Dynamic Pluronic F127 Crosslinking Enhancement of Biopolymeric Nanocomposites for Piezo-Triboelectric Single-Hybrid Nanogenerators and Self-Powered Sensors (Small 21/2023)

Biomechanical and nanomechanical energy harvesting systems have gained a wealth of interest, resulting in a plethora of research into the development of biopolymeric-based devices as sustainable alternatives. Piezoelectric, triboelectric, and hybrid nanogenerator devices for electrical applications are engineered and fabricated using innovative, sustainable, facile-approach flexible composite films with high performance based on bacterial cellulose and BaTiO₃, intrinsically and structurally enhanced by Pluronic F127, a micellar cross-linker. The voltage and current outputs of the modified versions with multiwalled carbon nanotube as a conductivity enhancer and post-poling effect are 38 V and 2.8 µA cm⁻², respectively. The multiconnective devices’ power density can approach 10 µW cm⁻². The rectified output power is capable of charging capacitors, driving light-emitting diode lights, powering a digital watch and interfacing with a commercial microcontroller board to operate as a piezoresistive force sensor switch as a proof of concept. Magnetoelectric studies show that the composites have the potential to be incorporated into magnetoelectric systems. The biopolymeric composites prove to be desirable candidates for multifunctional energy harvesters and electronic devices.     

Flexible ZnO-cellulose nanocomposite for multisource energy conversion

Materials with the ability to harness multiple sources of energy from the ambient environment could lead to new types of energy-harvesting systems. It is demonstrated that nanocomposite films consisting of zinc oxide nanostructures embedded in a common paper matrix can be directly used as energy-conversion devices to transform mechanical and thermal energies to electric power. These mechanically robust and flexible devices can be fabricated over large areas and are capable of producing an output voltage and power up to 80 mV and 50 nW cm(-2) , respectively. Furthermore, it is shown that by integrating a certain number of devices (in series and parallel) the output voltage and the concomitant output power can be significantly increased. Also, the output voltage and power can be enhanced by scaling the size of the device. This multisource energy-harvesting system based on ZnO nanostructures embedded in a flexible paper matrix provides a simplified and cost-effective platform for capturing trace amounts of energy for practical applications.     

Advancements in dry powder delivery to the lung

The dry powder inhaler (DPI) has become widely known as a very attractive platform for drug delivery. Many patients have traditionally used DPIs to treat asthma and chronic obstructive pulmonary disease. Recently, the development of new DPIs for delivering therapeutic proteins such as insulin has been accelerated by patient demands, and innovative research. The current market for DPIs has over 20 devices presently in use, and many devices under development for delivering a variety of therapeutic agents. DPIs are recognized as suitable alternatives to pressurized metered dose inhalers for some patients, but the performance of DPI devices may vary according to a given patient's physiological condition. This variation can be associated with the necessary powder dispersion mechanism of each device. As such, much interest has focused on the development of efficient powder dispersion mechanisms, as this effectively minimizes the influence of interpatient variability. This article reviews DPI devices currently available, advantages of newly developed devices, outlines some requirements for future device design.     

Integrated solar capacitors for energy conversion and storage

Solar energy is one of the most popular clean energy sources and is a promising alternative to fulfill the increasing energy demands of modern society.Solar cells have long been under intensive research attention for harvesting energy from sunlight with a high power-conversion efficiency and low cost.However,the power outputs of photovoltaic devices suffer from fluctuations due to the intermittent instinct of the solar radiation.Integrating solar cells and energystorage devices as self-powering systems may solve this problem through the simultaneous storage of the electricity and manipulation of the energy output.This review summarizes the research progress in the integration of new-generation solar cells with supercapacitors,with emphasis on the structures,materials,performance,and new design features.The current challenges and future prospects are discussed with the aim of expanding research and development in this field.     

Advancements in Dry Powder Delivery to the Lung

The dry powder inhaler (DPI) has become widely known as a very attractive platform for drug delivery. Many patients have traditionally used DPIs to treat asthma and chronic obstructive pulmonary disease. Recently, the development of new DPIs for delivering therapeutic proteins such as insulin has been accelerated by patient demands, and innovative research. The current market for DPIs has over 20 devices presently in use, and many devices under development for delivering a variety of therapeutic agents. DPIs are recognized as suitable alternatives to pressurized metered dose inhalers for some patients, but the performance of DPI devices may vary according to a given patient's physiological condition. This variation can be associated with the necessary powder dispersion mechanism of each device. As such, much interest has focused on the development of efficient powder dispersion mechanisms, as this effectively minimizes the influence of interpatient variability. This article reviews DPI devices currently available, advantages of newly developed devices, outlines some requirements for future device design.     

Materials Strategies and Device Architectures of Emerging Power Supply Devices for Implantable Bioelectronics

Implantable bioelectronics represent an emerging technology that can be integrated into the human body for diagnostic and therapeutic functions. Power supply devices are an essential component of bioelectronics to ensure their robust performance. However, conventional power sources are usually bulky, rigid, and potentially contain hazardous constituent materials. The fact that biological organisms are soft, curvilinear, and have limited accommodation space poses new challenges for power supply systems to minimize the interface mismatch and still offer sufficient power to meet clinical‐grade applications. Here, recent advances in state‐of‐the‐art nonconventional power options for implantable electronics, specifically, miniaturized, flexible, or biodegradable power systems are reviewed. Material strategies and architectural design of a broad array of power devices are discussed, including energy storage systems (batteries and supercapacitors), power devices which harvest sources from the human body (biofuel cells, devices utilizing biopotentials, piezoelectric harvesters, triboelectric devices, and thermoelectric devices), and energy transfer devices which utilize sources in the surrounding environment (ultrasonic energy harvesters, inductive coupling/radiofrequency energy harvesters, and photovoltaic devices). Finally, future challenges and perspectives are given.     

Oxygen ion conductors

Ionic conductors have always provided a fascinating interdisciplinary field of study ever since their discovery by Faraday at the Royal Institution in London over 200 years ago. More recently, and particularly in the past decade, the pace of research has been rapid, driven by the requirements for new clean energy sources, sensors, and high energy density batteries.A very interesting subgroup of this class of materials are the oxides that display oxygen ion conductivity. As well as the intrinsic interest in these materials, there has been a continued drive for their development because of the promise of important technological devices such as the solid oxide fuel cell (SOFC), oxygen separation membranes, and membranes for the conversion of methane to syngas¹. All of these devices offer the potential of enormous commercial and ecological benefits provided suitable high performance materials can be developed. In this article we will review the materials currently under development for application in such devices with particular reference to some of the newly discovered oxide ion conductors.     

Advanced pyroelectric materials for energy harvesting and sensing applications

Heat energy is among the most wasted energy in the environment which is available in an ample quantity. So, developing new technology for harvesting and detecting wasted thermal energy to produce electrical energy which may be used as reliable energy sources for ultra-low power devices like nanogenerators and self-powered sensor applications. In this approach, pyroelectric energy harvesting technology has gained a huge attraction for application in power generation and sensing systems. Currently, a class of pyroelectric and piezoelectric materials has drawn enormous attraction because of its pyroelectric effect caused by spontaneous polarization and successful thermal energy harvesting for producing electrical energy for application in many sensor networks. This review makes a comprehensive summary of the significance and physical application of pyroelectric materials including single crystal, inorganic films, ceramics, organic materials, polymers, and composites as energy harvesting devices for scavenging thermal energy from surrounding for sensing devices. Finally, the perspective for next-generation self-powered sensor technologies is described.     

The use of energy windowing to discriminate SNM from NORM in radiation portal monitors

Energy windowing is an algorithmic alarm method that can be applied to plastic scintillator-based radiation portal monitor (RPM) systems to improve operational sensitivity to certain threat sources while reducing the alarm rates from naturally occurring radioactive material. Various implementations of energy windowing have been tested and documented by industry and at Pacific Northwest National Laboratory, and are available in commercial RPMs built by several manufacturers. Moreover, energy windowing is being used in many deployed RPMs to reduce nuisance alarms and improve operational sensitivity during the screening of cargo. This paper describes energy windowing algorithms and demonstrates how these algorithms succeed when applied to “controlled” experimental measurements and “real world” vehicle traffic data.     

Single‐Step Fluorocarbon Plasma Treatment‐Induced Wrinkle Structure for High‐Performance Triboelectric Nanogenerator

A triboelectric nanogenerator (TENG) has been thought to be a promising method to harvest energy from environment. To date, the utilization of surface structure and material modification has been considered the most effective way to increase its performance. In this work, a wrinkle structure based high‐performance TENG is presented. Using the fluorocarbon plasma treatment method, material modification and surface structure are introduced in one step. The output ability of TENG is dramatically enhanced. After the optimization of plasma treatment, the maximum current and surface charge density are 182 μA about 165 μC m^?2. Compared with untreated TENG, the wrinkle structure makes the current and surface charge density increase by 810% and 528%, separately. X‐ray photoelectron spectroscopy is employed to analyze the chemical modification mechanism of this fluorocarbon plasma treatment. Facilitated by its high output performance, this device could directly light 76 blue light emitting diodes under finger typing. The output electric energy could be stored then utilized to power a commercial calculator. As a result of the simple fabrication process and high output ability, devices fabricated using this method could bring forward practical applications using TENGs as power sources.     

Comparison of Spectral and Wavelet Estimators of Transfer Function for Linear Systems

We compare spectral and wavelet estimators of the response amplitude operator (RAO) of a linear system, with various input signals and added noise scenarios. The comparison is based on a model of a heaving buoy wave energy device (HBWED), which oscillates vertically as a single mode of vibration linear system. HBWEDs and other single degree of freedom wave energy devices such as oscillating wave surge convertors (OWSC) are currently deployed in the ocean, making such devices important systems to both model and analyse in some detail. The results of the comparison relate to any linear system. It was found that the wavelet estimator of the RAO offers no advantage over the spectral estimators if both input and response time series data are noise free and long time series are available. If there is noise on only the response time series, only the wavelet estimator or the spectral estimator that uses the cross-spectrum of the input and response signals in the numerator should be used. For the case of noise on only the input time series, only the spectral estimator that uses the cross-spectrum in the denominator gives a sensible estimate of the RAO. If both the input and response signals are corrupted with noise, a modification to both the input and response spectrum estimates can provide a good estimator of the RAO. A combination of wavelet and spectral methods is introduced as an alternative RAO estimator. The conclusions apply for autoregressive emulators of sea surface elevation, impulse, and pseudorandom binary sequences (PRBS) inputs. However, a wavelet estimator is needed in the special case of a chirp input where the signal has a continuously varying frequency.     

Estimation of vaccine efficacy in a repeated measures study under heterogeneity of exposure or susceptibility to infection

Vaccine efficacy (VE) is commonly estimated through proportional hazards modelling of the time to first infection or disease, even when the event of interest can recur. These methods can result in biased estimates when VE is heterogeneous across levels of exposure and susceptibility in subjects. These two factors are important sources of unmeasured heterogeneity, since they vary within and across areas, and often cannot be individually quantified. We propose an estimator of VE per exposure that accounts for heterogeneous susceptibility and exposure for a repeated measures study with binary recurrent outcomes. The estimator requires only information about the probability distribution of environmental exposures. Through simulation studies, we compare the properties of this estimator with proportional hazards estimation under the heterogeneity of exposure. The methods are applied to a reanalysis of a malaria vaccine trial in Brazil.     

Robust identification of transfer functions in the s- andz-domains

A frequency-domain maximum-likelihood estimator (MLE) for estimating the transfer function of linear continuous-time systems developed by J. Schoukens et al. (1988) assumes independent Gaussian noise on both the input and the output coefficients. A Gaussian frequency-domain MLE for transfer functions of linear continuous or discrete time invariant systems in an errors-in-variables model is presented. It is demonstrated that most of the properties of the estimator remain unchanged when it is applied to measured input and output Fourier coefficients corrupted with non-Gaussian errors. The result is a robust Gaussian frequency-domain estimator that is very useful for the practical identification of linear systems. The theoretical results are verified by simulations and experiments     

Information theory in optoelectronic systems: introduction to the feature.

There has been an explosion of recent interest concerning information theory in optoelectronic (OE) systems. This interest has been motivated in part by (1) the accelerating deployment of OE components into digital systems, (2) the blurring of the analog-digital interface within many OE applications, and (3) the increasing sophistication and complexity of computational tools. These trends are being driven by revolutionary improvements in both OE devices and electronic processors together with increasing demand for high-speed and high-capacity solutions. This feature addresses the application of information- and communication-theoretic concepts, algorithms, and techniques to important problems in OE system analysis and design.     

Flexible Thermoelectric Materials and Generators: Challenges and Innovations

The urgent need for ecofriendly, stable, long‐lifetime power sources is driving the booming market for miniaturized and integrated electronics, including wearable and medical implantable devices. Flexible thermoelectric materials and devices are receiving increasing attention, due to their capability to convert heat into electricity directly by conformably attaching them onto heat sources. Polymer‐based flexible thermoelectric materials are particularly fascinating because of their intrinsic flexibility, affordability, and low toxicity. There are other promising alternatives including inorganic‐based flexible thermoelectrics that have high energy‐conversion efficiency, large power output, and stability at relatively high temperature. Herein, the state‐of‐the‐art in the development of flexible thermoelectric materials and devices is summarized, including exploring the fundamentals behind the performance of flexible thermoelectric materials and devices by relating materials chemistry and physics to properties. By taking insights from carrier and phonon transport, the limitations of high‐performance flexible thermoelectric materials and the underlying mechanisms associated with each optimization strategy are highlighted. Finally, the remaining challenges in flexible thermoelectric materials are discussed in conclusion, and suggestions and a framework to guide future development are provided, which may pave the way for a bright future for flexible thermoelectric devices in the energy market.     

Data measurement in research information systems: metrics for the evaluation of data quality

In recent years, research information systems (RIS) have become an integral part of the university’s IT landscape. At the same time, many universities and research institutions are still working on the implementation of such information systems. Research information systems support institutions in the measurement, documentation, evaluation and communication of research activities. Implementing such integrative systems requires that institutions assure the quality of the information on research activities entered into them. Since many information and data sources are interwoven, these different data sources can have a negative impact on data quality in different research information systems. Because the topic is currently of interest to many institutions, the aim of the present paper is firstly to consider how data quality can be investigated in the context of RIS, and then to explain how various dimensions of data quality described in the literature can be measured in research information systems. Finally, a framework as a process flow according to UML activity diagram notation is developed for monitoring and improvement of the quality of these data; this framework can be implemented by technical personnel in universities and research institutions.     

Energy services for an electricity industry based on renewableenergy

This article investigates the potential for an entirely new structure for the electricity industry. This aims to provide energy services, such as light and heat, in the most economical way, by combining on-site generation with comprehensive energy efficiency measures. As well as leading to improved energy efficiency, it is shown how such an approach is more compatible with renewable sources of energy. It is also argued that such a structure would open up many profitable new investment opportunities to the electricity industry. The article explains why the traditional model for electricity systems fails to deliver both energy efficiency and renewable energy, and examines the effects that an energy services approach might have on the electricity industry if adopted on a wide scale. Factors that may cause the transition are also discussed. The article concludes that such a radically new approach may be the best way to deliver the large reductions in emissions required to mitigate climate change     

Micro/Nanostructured Materials for Sodium Ion Batteries and Capacitors

High‐efficiency energy storage technologies and devices have received considerable attention due to their ever‐increasing demand. Na‐related energy storage systems, sodium ion batteries (SIBs) and sodium ion capacitors (SICs), are regarded as promising candidates for large‐scale energy storage because of the abundant sources and low cost of sodium. In the last decade, many efforts, including structural and compositional optimization, effective modification of available materials, and design and exploration of new materials, have been made to promote the development of Na‐related energy storage systems. In this Review, the latest developments of micro/nanostructured electrode materials for advanced SIBs and SICs, especially the rational design of unique composites with high thermodynamic stabilities and fast kinetics during charge/discharge, are summarized. In addition to the recent achievements, the remaining challenges with respect to fundamental investigations and commercialized applications are discussed in detail. Finally, the prospects of sodium‐based energy storage systems are also described.     

Integer Programming Models for Deployment of Airport Baggage Screening Security Devices

Aviation security is an important problem of national interest and concern. Baggage screening security devices and operations at airports throughout the United States provide an important defense against terrorist actions targeted at commercial aircraft. Determining where to deploy such devices, and how to best use them can be quite challenging. This paper presents NP-complete decision problems concerning the deployment and utilization of baggage screening security devices. These problems incorporate three different deployment performance measures: uncovered baggage segments, uncovered flight segments, and uncovered passenger segments. Integer programming models are formulated to address optimization versions of these problems and to identify optimal baggage screening security device deployments (i.e., determine the number and type of baggage screening security devices that should be placed at different airports, and determining which baggage should be screened with such devices). The models are illustrated with an example that incorporates data extracted from the Official Airline Guide (OAG).     

Engineering Smart Nanofluidic Systems for Artificial Ion Channels and Ion Pumps: From Single-Pore to Multichannel Membranes

Biological ion channels and ion pumps with intricate ion transport functions widely exist in living organisms and play irreplaceable roles in almost all physiological functions. Nanofluidics provides exciting opportunities to mimic these working processes, which not only helps understand ion transport in biological systems but also paves the way for the applications of artificial devices in many valuable areas. Recent progress in the engineering of smart nanofluidic systems for artificial ion channels and ion pumps is summarized. The artificial systems range from chemically and structurally diverse lipid-membrane-based nanopores to robust and scalable solid-state nanopores. A generic strategy of gate location design is proposed. The single-pore-based platform concept can be rationally extended into multichannel membrane systems and shows unprecedented potential in many application areas, such as single-molecule analysis, smart mass delivery, and energy conversion. Finally, some present underpinning issues that need to be addressed are discussed.