Extremely durable electrical impedance tomography-based soft and ultrathin wearable e-skin for three-dimensional tactile interfaces.

In the rapidly evolving field of human-machine interfaces (HMIs), high-resolution wearable electronic skin (e-skin) is essential for user interaction. However, traditional array-structured tactile interfaces require increased number of interconnects, while soft material-based computational methods have limited functionalities. Here, we introduce a thin and soft e-skin for tactile interfaces, offering high mapping capabilities through electrical impedance tomography (EIT).

Wafer-Scale Replication of Plasmonic Nanostructures via Microbubbles for Nanophotonics.

Quasi-3D plasmonic nanostructures are in high demand for their ability to manipulate and enhance light-matter interactions at subwavelength scales, making them promising building blocks for diverse nanophotonic devices. Despite their potential, the integration of these nanostructures with optical sensors and imaging systems on a large scale poses challenges. Here, a robust technique for the rapid, scalable, and seamless replication of quasi-3D plasmonic nanostructures is presented straight from their production wafers using a microbubble process.

Mechanical regulation to interfacial thermal transport in GaN/diamond heterostructures for thermal switch.

Gallium nitride offers an ideal material platform for next-generation high-power electronics devices, which enable a spectrum of applications. The thermal management of the ever-growing power density has become a major bottleneck in the performance, reliability, and lifetime of the devices. GaN/diamond heterostructures are usually adopted to facilitate heat dissipation, given the extraordinary thermal conduction properties of diamonds.

Spongy Ag Foam for Soft and Stretchable Strain Gauges.

Strain gauges, particularly for wearable sensing applications, require a high degree of stretchability, softness, sensitivity, selectivity, and linearity. They must also steer clear of challenges such as mechanical and electrical hysteresis, overshoot behavior, and slow response/recovery times. However, current strain gauges face challenges in satisfying all of these requirements at once due to the inevitable trade-offs between these properties.

Reorientation of Hydrogen Bonds Renders Unusual Enhancement in Thermal Transport of Water in Nanoconfined Environments.

Liquid confined in a nanochannel or nanotube has exhibited a superfast transport phenomenon, providing an ideal heat and mass transfer platform to meet the increasingly stringent challenge of thermal management in developing high-power-density nanoelectronics and nanochips. However, understanding the thermal transport of confined liquid is currently lacking and is speculated to be fundamentally different from that of bulk counterparts due to the unprecedented thermodynamics of liquid in nanoconfined environments. Here, we report that the thermal conductivity of water confined in a silica nanotube is nearly 2-fold as that of bulk status.

Elastocapillary rolling transfer weaves soft materials to spatial structures.

Spatial structures of soft materials have attracted great attention because of emerging applications in wearable electronics, biomedical devices, and soft robotics, but there are no facile technologies available to assemble the soft materials into spatial structures. Here, we report a mechanical transfer route enabled by the rotational motion of curved substrates relative to the soft materials on liquid surface. This transfer can weave soft materials into a broad variety of spatial structures with controllable global weaving chirality and orders and could also produce local ear-like folds with programmable numbers and distributions.

A Nanoconfined Water-Ion Coordination Network for Flexible Energy-Dissipation Devices.

Water-ion interaction in a nanoconfined environment that deeply constrains spatial freedoms of local atomistic motion with unconventional coupling mechanisms beyond that in a free, bulk state is essential to spark designs of a broad spectrum of nanofluidic devices with unique properties and functionalities. Here, it is reported that the interaction between ions and water molecules in a hydrophobic nanopore forms a coordination network with an interaction density that is nearly fourfold that of the bulk counterpart. Such strong interaction facilitates the connectivity of the water-ion network and is uncovered by corroborating the formation of ion clusters and the reduction of particle dynamics.

Ultra-High Interfacial Thermal Conductance via Double hBN Encapsulation for Efficient Thermal Management of 2D Electronics.

Heat dissipation is a major limitation of high-performance electronics. This is especially important in emerging nanoelectronic devices consisting of ultra-thin layers, heterostructures, and interfaces, where enhancement in thermal transport is highly desired. Here, ultra-high interfacial thermal conductance in encapsulated van der Waals (vdW) heterostructures with single-layer transition metal dichalcogenides MX (MoS , WSe , WS ) sandwiched between two hexagonal boron nitride (hBN) layers is reported.

Fabrication of gold-doped crystalline-silicon nanomembrane-based wearable temperature sensor.

Wearable temperature sensors with high thermal sensitivity are required for precise and continuous body temperature monitoring. Here, we present a protocol for fabricating a thin, stretchable, and ultrahigh thermal-sensitive wearable sensor based on gold-doped crystalline-silicon nanomembrane (SiNM). We provide detailed steps of gold doping technique to SiNM and fabrication processes for gold-doped crystalline-SiNM based wearable temperature sensor.

Mechanical Janus Structures by Soft-Hard Material Integration.

Engineering Janus structures that possess anisotropic features in functions have attracted growing attention for a wide range of applications in sensors, catalysis, and biomedicine, and are yet usually designed at the nanoscale with distinct physical or chemical functionalities in their opposite sides. Inspired by the seamless integration of soft and hard materials in biological structures, here a mechanical Janus structure composed of soft and hard materials with a dramatic difference in mechanical properties at an additively manufacturable macroscale is presented. In the combination of extensive experimental, theoretical, and computational studies, the design principle of soft-hard materials integrated mechanical Janus structures is established and their unique rotation mechanism is addressed.

Infectious hematopoietic necrosis virus (IHNV) nucleoprotein amino acid residues affect viral virulence and immunogenicity in rainbow trout (Oncorhynchus mykiss).

This study compared the N protein sequences of genotype J with other genotypes of IHNV to select amino acid residues that may be related to the change in viral virulence. The recombinant viruses containing different mutation sites were rescued by alanine scanning mutagenesis and the reverse genetic system. The nine recombinant virus strains obtained in this work were named rIHNV-N, rIHNV-N, rIHNV-N, rIHNV-N, rIHNV-N, rIHNV-N, rIHNV-N, rIHNV-N, and rIHNV-N.

Immunological Effects of Recombinant Expressing IHNV G Protein and Rainbow Trout () Chemokine CK6 as an Oral Vaccine.

IHNV is a virus that infects salmonids and causes serious economic damage to the salmonid farming industry. There is no specific treatment for the disease caused by this pathogen and the main preventive measure is vaccination, but this is only possible for small groups of individuals. Therefore, it is important to investigate new oral vaccines to prevent IHNV.

Electrically Suppressed Outflow of Confined Liquid in Hydrophobic Nanopores.

Confining liquid in a hydrophobic nanoenvironment has enabled a broad spectrum of applications in biomedical sensors, mechanical actuators, and energy storage and converters, where the outflow of confined liquid is spontaneous and fast due to the intrinsic hydrophobic nature of nanopores with extremely low interfacial friction, challenging design capacity and control tolerance of structures and devices. Here, we present a facile approach of suppressing the outflow of water confined in hydrophobic nanopores with an electric field. Extensive molecular dynamics simulations show that the presence of an electric field could significantly strengthen hydrogen bonds and retard degradations of the associated networks during the outflow.

Printable and Highly Stretchable Viscoelastic Conductors with Kinematically Reconstructed Conductive Pathways.

Printable and stretchable conductors based on metallic-filler-reinforced polymer composites that can maintain high electrical conductivity at large strains are essential for emerging applications in wearable electronics, soft robotics, and bio-integrated devices. Regulating microstructures of conductive fillers during mechanical deformations is the key to reconstructing the conductive pathway and retaining high electrical conductivity, which has proven to be challenging. Here, it is reported that Ag flakes can spontaneously reorganize inside a viscoelastic, liquid-like polymer matrix by cyclic mechanical stretching, resulting in reconstructed microstructures and forming highly efficient and stable conductive pathways.

Cyclic swelling enabled, electrically conductive 3D porous structures for microfluidic urinalysis devices.

Urinalysis is a simple and non-invasive approach for the diagnosis and monitoring of organ health and also is often used as a facile technique in assessment of substance abuse. However, quantitative urinalysis is predominantly limited to clinical laboratories. Here, we present an electrical sensing based, reusable, cellular microfluidic device that offers a fast urinalysis through quantitative reading of the electrical signals.

Pattern transfer of large-scale thin membranes with controllable self-delamination interface for integrated functional systems.

Direct transfer of pre-patterned device-grade nano-to-microscale materials highly benefits many existing and potential, high performance, heterogeneously integrated functional systems over conventional lithography-based microfabrication. We present, in combined theory and experiment, a self-delamination-driven pattern transfer of a single crystalline silicon thin membrane via well-controlled interfacial design in liquid media. This pattern transfer allows the usage of an intermediate or mediator substrate where both front and back sides of a thin membrane are capable of being integrated with standard lithographical processing, thereby achieving deterministic assembly of the thin membrane into a multi-functional system.

Ultrahigh Sensitive Au-Doped Silicon Nanomembrane Based Wearable Sensor Arrays for Continuous Skin Temperature Monitoring with High Precision.

Monitoring the body temperature with high accuracy provides a fast, facile, yet powerful route about the human body in a wide range of health information standards. Here, the first ever ultrasensitive and stretchable gold-doped silicon nanomembrane (Au-doped SiNM) epidermal temperature sensor array is introduced. The ultrasensitivity is achieved by shifting freeze-out region to intrinsic region in carrier density and modulation of fermi energy level of p-type SiNM through the development of a novel gold-doping strategy.

Transferable, Deep-Learning-Driven Fast Prediction and Design of Thermal Transport in Mechanically Stretched Graphene Flakes.

Piling graphene sheets into a bulk form is essential for achieving massive applications of graphene in flexible structures and devices, and the arbitrary shape, random distributions, and adjacent overlaps of graphene sheets are yet challenging the prediction of its fundamental properties that are strongly coupled by mechanical strength and thermal or electronic transport. Here, we present a deep neural network (DNN)-based machine learning (ML) approach that enables the prediction of thermal conductivity of piled graphene structures with a broad range of geometric configurations and dimensions in response to external mechanical loading. A physics-informed pixel value matrix is developed to capture the key geometric features of piled graphene structures and is incorporated into the DNN to train the ML model with the only training data ratio of 12.

All-printed stretchable corneal sensor on soft contact lenses for noninvasive and painless ocular electrodiagnosis.

Electroretinogram examinations serve as routine clinical procedures in ophthalmology for the diagnosis and management of many ocular diseases. However, the rigid form factor of current corneal sensors produces a mismatch with the soft, curvilinear, and exceptionally sensitive human cornea, which typically requires the use of topical anesthesia and a speculum for pain management and safety. Here we report a design of an all-printed stretchable corneal sensor built on commercially-available disposable soft contact lenses that can intimately and non-invasively interface with the corneal surface of human eyes.

Experimental and Computational Investigation of Layer-Dependent Thermal Conductivities and Interfacial Thermal Conductance of One- to Three-Layer WSe.

Two-dimensional materials such as graphene and transition metal dichalcogenides (TMDCs) have received extensive research interest and investigations in the past decade. In this research, we used a refined opto-thermal Raman technique to explore the thermal transport properties of one popular TMDC material WSe, in the single-layer (1L), bilayer (2L), and trilayer (3L) forms. This measurement technique is direct without additional processing to the material, and the absorption coefficient of WSe is discovered during the measurement process to further increase this technique's precision.

Spontaneous outflow efficiency of confined liquid in hydrophobic nanopores.

The suspension of nanoporous particles in a nonwetting liquid provides a unique solution to the crux of superfluid, sensing, and energy conversion, yet is challenged by the incomplete outflow of intruded liquid out of nanopores for the system reusability. We report that a continuous and spontaneous liquid outflow from hydrophobic nanopores with high and stable efficiency can be achieved by regulating the confinement of solid-liquid interactions with functionalized nanopores or/and liquids. Full-scale molecular-dynamics simulations reveal that the grafted silyl chains on nanopore wall surfaces will promote the hydrophobic confinement of liquid molecules and facilitate the molecular outflow; by contrast, the introduction of ions in the liquid weakens the hydrophobic confinement and congests the molecular outflow.

Solution Evaporation-Driven Crumpling and Assembling of Large-Accessible-Space, High-Mechanical-Strength Graphene/Carbon Nanotube Composite Nanoparticles.

Crumpled graphene particles that are converted and assembled from 2D planar graphene sheets create a subtle material platform for widespread applications of graphene in a low-cost and scalable manner. However, such crumpled particles are suffering from small spatial availabilities in geometry and low strength in mechanical deformation due to the limited numbers and stabilities of connections among individual deformed graphene. Herein, we report, in both theoretical analysis and large-scale atomistic simulations, that a crumpled graphene composite nanoparticle with large accessible space and high mechanical strength can be achieved by encapsulating folded carbon nanotubes (CNTs) inside via a solvent evaporation-induced assembly approach.

Bioresorbable, Miniaturized Porous Silicon Needles on a Flexible Water-Soluble Backing for Unobtrusive, Sustained Delivery of Chemotherapy.

Conventional melanoma therapies suffer from the toxicity and side effects of repeated treatments due to the aggressive and recurrent nature of melanoma cells. Less-invasive topical chemotherapies by utilizing polymeric microneedles have emerged as an alternative, but the sustained, long-lasting release of drug cargos remains challenging. In addition, the size of the microneedles is relatively bulky for the small, curvilinear, and exceptionally sensitive cornea for the treatment of ocular melanoma.