Detecting the Presence of Electronic Devices in Smart Homes Using Harmonic Radar Technology

Data about users is collected constantly by phones, cameras, Internet websites, and others. The advent of so-called ‘Smart Things’ now enable ever-more sensitive data to be collected inside that most private of spaces: the home. The first step in helping users regain control of their information (inside their home) is to alert them to the presence of potentially unwanted electronics. In this paper, we present a system that could help homeowners (or home dwellers) find electronic devices in their living space. Specifically, we demonstrate the use of harmonic radars (sometimes called nonlinear junction detectors), which have also been used in applications ranging from explosives detection to insect tracking. We adapt this radar technology to detect consumer electronics in a home setting and show that we can indeed accurately detect the presence of even ‘simple’ electronic devices like a smart lightbulb. We evaluate the performance of our radar in both wired and over-the-air transmission scenarios.

Optical metasurfaces for generating and manipulating optical vortex beams

Optical vortices (OVs) carrying orbital angular momentum (OAM) have attracted considerable interest in the field of optics and photonics owing to their peculiar optical features and extra degree of freedom for carrying information. Although there have been significant efforts to realize OVs using conventional optics, it is limited by large volume, high cost, and lack of design flexibility. Optical metasurfaces have recently attracted tremendous interest due to their unprecedented capability in the manipulation of the amplitude, phase, polarization, and frequency of light at a subwavelength scale. Optical metasurfaces have revolutionized design concepts in photonics, providing a new platform to develop ultrathin optical devices for the realization of OVs at subwavelength resolution. In this article, we will review the recent progress in optical metasurface-based OVs. We provide a comprehensive discussion on the optical manipulation of OVs, including OAM superposition, OAM sorting, OAM multiplexing, OAM holography, and nonlinear metasurfaces for OAM generation and manipulation. The rapid development of metasurface for OVs generation and manipulation will play an important role in many relevant research fields. We expect that metasurface will fuel the continuous progress of wearable and portable consumer electronics and optics where low-cost and miniaturized OAM related systems are in high demand.

Recent Progress in Flexible Multiferroics

A great deal of interest has grown in both academia and industry toward flexible multiferroics in the recent years. The coupling of ferromagnetic properties with ferroelectric properties in multiferroic materials opens up many opportunities in applications such as magnetoelectric random access memories, magnetic field sensors, and energy harvesters. Multiferroic materials on a flexible platform bring an exciting opportunity for the next generation of consumer electronics owing to their unique characteristics of wearability, portability, and weight reduction. However, the fabrication of flexible multiferroic devices is still a great challenge due to various technical difficulties, including the requirement of high growth temperature of the oxide-based multiferroic materials, their lattice mismatch with the flexible substrates, and the brittleness of the functional layers. In this review article, we will discuss different methods of fabricating flexible or even freestanding oxide films to achieve flexible electronics. This article will address the benefits and challenges of each synthesis method in terms of interlayer interactions and growth parameters. Furthermore, the article will include an account of the possible bending limits of different flexible substrates without degrading the properties of the functional layer. Finally, we will address the challenges, opportunities, and future research directions in flexible multiferroics.

Impact of Intermediary and Seller Trust on Consumer Repurchase and E-WOM Intentions

This study investigates the impact of intermediary and seller trust on consumers' repurchase intention and electronic word-of-mouth (e-WOM) intention. A total of 337 consumers with online-buying experience were surveyed using a self-administered questionnaire. For the research purpose, a model was developed and tested using the PLS-SEM technique. In this instance, trust in a competent intermediary is formed on perceived benevolence and integrity. The moderating roles of demographics and purchase frequency were tested using a multigroup analysis. The results strongly support the research model, indicating that: (1) trust in competent intermediaries has a significant influence on consumers’ repurchase and e-WOM intention; (2) trust in consumer electronics (CE) sellers has an influence on repurchase intention but not e-WOM intention; and (3) age, gender positively affect the trust transference process, while purchase frequency affects e-WOM intention. This research presents new theoretical and managerial implications for online electronics marketing.

Thermal Conductivity Determination of Ga-In Alloys for Thermal Interface Materials Design

Thermal interface material (TIM) that exists in a liquid state at the service temperature enables efficient heat transfer across two adjacent surfaces in electronic applications. In this work, the thermal conductivities of different phase regions in the Ga-In system at various compositions and temperatures are measured for the first time. A modified comparative cut bar technique is used for the measurement of the thermal conductivities of GaxIn1−x (x = 0, 0.1, 0.214, 0.3, and 0.9) alloys at 40, 60, 80, and 100 °C, the temperatures commonly encountered in consumer electronics. The thermal conductivity of liquid and semi-liquid (liquid + β) Ga-In alloys are higher than most of the TIM’s currently used in consumer electronics. These measured quantities, along with the available experimental data from literature, served as input for the thermal conductivity parameter optimization using the CALPHAD (calculation of phase diagrams) method for pure elements, solution phase, and two-phase region. A set of self-consistent parameters for the description of the thermal conductivity of the Ga-In system is obtained. There is good agreement between the measured and calculated thermal conductivities for all of the phases. Due to their ease of manufacturing and high thermal conductivity, liquid/semi-liquid Ga-In alloys have significant potential for TIM in consumer electronics.

Optimized Interfaces in Anti-Perovskite Electrolyte-Based Solid-State Lithium Metal Batteries for Enhanced Performance

Solid-state lithium metal batteries have attracted broad interest as a promising energy storage technology because of the high energy density and enhanced safety that are highly desired in the markets of consumer electronics and electric vehicles. However, there are still many challenges before the practical application of the new battery. One of the major challenges is the poor interface between lithium metal electrodes and solid electrolytes, which eventually lead to the exceptionally high internal resistance of the cells and limited output. The interface issue arises largely due to the poor contact between solid and solid, and the mechanical/electrochemical instability of the interface. In this work, an in situ “welding” strategy is developed to address the interfacial issue in solid-state batteries. Microliter-level of liquid electrolyte is transformed into an organic–inorganic composite buffer layer, offering a flexible and stable interface and promoting enhanced electrochemical performance. Symmetric lithium–metal batteries with the new interface demonstrate good cycling performance for 400 h and withstand the current density of 0.4 mA cm−2. Full batteries developed with lithium–metal anode and LiFePO4 cathode also demonstrate significantly improved cycling endurance and capacity retention.

Development of empirically based customer-derived positioning taxonomy for consumer electronics sector in the Indian emerging market

PurposeAn Indian emerging market positioning taxonomy has been developed in response to the literature review's findings that existing positioning typologies/taxonomies are based on managerial perspectives rather than consumer/customer perceptions and are only developed for advanced countries.Design/methodology/approachThis study employs a three-step process for developing and validating a scale in order to conduct its research. In the first phase, items are generated and selected based on a literature review, focus groups and expert opinion. Exploratory factor analysis is used to fine-tune the scale in the second phase. Phase 3 uses CFA to establish convergent, discriminant and nomological validity through the use of CFA.FindingsA consumer-based taxonomy of positioning strategies were developed as a result of the research. Six distinct positioning strategies emerged that was named (1) Value for Money, (2) Functional (3) Premiumisation, (4) Promotional Campaign, (5) Brand Name (6) Visual Aesthetics.Research limitations/implicationsDeveloping and validating measurement scales will be made easier with the help of this paper. Target populations, industry and geography selection and a cross-sectional time horizon are just a few of the study's drawbacks.Practical implicationsThe study's practical implications include six factors/strategies that managers, advertising executives and marketing experts of consumer electronics companies in the Indian emerging market could use to position their products, resulting in the overall success of their organisations.Originality/valueThis study adds to the marketing literature by providing a solid theoretical foundation and a validated instrument for operationalising positioning strategies.

Biaxial FBAR Magnetic Sensor Based on Fe80Ga20 Anisotropic ΔE Effect

With the increasing application of personal navigation system in consumer electronics, the demand for multi-axis magnetic sensors based on MEMS is growing. We report a biaxial MEMS DC magnetic sensor consisting of an Mo/AlN/Fe80Ga20 film bulk acoustic resonator (FBAR), with anisotropy ΔE effect-based sensing principle. Different from the previously reported one-dimensional magnetic sensor based on the ΔE effect, the anisotropic ΔE effect was used to realize in-plane and out-of-plane two-dimensional magnetic field responses on a discrete sensor, and the sensor had two readout methods: resonant frequency f and return loss S11. The magnetic sensor realized the resonant frequency f shifted by 1.03 MHz and 0.2 MHz in the 567 Oe in-plane magnetic field and 720 Oe out-of-plane magnetic field, respectively, and the S11 changes by -30.2 dB and -0.92 dB. As the applied magnetic field increases, the -3 dB bandwidth quality factor Q3dB of the S11 curve gradually increases, and its maximum values in the in-plane and out-of-plane magnetic fields are 77143 and 1828, respectively, which reduces the detection limit of the magnetic sensor. The resonant magnetic sensor has stable high linear temperature and frequency drift characteristics, and its temperature frequency coefficient is -48.7 ppm/℃.

Adoption Pathways for DC Power Distribution in Buildings

Driven by the proliferation of DC energy sources and DC end-use devices (e.g., photovoltaics, battery storage, solid-state lighting, and consumer electronics), DC power distribution in buildings has recently emerged as a path to improved efficiency, resilience, and cost savings in the transitioning building sector. Despite these important benefits, there are several technological and market barriers impeding the development of DC distribution, which have kept this technology at the demonstration phase. This paper identifies specific end-use cases for which DC distribution in buildings is viable today. We evaluate their technology and market readiness, as well as their efficiency, cost, and resiliency benefits while addressing implementation barriers. The paper starts with a technology review, followed by a comprehensive market assessment, in which we analyze DC distribution field deployments and their end-use characteristics. We also conduct a survey of DC power and building professionals through on-site visits and phone interviews and summarize lessons learned and recommendations. In addition, the paper includes a novel efficiency analysis, in which we quantify energy savings from DC distribution for different end-use categories. Based on our findings, we present specific adoption pathways for DC in buildings that can be implemented today, and for each pathway we identify challenges and offer recommendations for the research and building community.