bluuebunny/crossref_metadata_2025_split huggingface dataset:
Membrane-Less Microbial Fuel Cell Powering a Smart Phone: A Self-Stratifying Urine Column
Authors: Walter Xavier Alexis , Gajda Iwona , Forbes Samuel , Stinchcombe Andrew , Greenman John , Ieropoulos Ioannis 
Published: February 2020

The microbial fuel cell (MFC) is a technology in which microorganisms employ an electrode (anode) as a solid electron acceptor for anaerobic respiration. This result in direct transformation of chemical energy into electrical energy, which in turn means that organic wastewater can be used as fuel. Amongst the various organic wastes that are employed as fuel for MFCs, urine is of interest since it represents 75% of the nitrogen present in domestic wastewaters and yet only 1% of the total volume. However, here is a persistent problem for the scaling up of MFCs. The smaller the surface of electrode to volume ratio of an MFC is, the higher its power density is. Hence, to reach usable power levels, a plurality of units needs to be assembled in stack, which implies configuring both the hydraulic circuitry and the serial/parallel electrical connection patterns. Because of this plurality, the units need to have a simple design for the whole system to be cost-effective. The goal of this work is to address how to build these multiple MFCs in stack.
We report a novel membrane-less stack design using manifold ceramic plates semi-submerged with anodes and cathodes sharing urine solution. The top half of each plate were semi-submerged were covered in cathodes while the anodes, on the lower half of each plate, were fully submerged. The MFCs in each box were connected in parallel and multiple modules were configured in series and placed. This allowed self-stratification of the collective environment (urine column) under the natural activity of the microbial consortia thriving in the system. For size comparisons, the module footprints were enlarged from 900 mL to 5000 mL and, importantly, this scaling-up did not negatively affect power density (» 19 W/m^3), a factor that has proven an obstacle in previous studies. However, we should note that this observation is limited for the dimensions we tested. This was achieved by maintaining a plurality of microenvironments within the collective system and resulted in a simple, robust system fuelled by urine. The developed system was then used to treat urine of single individual (» 2.5L per 24h), in order to serve as the energy source charging mobile phones. Six boxes, each comprising 20 MFCs connected in parallel, were hydraulically cascaded and connected in series. Best performances were obtained in pulse-feed batch mode. At equilibrium, the stack of six boxes was feed with 600 mL every 6h at a flow rate of 2 L/min and was producing between 110 and 125 mW. Under these conditions, a smart phone (Samsung Galaxy S, battery of 1600 mAh) was fully charged in 68 h and 80 h, when turned off or on respectively. It has to be noted that these performances were stable for a period of 8 months. We concluded that our scaling-up approach within the tested range was successful to convert chemical energy in urine to electricity and this was demonstrated by charging cell phones.
(Invited) Ionic Liquids for Rechargeable Metal Batteries
Authors: Kar Mega , Howlett Patrick C , Forsyth Maria , MacFarlane Douglas R 
Published: February 2020

The emergence of global warming driven by greenhouse gases has put tremendous emphasis on the need to develop improved large scale energy storage systems including low-cost, and high energy density batteries such as rechargeable metal batteries. Batteries in which metals such as lithium (Li), magnesium (Mg), sodium (Na) and zinc (Zn) act as the electroactive species offer great potential in these applications. Room temperature ionic liquids (RTILs) that are, generally, non-volatile, non-flammable and thermally stable have recently been shown to enhance the electrochemical characteristics and long-term cycling of some of these metals[
1
]. For example, Figure 1 below compares the charging behaviour of a Li|LiCoO2 cell in conventional organic electrolyte (solid bold line) to that of RTIL (dashed line)[
2
]. The high rate charging behaviour is substantially improved in the latter electrolyte due to the high solubility of Li ions in the RTIL. The thermal stability of RTILs is also becoming very significant in offering improved safety with these large-scale batteries.
Recent work has demonstrated the importance of functional groups in the RTIL cations and anions [
3
] and the role of additives[
4
] in influencing speciation and electrochemical behaviour. These functionalised ILs are providing a pathway towards cheaper, rechargeable batteries such as those based on zinc[
5
] and magnesium[
6
].
This talk will discuss recent work from our group, and others, in these areas.

Figure 1: 1 C to 5 C charging profiles of organic liquid electrolyte [1M LiPF6, EC:DMC = 50:50 vol.%] (Solid bold line) and 3.2 mol.kg-1 LiFSI in C3mpyrFSI (Dashed line). (Reproduced from ref [
2
]).
[1] a) M. Kar, T. J. Simons, M. Forsyth, D. MacFarlane, Phys. Chem. Chem. Phys.
2014, 16, 18658-18674; b) D. R. MacFarlane, M. Forsyth, P. Howlett, M. Kar, S. Passerini, J. Pringle, H. Ohno, M. Watanabe, F. Yan, W. Zheng, S. Zhang, J. Zhang, Nature Review Materials
2016 - in press.
[2] H. Yoon, P. C. Howlett, A. S. Best, M. Forsyth, D. R. MacFarlane, J. Electrochem. Soc.
2013, 160, A1629-A1637.
[3] M. Kar, B. Winther-Jensen, M. Forsyth, D. R. MacFarlane, Phys. Chem. Chem. Phys.
2013, 15, 7191-7197.
[4] T. J. Simons, A. A. J. Torriero, P. C. Howlett, D. R. MacFarlane, M. Forsyth, Electrochem. Commun.
2012, 18, 119-122.
[5] a) M. Kar, T. J. Simons, B. Winther-Jensen, M. Forsyth, M. Armand, D. MacFarlane, Electrochim. Acta
2014; b) T. J. Simons, M. Salsamendi, P. C. Howlett, M. Forsyth, D. R. Macfarlane, C. Pozo-Gonzalo, ChemElectroChem
2015.
[6] M. Kar, Ma, Z., Chen, K, Azofra, L. M, Forysth, M, MacFarlane, D.R., Chem Comm - submmitted
2015.

Figure 1
(Keynote) Wearable Electrochemical Sensors
Authors: Wang Joseph 
Published: February 2020

The presentation will discuss the status and potential of textile- and tattoo-based flexible screen-printed electrochemical sensors. The portable nature and low power demands of electrochemical system satisfy many of the requirements for on-body sensing. Miniaturized electrochemical systems offer tremendous potential for obtaining the desired analytical information in a faster, simpler (“user-friendly”), and cheaper manner compared to traditional laboratory-based assays. Thick-film (screen-printing) microfabrication has been widely used for mass production of highly reproducible electrochemical sensors (e.g., glucose strips for diabetics). This process has recently been applied for printing flexible electrochemical sensors but not in connection to common textiles and garments. The integration of printable sensors directly onto fabrics and garments, such as those described in this presentation, would provide the wearers with the ability to continuously assess their health and condition. Since the performance of textile- and tattoo-based electrochemical sensors is directly related to the printing quality, it is imperative that the printing protocol and ink formulation be tailored for the specific substrate material.

The presentation will review recent advances in developing flexible printable textile- and tattoo-based electrochemical sensors. We will describe the preparation and characterization of various textile-based and skin-worn electrochemical sensors, will illustrate their favorable electrochemical behavior and examine the influence of the clothing stretching and folding upon their sensing performance. Such mechanical stress studies indicate that textile-based printed electrochemical sensors survive large deformations. Technical challenges and prospects for using textile- and tattoo-based electrochemical sensors for monitoring the wearer’s health, fitness, or surrounding environment will be discussed, along with several demonstrations and prospects for future healthcare and sport applications.
A Versatile Bioanode with Improved Current Density and the Coulombic Efficiency through a Cascade Reaction
Authors: Zafar Muhammad Nadeem , Aslam Iqra , Murtaza Shahzad , Gorton Lo 
Published: February 2020

To improve communications between enzymes and electrodes, many different methods were developed including the use of diffusional electron mediators, the “wiring” of enzymes through immobilization in redox polymers, the functionalization of enzymes with electron relays, and the use of nanomaterials. Recently a new promising strategy was reported, in which the glycoprotein glucose oxidase (GOx) was directly electrically contacted with the electrodes after removal of the glycosylating layer. Although a lot of advances in the electrical communication between enzymes and electrodes has made it possible to fabricate new biosensors and biofuel cells, the technologies still face challenging issues, such as development of long-term stable miniaturized implantable amperometric biosensors and biofuel cells.
Our approach to the development of a glucose biofuel cell anode is based on the combination of different redox enzymes with complementary oxidation positions thus forming a reaction cascade to oxidize the substrate at more than one position. Improvements in current density and coulombic efficiency of a glucose oxidizing electrode were realized by a combination of pyranose dehydrogenase from Agaricus meleagris (AmPDH) with either glucose dehydrogenase from Glomerella cingulata (GcGDH) or cellobiose dehydrogenase from Myriococcum thermophilum (MtCDH). The mixed enzyme electrode oxidizes glucose in several combinations at the C-1, C-2 and C-3 positions of the pyranose ring. This concerted action of enzymes increases (i) the coulombic efficiency by extracting more than 2 e- per substrate molecule and (ii) the current density of the electrode when the mass-transfer of substrates becomes rate limiting. The electrodes were investigated with flow injection analysis (FIA) using different substrates under physiological conditions (pH 7.4). These investigations showed that the product of one enzyme can be used as substrate for the other enzyme and maximally 6 e- can be gained from the oxidation of one glucose molecule using mixed enzyme electrodes like AmPDHb/GcGDH/Os-polymer 2 or the AmPDHa/MtCDH/Os-polymer 1. We propose a bioanode for use in biofuel cells with an increased current density and coulombic efficiency obtained by a cascade reaction catalyzed by redox enzymes with a different site-specificity for glucose.
Smart Patch Systems: Iontophoretic Microheater Assemblies for Controlled Transdermal Delivery
Authors: McConville Aaron , Davis James 
Published: February 2020

The majority of currently approved transdermal drug delivery systems utilise low doses of low molecular weight lipophilic drugs, falling within the category of first generation approaches. Systems incorporating improvements such as chemical enhancers, heat, iontophoresis and non-cavitational ultrasound to reversibly disrupt the structure of the stratum corneum, fall under second generation approaches. Although heat is a somewhat uncommon and perhaps understudied enhancement technique, there is considerable evidence to suggest that it can significantly increase epidermal penetration. Given the tolerable nature of these temperatures, there is a clear opportunity for heat assisted absorption to be incorporated into future transdermal drug delivery systems. The use of heat has been shown to increase the rate of transdermal drug delivery in a number of applications, such as administration of fentanyl and lidocaine. The aim of the present project has been to investigate the development of a hybrid smart patch system, which involves the integration of transdermal heat transfer with iontophoresis. This would enable enhanced drug delivery to be achieved in a controlled manner without significant disruption to the skin’s structure.
Iontophoresis provides a mechanism through which delivery rate may be controlled to a high degree of specificity. It is therefore possible to regulate or inhibit delivery rate over a period of time, due to the direct relationship between the applied current and transdermal flux. Rate control may be the responsibility of the patient, or more commonly, controlled by incorporation of a microprocessor, enabling complex and bespoke delivery profiles to be enacted. The addition of the transdermal heater, in this instance, brings a new dimension to the delivery process, but there remains a considerable challenge to the design and implementation of the proposed smart patch.
The basic approach is outlined in Figure 1. In order to address the issue of controlled release and subsequent flux, the design incorporates a temperature sensitive hydrogel as a drug entrapment matrix or reservoir. Hydrogels have traditionally been employed as a barrier mechanism or encapsulation medium in a number of drug delivery studies, where their manipulation and/or degradation may be controlled by environmental influences, hydrolysis and enzyme interaction. In this prototype, thermal control (typically 45oC) facilities the release of drug from the gel, and its subsequent transfer across the stratum corneum is induced through the combination of heat and iontophoresis.
The design of the microheater / iontophoretic electrode assembly is described and its operation characterised. The drug delivery profiles from prototype smart patches employing a range of model drugs are critically assessed. The extent to which precise control and augmentation of both the release and transdermal delivery rate, for a range of drug species and therapeutic agents has been assessed.

Figure 1
(Invited) Elucidation of Lithiation Process As a Function of Structural and Chemical Transformations in Li2MnO3
Authors: Persson Kristin A , Shin Yongwoo 
Published: February 2020

The layered Li2MnO3 is a key component in the Li/Mn-rich cathode materials, and provides a representative end-member for the spectrum of compositions reported in the literature. While exhibiting excellent initial capacity, the Li excess materials suffer from voltage fade, high impedance, and poor rate capability, particularly in the Mn-rich, high Li excess concentration regime. In this talk we present insights about the Li electrochemical reactivity of Li2MnO3, from first-principles calculations. In particular, we elucidate the bulk lithiation/delithiation mechanism in pristine bulk LixMnO3 for 1< x < 2, involving coherent Li migration from the two Li-containing layers. Surprisingly, and contrary to expectations from available experimental results, we find that the pristine material exhibits excellent Li mobility enabling a Li rate capability on par with the well-known layered LiCoO2. For lower Li contents (x < 1), we have previously shown that Li2MnO3 becomes increasingly unstable towards manganese migration into the Li layer as well as oxygen loss at the surface. We systematically investigate the influence of these factors on the lithiation/delithiation process, which provides a hypothesis for the experimentally observed slow, and increasingly poor, electrochemical response of this material.
Real-Time Dynamic Simulation of Electrochemical Battery Models for Grid Applications
Authors: Lee Seong Beom , Pathak Manan , Gao Wenzhong , Viswanathan Vilayanur , Subramanian Venkat R. 
Published: February 2020

Lithium-ion batteries are important energy storage systems implemented in a microgrid and they are the most expensive single component, accounting for about 60% of overall capital expenditure1. As of today, however, the microgrid significantly underutilizes the battery’s performance, which causes high cost and low energy efficiency in the grid operation. For example, the microgrid involves large battery modules. In order to perform the most accurate simulation and control of these systems the model must include multiple cells in parallel series. For large modules charge balancing becomes problematic2. Not all the cells will be at the same state of charge and health. However, current technology considers battery packs as just one big battery/a black box having the same state of charge and health.
This talk will present progress in real-time simulation of physics based models for batteries in the microgrid framework including batteries, power electronics, energy generators and controls.

Acknowledgements

The authors acknowledge financial support from the University of Washington’s Clean Energy Institute and Washington Research Foundation.

References

1. Ivanova, N. Lithium-ion costs to fall by up to 50% within five years. http://analysis.energystorageupdate.com/lithium-ion-costs-fall-50-within-five-years.
2. Moore, S. W.; Schneider, P. J. A review of cell equalization methods for lithium ion and lithium polymer battery systems; SAE Technical Paper: 2001.
Smoothed Boundary Method Simulations of Electrochemical Impedance Spectroscopy for Energy Materials with Complex Microstructures
Authors: Yu Hui-Chia , Choe Min-Ju , Chiang Yet-Ming , Amatucci Glenn G , Thornton Katsuyo 
Published: February 2020

Electrochemical impedance spectroscopy (EIS) is commonly utilized to measure ionic and electronic conductivities in energy materials (e.g., battery and solid oxide fuel cell electrodes), which are often represented as equivalent circuits that contain capacitors and resistors. Although effective capacitance and resistance can be calculated with the simplified representation as circuits, such representation cannot incorporate microstructural characteristics (e.g., porosity, tortuosity, grain boundary density, etc.) that strongly influence the performance of these energy materials. For example, the grain boundary network can enhance or hinder the overall transport of ions and electrons, which in turn influence polarization. Such a microstructural effect cannot be captured with the simplified representation as circuits. As such, a comprehensive model of EIS should take into account the microstructural characteristics that play a crucial role in determining material properties and device performance.
In this work, we develop an innovative approach based on the smoothed boundary method, which allows us to simulate EIS behavior of materials with complex microstructures. Using a continuous domain parameter to define the geometry of a porous electrode, different physical mechanisms, such as surface transport along irregular particle surfaces, electrochemical reaction at the particle surfaces, and diffusion through the tortuous complex bulk of the electrode, are coupled and taken into account in the simulation of the ion concentration responding to oscillating loadings. In addition, using multiple domain parameters, each of which defines a primary cathode particle, transport through complex grain boundary networks in secondary particles is simulated and accounted for in the simulation of the EIS response. From the simulation results, the effects of microstructures and the impact of interface/boundary transport on EIS behavior are elucidated.
This work is supported by the NorthEast Center for Chemical Energy Storage (NECCES), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award Numbers DE-SC0012583.
Development of Peptide Functionalized Smart Bandages for Real-Time Wound Diagnostics
Authors: McLister Anna , Cundell Jill , Finlay Dewar , Davis James 
Published: February 2020

The treatment of chronic wounds, particularly those associated with diabetic complications, is a perennial problem for modern healthcare services, affecting an ever-increasing portion of society.This is particularly worrisome given that the diabetic population and associated costs are set to at least double in size in the next 25 years. In the US alone, approximately 6.5 million people suffer from slow healing wounds, with healthcare costs in the region of $25 billion annually. A critical factor that needs to be considered when dealing with chronic wounds is infection. This can have a huge impact on healing time and could inevitably lead to further discomfort of the patient and complications that could ultimately be life threatening. Most chronic wounds (>74%) are treated within the community and as such there can be a delay in the patient seeking medical attention resulting in a deterioration of the wound condition. It is estimated that 12% of individuals with a chronic foot ulcer, will require amputation due to infection.
A new approach to the design of disposable pH sensors that can be directly integrated within conventional wound dressings and which can communicate to an app on a smart phone (Figure 1) is described. The system is based on an aminoacid / peptide functionalized electrode interface through which the pH can be rapidly determine through either potentiometric or voltammetric means. It has been shown that wound pH can be a versatile marker of wound condition and can be used to track the stage of healing. Importantly, sustained changes in pH from a given regime could provide an early warning signal for the early onset of infection. A range of bioactive groups have been assessed in terms of their ability to facilitate the long term/periodic monitoring of pH with a matrix which can express significant amounts of exudate that would otherwise irreversibly contaminate conventional electrode substrates.
This presentation details characterization of the fabrication processes, the electrode response and the clinical utility of the measurement. The integration of the sensing substrate within the dressing and its communication with the smart phone/tablet via an Arduino system is described and critically assessed. Ultimately, the aim would be for the development of a prototype that would be able to alert the patient to the onset of infection.

Figure 1
The Effect of Alloying of Transition Metals (M = Fe, Co and Ni) to Palladium Catalyst on Durability of Electrocatalytic Activity of Oxygen Reduction Reaction in Alkaline Media
Authors: Gunji Takao , Wakabayashi Ryo , Abruña Héctor D. , DiSalvo Francis , Matsumoto Futoshi 
Published: February 2020

Polymer electrolyte membrane (PEMs) fuel cells have attracted a great deal of attention as next-generation electrical portable device due to the high energy efficiencies and carbon-free emission. However, the cost of electrocatalyts in PEMs is very high because platinum (Pt) is used as electrocatalyst for both the oxidation of hydrogen in the anode and oxygen reduction reaction (ORR) in the cathode. Palladium (Pd) is an attractive candidate as an alternative electrocatalyst towards the ORR in alkaline media because Pd is more abundant, much less expensive than Pt, and has a higher activity towards ORR than pure Pt in alkaline media [1]. Stable and long-term electrocatalytic performance towards the ORR was achieved by Pd-shell Pd3
M-core (M = Fe, Co, Ni and Cu) structures on carbon supports. Herein, we report on the synthesis of Pd-based bimetallic compounds using 3d transition metals, such as Fe, Co, and Ni, as secondary materials and demonstrate enhanced electrocatalytic activity towards the ORR in alkaline media as well as improved durability. The catalytic activity of these nanoparticles has been compared to that of pure Pd nanoparticles. We have also dealloyed the catalysts using electrochemical treatment by potential cycles in alkaline media and examined their activities towards the ORR.
The various bimetallic Pd-M (M = Fe, Co and Ni) nanoparticles (NPs) were prepared by an impregnation method followed by an annealing treatment. In order to enhance the electrocatalytic activity towards the ORR, bimetallic Pd-M nanoparticles were electrochemically deallyoed. Dealloyed Pd-M NPs exhibit a core-shell structure, Pd3
M-Core and Pd-shell, and showed enhanced catalytic activity towards the ORR as well as better durability than pure Pd.
[1] Sun, W.; Hsu, A.; Chen, R.; J. Power Sources, 2011, 196, 4491.