Microfluidic paper based membraneless biofuel cell to harvest energy from various beverages

The present work establishes the cost-effective and miniature microfluidic self-pumping paper based enzymatic biofuel cell (P-EBFC). The developed Y-shaped P-EBFC consists of buckeye composite multiwall carbon nanotube (MWCNT) buckypaper (BP) based bioanode and bio-cathode that were immobilized with electro-biocatalytic enzymes glucose oxidase (GOx) and laccase, respectively. The electrocatalytic activity of enzymes on electrode surface is confirmed using cyclic voltammetry (CV) technique. Such immobilized bio-anode and bio-cathode show exquisite electrocatalytic activity towards glucose and O2, respectively. Most appealingly, P-EBFC can directly harvest energy from widely available beverages containing glucose such as Mountain Dew, Pepsi, 7up and fresh watermelon juice. This could provide potential application of P-EBFC as a portable power device

Platinum utilization in proton exchange membrane fuel cell and direct methanol fuel cell

Proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC) are increasingly used as substitutes to conventional energy systems. Their compact design, high energy density and efficient energy-conversion offer several advantages over existing energy systems with potential for use in a variety of applications. However, performance, robustness and cost are the key challenges to overcome before fuel cells can be commercialized. Even though the use of platinum (Pt) and platinum group metal (PGM) alloy catalysts provide higher performance and durability, they are at the same time the largest cost components which need to be addressed. This paper reviews different approaches adopted to enhance Pt utilization such as reducing Pt loading, decreasing Pt particle size, developing Pt free metallic alloy catalyst, improving Pt dispersion, developing membrane electrode assembly (MEA) fabrication methods, increasing mass-transport at the electrode surface and modifying the catalyst support materials. Finally, the performance optimization efforts for Pt utilization are summarized with insights into probable directions of future research in this area

OPENTELEMETRY EXTENSION FOR SUPPORTING CALL GRAPHS

A call graph is an important feature in the application performance monitoring (APM) domain that helps users diagnose issues within their production applications. However, call graphs are not supported by OpenTelemetry because OpenTelemetry agents lack a mechanism for the collection of data. Techniques described herein provide for extending OpenTelemetry agents to automatically collect data required for call graph creation

Graphite electrodes as bioanodes for enzymatic glucose biofuel cell

This study investigates the performance of pencil graphite (PG) electrodes to identify the grade of pencil most suitable as bioanode for enzymatic glucose biofuel cell. Pencils of H, 3H, 5H and B grades are selected for this study. The surfaces of different grade PGs are modified with carboxylic acid functionalized multi walled carbon nanotubes (COOH-MW­CNT/PG), followed by immobilization with glucose oxidase (GOx) to fabricate the respect­tive bioanodes (GOx/COOH-MWCNT/PG). Morphological and electrochemical characteri­zations are carried out using scanning electron microscopy, electrochemical impedance spectroscopy, cyclic voltammetry and energy dispersive X-ray spectroscopy. All tested PG electrodes exhibited positive results with variable response characteristics towards glucose oxidation reaction. B-grade PG bioanode is found to have the highest coverage of the deposited nanobiocomposite with the fastest electron transfer rate. The half-cell electrode assembly with this grade of PG recorded the highest current density of 4.25 mA cm-2 at physiological glucose conditions (5 mM glucose, pH 7.0). Enzymatic glucose biofuel cell assembled with B-grade PG bioanode and platinum cathode generated an open circuit potential of 149 mV and maximum power density of 0.789 µW cm−2 from 5 mM glucose at ambient conditions (25 ± 3◦C). The results obtained for B-grade PG bioanode are comparable to those of conventional carbon and glassy carbon electrodes, thus demonstrating its applicability to enzymatic glucose biofuel cells.</p

IoT enabled carbon cloth-based 3D printed hydrogen fuel cell integrated with supercapacitor for low-power microelectronic devices

Abstract A Hydrogen fuel cell (HFC) broad range associated with Internet of Things (IoT) technologies that require slightly less and constant electricity made possible by remote climate monitoring connections. Novelty demonstrates a miniature HFC based on carbon cloth electrodes and sealing elements manufactured via 3D printing. Cobalt (II) Oxide (Co3O4)—reduced Graphene Oxide (rGO) and Platinum (Pt) based nanoparticles are coated over carbon cloth to increase the catalytic activity at the anode and cathode. Hydrogen is produced by using an aluminium foil (Al) that is stored in between the filter paper and through capillary action the sodium hydroxide pellets (NaOH) are applied and reacted with Al foil to produce hydrogen. The single HFC device working surface area of 1 × 1 cm2 effectively generates an open circuit voltage (OCV) of 1.3 V, a current density of 1.602 mA/cm2, and a peak power density of 761 mW/cm2. The fuel cell stability performance is monitored for up to 10 h. The power obtained from the HFC is stored in a supercapacitor and used to supply energy to the IoT component. The module includes a built-in sensor that monitors the temperature, pressure, and humidity. The measured data is then transmitted to a smartphone via Bluetooth

Enzymatic fuel cells in a microfluidic environment: Status and opportunities. A mini review

International audienceMiniaturized Enzymatic Fuel Cells (EFCs) have attracted great attention due to the possibility of integrating them with various low-powered microelectronic devices. In a flow-through system, harnessing the co-laminar property of microfluidics, membraneless microfluidic EFCs (M-MEFC) can be designed, enhancing the ease of use of bio-devices and offering opportunities for new concepts. This brief review encompasses the development, current challenges and future pathways in the field of M-MEFCs, focusing in particular on some fabrication aspects and related device performance