DataSheet1_Application of a digital twin for highway tunnels based on multi-sensor and information fusion.docx

Due to the harsh environment of highway tunnels and frequent breakdowns of various detection sensors and surveillance devices, the operational management of highway tunnels lacks effective data support. This paper analyzes the characteristics of operational surveillance data in highway tunnels. It proposes a multimodal information fusion method based on CNN–LSTM–attention and designs and develops a digital twin for highway tunnel operations. The system addresses issues such as insufficient development and coordination of the technical architecture of operation control systems, weak information service capabilities, and insufficient data application capabilities. The system also lacks intelligent decision-making and control capabilities. The developed system achieves closed-loop management of “accurate perception–risk assessment–decision warning–emergency management” for highway tunnel operations based on data-driven approaches. The engineering demonstration application underscores the system’s capacity to enhance tunnel traffic safety, diminish tunnel management costs, and elevate tunnel driving comfort.</p

Facile Synthesis of Free-Standing Silicon Membranes with Three-Dimensional Nanoarchitecture for Anodes of Lithium Ion Batteries

We propose a facile method for synthesizing a novel Si membrane structure with good mechanical strength and three-dimensional (3D) configuration that is capable of accommodating the large volume changes associated with lithiation in lithium ion battery applications. The membrane electrodes demonstrated a reversible charge capacity as high as 2414 mAh/g after 100 cycles at current density of 0.1 C, maintaining 82.3% of the initial charge capacity. Moreover, the membrane electrodes showed superiority in function at high current density, indicating a charge capacity >1220 mAh/g even at 8 C. The high performance of the Si membrane anode is assigned to their characteristic 3D features, which is further supported by mechanical simulation that revealed the evolution of strain distribution in the membrane during lithiation reaction. This study could provide a model system for rational and precise design of the structure and dimensions of Si membrane structures for use in high-performance lithium ion batteries

Facile Synthesis of Free-Standing Silicon Membranes with Three-Dimensional Nanoarchitecture for Anodes of Lithium Ion Batteries

We propose a facile method for synthesizing a novel Si membrane structure with good mechanical strength and three-dimensional (3D) configuration that is capable of accommodating the large volume changes associated with lithiation in lithium ion battery applications. The membrane electrodes demonstrated a reversible charge capacity as high as 2414 mAh/g after 100 cycles at current density of 0.1 C, maintaining 82.3% of the initial charge capacity. Moreover, the membrane electrodes showed superiority in function at high current density, indicating a charge capacity >1220 mAh/g even at 8 C. The high performance of the Si membrane anode is assigned to their characteristic 3D features, which is further supported by mechanical simulation that revealed the evolution of strain distribution in the membrane during lithiation reaction. This study could provide a model system for rational and precise design of the structure and dimensions of Si membrane structures for use in high-performance lithium ion batteries

Modulated Degradation of Transient Electronic Devices through Multilayer Silk Fibroin Pockets

The recent introduction of transient, bioresorbable electronics into the field of electronic device design offers promise for the areas of medical implants and environmental monitors, where programmed loss of function and environmental resorption are advantageous characteristics. Materials challenges remain, however, in protecting the labile device components from degradation at faster than desirable rates. Here we introduce an indirect passivation strategy for transient electronic devices that consists of encapsulation in multiple air pockets fabricated from silk fibroin. This approach is investigated through the properties of silk as a diffusional barrier to water penetration, coupled with the degradation of magnesium-based devices in humid air. Finally, silk pockets are demonstrated to be useful for controlled modulation of device lifetime. This approach may provide additional future opportunities for silk utility due to the low immunogenicity of the material and its ability to stabilize labile biotherapeutic dopants

Kinetics and Chemistry of Hydrolysis of Ultrathin, Thermally Grown Layers of Silicon Oxide as Biofluid Barriers in Flexible Electronic Systems

Flexible electronic systems for bioimplants that offer long-term (multidecade) stability and safety in operation require thin, biocompatible layers that can prevent biofluid penetration. Recent work shows that ultrathin films of silicon dioxide thermally grown (TG-SiO₂) on device-grade silicon wafers and then released as transferrable barriers offer a remarkable set of attributes in this context. This paper examines the chemical stability of these materials in aqueous solutions with different combinations of chemistries that are present in biofluids. Systematic measurements reveal the dependence of the dissolution rate of TG-SiO₂ on concentrations of cations (Na⁺, K⁺, Mg²⁺, Ca²⁺) and anions (Cl^–, HPO₄^2–) at near-neutral pH. Certain results are consistent with previous studies on bulk samples of quartz and nanoparticles of amorphous silica; others reveal significant catalyzing effects associated with divalent cations at high pH and with specific anions at high ionic strength. In particular, Ca²⁺ and HPO₄^2– greatly enhance and silicic acid greatly reduces the rates. These findings establish foundational data of relevance to predicting lifetimes of implantable devices that use TG-SiO₂ as biofluid barriers, and of other classes of systems, such as environmental monitors, where encapsulation against water penetration is important

Quantitative Thermal Imaging of Single-Walled Carbon Nanotube Devices by Scanning Joule Expansion Microscopy

Electrical generation of heat in single-walled carbon nanotubes (SWNTs) and subsequent thermal transport into the surroundings can critically affect the design, operation, and reliability of electronic and optoelectronic devices based on these materials. Here we investigate such heat generation and transport characteristics in perfectly aligned, horizontal arrays of SWNTs integrated into transistor structures. We present quantitative assessments of local thermometry at individual SWNTs in these arrays, evaluated using scanning Joule expansion microscopy. Measurements at different applied voltages reveal electronic behaviors, including metallic and semiconducting responses, spatial variations in diameter or chirality, and localized defect sites. Analytical models, validated by measurements performed on different device structures at various conditions, enable accurate, quantitative extraction of temperature distributions at the level of individual SWNTs. Using current equipment, the spatial resolution and temperature precision are as good as ∼100 nm and ∼0.7 K, respectively

Optics and Nonlinear Buckling Mechanics in Large-Area, Highly Stretchable Arrays of Plasmonic Nanostructures

Large-scale, dense arrays of plasmonic nanodisks on low-modulus, high-elongation elastomeric substrates represent a class of tunable optical systems, with reversible ability to shift key optical resonances over a range of nearly 600 nm at near-infrared wavelengths. At the most extreme levels of mechanical deformation (strains >100%), nonlinear buckling processes transform initially planar arrays into three-dimensional configurations, in which the nanodisks rotate out of the plane to form linear arrays with “wavy” geometries. Analytical, finite-element, and finite-difference time-domain models capture not only the physics of these buckling processes, including all of the observed modes, but also the quantitative effects of these deformations on the plasmonic responses. The results have relevance to mechanically tunable optical systems, particularly to soft optical sensors that integrate on or in the human body

Biodegradable Elastomers and Silicon Nanomembranes/Nanoribbons for Stretchable, Transient Electronics, and Biosensors

Transient electronics represents an emerging class of technology that exploits materials and/or device constructs that are capable of physically disappearing or disintegrating in a controlled manner at programmed rates or times. Inorganic semiconductor nanomaterials such as silicon nanomembranes/nanoribbons provide attractive choices for active elements in transistors, diodes and other essential components of overall systems that dissolve completely by hydrolysis in biofluids or groundwater. We describe here materials, mechanics, and design layouts to achieve this type of technology in stretchable configurations with biodegradable elastomers for substrate/encapsulation layers. Experimental and theoretical results illuminate the mechanical properties under large strain deformation. Circuit characterization of complementary metal-oxide-semiconductor inverters and individual transistors under various levels of applied loads validates the design strategies. Examples of biosensors demonstrate possibilities for stretchable, transient devices in biomedical applications

Si/Ge Double-Layered Nanotube Array as a Lithium Ion Battery Anode

Problems related to tremendous volume changes associated with cycling and the low electron conductivity and ion diffusivity of Si represent major obstacles to its use in high-capacity anodes for lithium ion batteries. We have developed a group IVA based nanotube heterostructure array, consisting of a high-capacity Si inner layer and a highly conductive Ge outer layer, to yield both favorable mechanics and kinetics in battery applications. This type of Si/Ge double-layered nanotube array electrode exhibits improved electrochemical performances over the analogous homogeneous Si system, including stable capacity retention (85% after 50 cycles) and doubled capacity at a 3<i>C</i> rate. These results stem from reduced maximum hoop strain in the nanotubes, supported by theoretical mechanics modeling, and lowered activation energy barrier for Li diffusion. This electrode technology creates opportunities in the development of group IVA nanotube heterostructures for next generation lithium ion batteries

Dissolution Chemistry and Biocompatibility of Single-Crystalline Silicon Nanomembranes and Associated Materials for Transient Electronics

Single-crystalline silicon nanomembranes (Si NMs) represent a critically important class of material for high-performance forms of electronics that are capable of complete, controlled dissolution when immersed in water and/or biofluids, sometimes referred to as a type of “transient” electronics. The results reported here include the kinetics of hydrolysis of Si NMs in biofluids and various aqueous solutions through a range of relevant pH values, ionic concentrations and temperatures, and dependence on dopant types and concentrations. <i>In vitro</i> and <i>in vivo</i> investigations of Si NMs and other transient electronic materials demonstrate biocompatibility and bioresorption, thereby suggesting potential for envisioned applications in active, biodegradable electronic implants