion and thick boundary layers at the electrode surfaces, which result in a compromise between the cell's power output and fuel utilization. This dissertation presents novel flow field architectures aimed at alleviating the mass transport limitations. The first architecture provides a reactant interface where the reactant diffusive concentration gradients are aligned with the bulk flow, mitigating reactant mixing through diffusion and thus crossover. This cell also uses porous electro-catalysts to improve electrode mass transport which results in higher extraction of reactant energy. The second architecture uses porous electrodes and an inert conductive electrolyte stream between the reactants to enhance the interfacial electrical conductivity and maintain complete reactant separation. This design is stacked hydrodynamically and electrically, analogous to membrane based systems, providing increased reactant utilization and power. These fuel cell architectures decouple the fuel cell's power output from its fuel utilization. The fuel cells are tested over a wide range of conditions including variation of the loads, reactant concentrations, background electrolytes, flow rates, and fuel cell geometries. These experiments show that increasing the fuel cell power output is accomplished by increasing reactant flow rates, electrolyte conductivity, and ionic exchange areas, and by decreasing the spacing between the electrodes. The experimental and theoretical observations presented in this dissertation will aid in the future design and commercialization of a new portable power source, which has the desired attributes of high power output per weight and volume and instant rechargeability.