Emerging Thermal Technology Enabled Augmented Reality

In the past decade, remarkable progress has been made in the domain of augmented reality/virtual reality (AR/VR). The need for realistic and immersive augmentation has propelled the development of haptics interfaces-enabled AR/VR. The haptics interfaces facilitate direct interaction and manipulation with both real and virtual objects, thus augmenting the perception and experiences of the users. The level of augmentation can be significantly improved by thermal stimulation or sensing, which facilitates a higher degree of object identification and discrimination. This review discusses the thermal technology-enabled augmented reality and summarizes the recent progress in the development of different thermal technology such as thermal haptics including thermo-resistive heater and Peltier devices, thermal sensors including resistive, pyroelectric, and thermoelectric sensors, which can be utilized to improve the realism of augmentation. The fundamental mechanism, design strategies, and the rational guidelines for the adoption of these technologies in AR/VR is explicitly discussed. The conclusion provides an outlook on the existing challenges and outlines the future roadmap for the realization of next-generation thermo-haptics enabled augmented reality.     

Vehicular networks with security and trust management solutions: proposed secured message exchange via blockchain technology

Wireless Networks - In vehicular ad hoc networks (VANET), effective trust establishment with authentication is an important requirement. Trust management among communicating vehicles is significant...     

Emerging Soft Conductors for Bioelectronic Interfaces

Bidirectional interfacing between electrodes and biological systems has enabled diagnostics and therapeutics in modern medicine; however, the inherent dissimilarity between the soft, ion‐rich, dynamic biological tissues and the rigid, dry, static electronic systems hinders the establishment of effective and reliable bioelectronic interfaces. In the past decade, the scope of flexible/stretchable electronics has been broadened into bioelectronics owing to the need of implementation of various biocompatible soft conductors. Herein, the basic requirements for the construction of both epidermal and implantable bioelectronic interfaces utilizing soft materials are discussed, the most recent progress in the development of soft conductors, which are customized to interface with skin and other tissues, are summarized. An outlook into the remaining obstacles is provided and possible strategies to facilitate technological advances in bioelectronics are also outlined.     

Illumination and scale invariant relevant visual features with hypergraph-based learning for multi-shot person re-identification

Person re-identification which aims at matching people across disjoint cameras has received increasing attention due to the widespread use of video surveillance applications. Existing methods concentrate either on robust feature extraction or view-invariant feature transformation. However, the extracted features suffer from various limitations such as color inconsistency and scale variations. Besides, during matching, a probe is compared against each gallery instance which represents only the pairwise relationship and ignores the high order relationship among them. To address these issues, we propose a multi-shot person re-identification framework that first performs a preprocessing task on images to address illumination variations for maintaining the color consistency. Subsequently, we formulate an approach to handle scale variations in the pedestrian appearances for keeping them with relatively a fixed scale ratio. Overlapped visual patches representing appearance cues are then extracted from the processed images. A structured multi-class feature selection approach is employed to select a set of relevant patches that simultaneously discriminates all distinct persons. These selected patches use a hypergraph to represent the visual association among a probe and gallery images. Finally, for matching, we formulate a hypergraph-based learning scheme, which considers both the pairwise and high-order association among the probe and gallery images. The hypergraph structure is then optimized to yield an improved similarity score for a probe against each gallery instance. The effectiveness of our proposed framework is validated on three public datasets and comparison with state-of-the-art methods shows the superior performance of our framework.

     

A low complexity hardware architecture of K-means algorithm for real-time satellite image segmentation

Multimedia Tools and Applications - The Real time monitoring of forest area, coastal regions, sea, river basins, nation borders etc. helps in quick determination of devastations caused by natural...     

Influence of nitrogen on the growth of vertical graphene nanosheets under plasma

We have investigated the effect of nitrogen (N₂) as a carrier gas on the growth of vertical graphene nanosheets (VGN) by plasma-enhanced chemical vapor deposition. It is demonstrated that addition of nitrogen gas with a hydrocarbon precursor can enhance the nucleation and growth rate of graphitic base layer as well as vertical sheets. Additionally, nitrogen gas can simultaneously act as an etchant as well as a dopant. Variation in the density of vertical sheets is found, and it increased initially thereafter decreased at higher nitrogen concentration. Furthermore, VGN exhibit sheet resistance from 0.89 to 1.89 KΩ/□ and mobility from 8.05 to 20.14 cm²/V-s, depending on the morphology and type of carrier concentration. These results reveal that the surface morphology and electronic properties of VGN can be tuned by incorporation of nitrogen gas during the growth.     

Highly Transparent,Stretchable, and Self‐Healing Ionic‐Skin Triboelectric Nanogenerators for Energy Harvesting and Touch Applications

Recently developed triboelectric nanogenerators (TENGs) act as a promising power source for self‐powered electronic devices. However, the majority of TENGs are fabricated using metallic electrodes and cannot achieve high stretchability and transparency, simultaneously. Here, slime‐based ionic conductors are used as transparent current‐collecting layers of TENG, thus significantly enhancing their energy generation, stretchability, transparency, and instilling self‐healing characteristics. This is the first demonstration of using an ionic conductor as the current collector in a mechanical energy harvester. The resulting ionic‐skin TENG (IS‐TENG) has a transparency of 92% transmittance, and its energy‐harvesting performance is 12 times higher than that of the silver‐based electronic current collectors. In addition, they are capable of enduring a uniaxial strain up to 700%, giving the highest performance compared to all other transparent and stretchable mechanical‐energy harvesters. Additionally, this is the first demonstration of an autonomously self‐healing TENG that can recover its performance even after 300 times of complete bifurcation. The IS‐TENG represents the first prototype of a highly deformable and transparent power source that is able to autonomously self‐heal quickly and repeatedly at room temperature, and thus can be used as a power supply for digital watches, touch sensors, artificial intelligence, and biointegrated electronics.     

Dendrite-Free Potassium Metal Anodes in a Carbonate Electrolyte

Potassium (K) metal anodes suffer from a challenging problem of dendrite growth. Here, it is demonstrated that a tailored current collector will stabilize the metal plating–stripping behavior even with a conventional KPF₆-carbonate electrolyte. A 3D copper current collector is functionalized with partially reduced graphene oxide to create a potassiophilic surface, the electrode being denoted as rGO@3D-Cu. Potassiophilic versus potassiophobic experiments demonstrate that molten K fully wets rGO@3D-Cu after 6 s, but does not wet unfunctionalized 3D-Cu. Electrochemically, a unique synergy is achieved that is driven by interfacial tension and geometry: the adherent rGO underlayer promotes 2D layer-by-layer (Frank–van der Merwe) metal film growth at early stages of plating, while the tortuous 3D-Cu electrode reduces the current density and geometrically frustrates dendrites. The rGO@3D-Cu symmetric cells and half-cells achieve state-of-the-art plating and stripping performance. The symmetric rGO@3D-Cu cells exhibit stable cycling at 0.1–2 mA cm⁻², while baseline Cu prematurely fails when the current reaches 0.5 mA cm⁻². The half-cells cells of rGO@3D-Cu (no K reservoir) are stable at 0.5 mA cm⁻² for 10 000 min (100 cycles), and at 1 mA cm⁻² for 5000 min. The baseline 3D-Cu, planar rGO@Cu, and planar Cu foil fails after 5110, 3012, and 1410 min, respectively.