Automobile Window Research Articles

Nanoporous Structure Fabrication on Glass Surfaces for Enhanced Glass Adhesion Using Hydrogen Fluoride Gas.

The bonding between glass and other materials plays a crucial role when glass is used in industrial products. In this study, we propose a new approach to enhance the bonding strength of glass with other materials by fabricating nanoscale porous structures on glass surfaces via a chemical reaction with hydrogen fluoride gas. Herein, we present a methodology for controlling the thickness of the porous structure, clarify the relationship between the thickness and adhesion strength, investigate the shape of the formed porous structure, and propose a method to control its shape. Our findings reveal that the fabricated porous structure greatly improves the adhesion strength of the adhesive owing to the microscopic anchoring effect induced by the penetration of the adhesive into the porous structure. This approach is expected to be applied to architectural and automobile window glasses, solar panels, sensor cover glasses of autonomous vehicles, display devices (including smartphones), and wearable devices.

52710 Automobile Window Film as a Dermatologic Intervention for Reducing Ultraviolet Radiation Exposure

52710 Automobile Window Film as a Dermatologic Intervention for Reducing Ultraviolet Radiation Exposure

Study on Shielding Effectiveness of High Transmittance Coating Film Glasses against Electromagnetic Pulse

This study investigated the shielding effectiveness (SE) of glass materials with conductive coatings by establishing a 3000 × 3000 × 3000 mm electromagnetic pulse (EMP)—shielded room according to the EMP shielding requirements in the US military standard MIL-STD-188-125-1. The EMP SE of conductive-coated glass samples was measured and verified with the broadband EMP conditions of 10 kHz∼1 GHz. The conductive thin film coating on the glass was made by mixing conductive materials, including In2O3, SnO2, Ta2O5, NbO, SiO2, TiO2, and Al2O3, at different ratios. The mixed solutions were then coated onto the glass targets to facilitate conductive continuity between the conductive oxides and the shielding metal structure. The glass samples had dimensions of 1000 × 600 mm, which had electrolytic conductivity σ = 4.0064 × 103∼4.7438 × 103 (S/cm), 74∼77% transmittance, and 6.4∼6.8 Ω/□ film resistance. The experimental results indicated that the glass had SE of 35∼40 dB under 1 GHz EMP, satisfying the US National Coordinating Center for Communications’ Level 3 shielding protection requirement of at least 30 dB. The glass attenuated energy density by more than 1000 times, which is equivalent to shielding over 97% of EMP energy. Accordingly, the glass materials can be used as high-transmittance conductive glass for windows of automobiles, vessels, and aircrafts to protect from EMPs.

Haze-Suppressed Wideband Light Shutter from Near Ultraviolet to Infrared Rays Utilizing Electrophoretic Carbon Black Particles.

Carbon black (CB) particles that can absorb from near ultraviolet to infrared rays are well dispersed into an isotropic dielectric liquid and their optical properties can be kept even under exposure to sunlight over a long time. The shutter which controls the position of CB particles by electrophoretic force can be applied to switchable light shutters for windows in buildings and automobiles for the purpose of energy savings. Here, a wideband light shutter with three terminal electrodes is proposed, exhibiting excellent dark (transmittance ≈1.4%) and transparent state (transmittance >60%). The device operates at a low field intensity of about 1Vµm-1 to obtain transparent state and its wide temperature range operation from -50 to 120°C is confirmed while conventional liquid crystal-based shutter cannot perform such levels due to a limited temperature range in the nematic phase. In addition, haze is minimized in a transparent state by adopting an insulation layer over electrodes and a solution is found to keep a transparent state without applying power. It is believed that the proposed broadband shutter with fast response time could open a new chapter in switchable windows owing to its low power consumption and working in a wide temperature range.

Effect of different types of mesogenic compounds with fluorine and cyano-group on the working temperature of polymer dispersed liquid crystal films

As a type of smart dimming film, polymer dispersed liquid crystal (PDLC) film can meet the functional requirements in fields of displays and smart windows, but its narrow working temperature range is far from satisfactory for outdoor applications. To solve this problem, two types of high-clearing point mesogenic compounds with different end groups were introduced and the effects of their chemical structure on the working temperature range of PDLC film were investigated. Results show that the PDLC film doped with 10 wt% fluorine-containing LC molecule (3F) has a low driving voltage (<36 V) at −20 °C, but its contrast ratio (CR) value at the high temperature is disappointing. Furthermore, by adding 10 wt% cyano LC molecule (3 N), the film maintains an excellent CR value (62) at 90 °C. This work provides theoretical guidance and experimental support for broadening the working temperature of PDLC films, which is an important factor for their applications in automobile smart windows.

Development and evaluation of physical properties of PLA matrix composites reinforced with SCB/CF fiber

Researchers are increasingly focusing on natural, biodegradable materials because of environmental concerns. Although natural fibers give less strength than synthetic fibers, but they still contain some specific properties. In this paper, we studied the fire and water resistance, density, and swelling behavior of sugarcane bagasse fiber and chicken feather fiber composites using polylactic acid (E-3051D) as a matrix for different weighing fractions of fiber viz. 03%, 06%, 09%, (03 + 05)%, (06 + 05)%, (09 + 05)% and for 3 mm thickness. The 300 mm × 300 mm panels were made using the compression molding. According to ASTM standards, an investigation was carried out on several physical characteristics, including density, moisture content, water absorption, linear swelling, and a flammability test. It was observed that 3% sugarcane bagasse and 5% chicken feather fiber are better for various applications, as further increments will affect the mechanical properties. It is a combination of natural fibers and biodegradable matrix material, which makes it ecofriendly with various applications such as in automobile interiors, packaging materials, wall panels, window and door frames, and roof sheets, but limited use in bathroom and kitchen areas.

Analysis of automobile window glass samples by k0-NAA and PIXE techniques for forensic applications

Analysis of automobile window glass samples by k0-NAA and PIXE techniques for forensic applications

Balanced electro-optical properties and off-axis haze performance of a polymer-dispersed liquid crystal film via refractive index matching.

As a type of smart dimming film, polymer-dispersed liquid crystals (PDLCs) show great prospects in the fields of indoor partition, electronic curtains, and automobile windows. However, its high off-axis haze greatly impacts the application scope. This obvious shortcoming is mainly caused by the serious mismatch between the effective refractive index of the liquid crystal (neff) and the refractive index of the polymer matrix (np) at large viewing angles. Thereby, factors affecting the viewing angle of a PDLC film are analyzed in this research, including the birefringence of the liquid crystal (Δn), film thickness, and the refractive index of the polymer matrix (np). Balanced electro-optical properties are guaranteed simultaneously. It is found that high on-state transmittance and low off-axis haze can be achieved at large viewing angles in the suggested optimized case where Δn is within the range of 0.1-0.13; the film thickness is between 20 μm and 15 μm; and np approaches no but the difference does not exceed 0.03.

Aerodynamic Super-Repellent Surfaces.

Repelling liquid drops from engineering surfaces has attracted great attention in a variety of applications. To achieve efficient liquid shedding, delicate surface textures are often introduced to sustain air pockets at the liquid-solid interface. However, those surfaces are prone to suffer from mechanical failure, which may bring reliability issues and thus limits their applications. Here, inspired by the aerodynamic Leidenfrost effect, we present that impacting drops are directionally repelled from smooth surfaces supplied with an exogenous air layer. Our theoretical analysis reveals that the synchronized nonwetting and oblique bouncing behavior is attributed to the aerodynamic force arising from the air layer. The versatility and practicability of our approach allow for drop repellency without the aid of any surface wettability treatment and also avoid the consideration of mechanical stability issues, which thereby provides a promising candidate for the applications that necessitate liquid shedding, e.g., resolve the problem of tiny raindrop adhesion on the automobile side window during driving.

The vibroacoustic characteristics and regulation rules of Panel–Cavity–Panel System controlled by Piezoelectric Shunt Oscillators with negative capacitors

Piezoelectric Shunt Oscillators (PSOs) are widely used in the passive and semi-active control of the vibration and acoustic radiation of flexible structures, due to PSOs’ high electromechanical coupling coefficients, robustness, effectiveness and adjustability at low frequencies. Panel–Cavity–Panel System (PCPS) is a common type of flexible structures, such as interior panels and windows of automobiles. In this paper, a theoretical model of PCPS controlled by PSOs and its vibration equations are established. The vibroacoustic characteristics of PCPS, including sound absorption coefficient (SAC), energy loss coefficient (ELC) and transmission loss (TL), are calculated using a unified mathematical form based on the vibroacoustic radiation impedance matrix, damping matrix and displacement response of PCPS, while a lumped parameter model of PCPS is derived to simplify the comprehension and extension of PCPS. Then the finite element simulation is used to calculate the vibroacoustic characteristics of the PCPS, which achieves good agreement with theoretical results, while three basic regulation modes are also summarized and verified. The regulation mechanism of PCPS controlled by PSOs is further analyzed by the velocity response of each panel. Finally, experiments of PCPS controlled by PSOs with negative capacitors are conducted in a standing wave tube, at non-eigenfrequencies ranging from 70 Hz to 220 Hz. It is found in experiments that PSOs with negative capacitor can increase the TL of PCPS about 8 dB to 25 dB, which depends on the target frequency. SAC and ELC can also be increased, which means less acoustic energy is reflected and more acoustic energy is dissipated in the shunt circuits.

Transparent Heat Shielding Properties of Core-Shell Structured Nanocrystalline CsxWO3@TiO2.

Nanocrystalline tungsten bronze is an excellent near-infrared absorbing material, which has a good potential application in the field of transparent heat shielding materials on windows of automobiles or buildings, but it exhibits serious instability in the actual environment, which hinders its further application. In this paper, we coated the CsxWO3 nanoparticles with TiO2 to prepare core-shell structured CsxWO3@TiO2, and its crystal structure and optical properties were studied. The results show that the surface of CsxWO3 nanoparticles is coated with a layer of TiO2 particles with the size of several nanometers, and the shell thickness can be adjusted by the amount of Ti source. The measurement of optical properties illustrates that TiO2-coated CsxWO3 exhibits good stability in actual environment, and its transparent heat shielding performance will decrease with the increase in TiO2 shell thickness. This work provides a new route to promote the applications of tungsten bronze as heat shielding materials.

Semitransparent Perovskite Solar Cells with Enhanced Light Utilization Efficiencies by Transferable Ag Nanogrid Electrodes

Solar cells that are semitransparent and highly efficient can find diverse applications in automobile windows, building walls, and wearable devices. Here, we present a semitransparent perovskite thin-film solar cell with an Ag nanogrid transparent electrode, where electrospun poly(ethylene oxide) (PEO) nanofibers are used as an etching mask. Directional electrospinning has allowed us to obtain a grid-shaped electrode of well-aligned Ag nanogrids. The performance of transparent electrodes can be controlled by the electrospinning conditions and the choice of substrate materials. We theoretically analyze the transmittance and sheet resistance of the electrode. Furthermore, transferable Ag nanogrid transparent electrodes are fabricated on poly(dimethylsiloxane) (PDMS) substrates for application in semitransparent perovskite solar cells. Using an electrode that shows a high transmittance (92.7%) with a low sheet resistance (18.0 Ω·sq-1), a semitransparent perovskite thin-film solar cell demonstrates average visible wavelength transmittance, power conversion efficiency, and light utilization efficiency rates as high as 25.2, 12.7, and 3.21%, respectively.

Visibly Clear Radiative Cooling Metamaterials for Enhanced Thermal Management in Solar Cells and Windows

AbstractThe study of transparent daytime radiative cooling with no additional energy consumption is a promising area of research. Its applications include solar cells and building and automobile windows that are prone to heating issues. Ubiquitous applications necessitate the development of metamaterials with high mechanical flexibility in a scalable manner while overcoming translucence. In this study, visibly clear and flexible radiative cooling metamaterials have been developed using a newly designed optical modulator filled into randomly distributed silica aerogel microparticles in a silicone elastomer. The optical modulator effectively suppresses visible light scattering, thus enabling higher loading of silica aerogel microparticles while securing visible clarity. The significant suppression of the rise in temperature by the metamaterial is verified using both indoor and outdoor experiments. The visibly clear metamaterials deployed in solar cells and windows can effectively suppress the rise in temperature under solar irradiation, thereby mitigating the performance degradation of solar cells by heating issues and suppressing the rise in temperature of indoor air.

Preparation of Water-Repellent Film on a Plastic Plate by Unbalanced Radio-Frequency Magnetron Plasma Sputtering Using PTFE Target for a Next-Generation Automobile Window

Preparation of Water-Repellent Film on a Plastic Plate by Unbalanced Radio-Frequency Magnetron Plasma Sputtering Using PTFE Target for a Next-Generation Automobile Window

Electric Window Regulator Based on Intelligent Control

In order to effectively solve the problem of installation cost of automobile electric windows and the safety of passengers, the window regulator of the car must have an intelligent control function. For example, most automobile windows now have an anti-pinch function. In this paper, the model of DC brushed motor is analyzed, an intelligent control scheme for automotive power windows is proposed, and the relationship between current ripple and window travel, motor current and external resistance are verified. In the hardware design, S9S12G128 is the main control chip, and the motor current acquisition method is designed. In the software design, intelligent control methods such as current integration method, adaptive and self-learning algorithm and intelligent speed regulation method are proposed to realize functions such as automatic window opening and closing, intelligent anti-pinch and intelligent speed regulation. After many experiments, the results prove the feasibility of the above methods and the stability of the system.

Multi-stable cholesteric liquid crystal windows with four optical states

ABSTRACT An electrically switchable multi-stable liquid crystal device is demonstrated based on a non-uniform cholesteric liquid crystal (CLC) structure in a single cell. The non-uniform CLC structure consists of a polymer stabilised CLC layer and a non-polymer stabilised CLC layer. By taking advantage of the difference in driving electric field strength of the two layers, the device can be switched electrically to four different states: the reflecting state, the reflecting and scattering co-existing state, the scattering-only state and the transparent state. The optical properties of the four states and the transition conditions between the states were elucidated. Moreover, all states with reflecting and/or scattering properties are stable for an extended period of time after switching off the electric field. Thanks to its multi-stability, this device can be used for energy-saving smart windows of automobiles, buildings and in architectural aesthetics. An electrically switchable multi-stable liquid crystal device is demonstrated based on a non-uniform cholesteric liquid crystal (CLC) structure in a single cell. The device can be switched electrically to four different states. All states with reflecting and/or scattering properties are stable for an extended period of time after switching off the electric field. Thanks to its multi-stability, this device can be used for energy-saving smart windows of automobiles, buildings and in architectural aesthetics.

Photonic Multilayer Structure Induced High Near-Infrared (NIR) Blockage as Energy-Saving Window.

Energy-saving window that selectively blocks near-infrared (NIR) is a promising technology to save energy consumption. However, it is hard to achieve both high transmittance in visible light and high reflectance in NIR for the energy-saving windows. Here, a TiO2 /Ag/TiO2 /SiO2 /TiO2 multilayer is demonstrated on a glass substrate to selectively block NIR while maintaining high transmittance to visible light. The thickness of a TiO2 /Ag/TiO2 structure is first design and optimized; the metal layer reflects NIR and the dielectric layers increase transmittance of visible light with zero reflection condition. To further enhance NIR-blocking capability, a TiO2 back reflector is implemented with a SiO2 spacer to TiO2 /Ag/TiO2 structure. The back reflector can induce additional Fresnel reflection without sacrificing transmittance to visible light. The optimal TiO2 (32nm)/Ag (22nm)/TiO2 (30nm)/SiO2 (100nm)/TiO2 (110nm)/glass shows solar energy rejection 89.2% (reflection 86.5%, absorption 2.7%) in NIR, visible transmittance 69.9% and high long-wave (3 ≤ λ≤ 20µm) reflectance >95%. This proposed visible-transparent, near-infrared-reflecting multilayer film can be applied to the windows of buildings and automobiles to reduce the energy consumption.

Photovoltaic-driven transparent heater of ZnO-coated silver nanowire networks for self-functional remote power system

This work reports the first photovoltaic-powered transparent heater and the results suggest their potential for future smart window applications. Transparent heaters are of high interest for application in windows of buildings, automobiles, and aircrafts to ensure clear vision. Here, we propose the photovoltaic-transparent heater system to supply electric power for Joule heating of the transparent heater. The transparent heater is composed of silver nanowire (AgNW) networks to induce heat via the Joule effect. To ensure high stability, a ZnO film is applied as a transparent protection film to the AgNW networks, and it also serves as a thermal conductor for the transparent heater system. The proposed ZnO-coated AgNW transparent heater efficiently uses the Joule effect via the metal nanowire network, resulting in a high operating temperature >300 °C. The ZnO coating is also very effective in maintaining the optical transparency of the heater >67% in the visible spectral range. For on-site application, the ZnO/AgNW transparent heater is powered by photovoltaic cells and drives the heating temperature of 58 °C. The self-powered transparent heaters are therefore considered as suitable for application in transportation, buildings, wearables, and remote heating systems as a smart-window energy system.

Control of water contamination on side window of road vehicles by A-pillar section parameter optimization

The water contamination on the side windows of moving vehicles is a crucial issue in improving the driving safety and the comfort. In this paper, an effective optimization method is proposed to reduce the water contamination on the side windows of automobiles. The accuracy and the efficiency of the numerical simulation are improved by using the lattice Boltzmann method, and the Lagrangian particle tracking method. Optimized parameters are constructed on the basis of the occurrence of the water deposition on a vehicle’s side window. The water contamination area of the side window and the aerodynamic drag are considered simultaneously in the design process; these two factors are used to form the multi- objective optimization function in the genetic algorithm (GA) method. The approximate model, the boundary-seeded domain method, and the GA method are combined in this study to enhance the optimization efficiency. After optimization, the optimal parameters for the A-pillar section are determined by setting the boundary to an area of W = 7.77 mm, L = 1.27 mm and H =11.22 mm. The side window’s soiling area in the optimized model is reduced by 66.93%, and the aerodynamic drag is increased by 0.41% only, as compared with the original model. It is shown that the optimization method can effectively solve the water contamination problem of side windows.

An investigation of automatic flagging methods for aspiration noise in automobiles

If there are small gaps in the seal between a closed automobile door or window and the rest of the car, annoying noises may arise due to airflow through the gaps, or aspiration. While some aspiration noises contain clearly identifiable tones or narrowband components, many aspiration noises do not. As a result, it is often difficult to identify aspiration noise, whether by listening to the recorded sound, or by examining the measured spectrum. Aspiration noise is classified as an error-state, which manufacturers want to remedy before selling the car, so an automatic tool for flagging sounds containing aspiration noise would be helpful. A method for simulating aspiration noise was developed, in which stationary and intermittent components are added to a “base sound” having a spectrum representative of a certain automobile. These simulated sounds were analyzed using trends of single-value metrics and statistics such as Sharpness and estimated kurtosis, and spectral measures such as the power spectral density of time-varying Loudness. The trends observed in these quantities, and their effectiveness as robust aspiration-noise flags, are reported. Future work may include developing a holistic flagging tool for all wind noise error-states, including whistles, cavity noise, and separated flow turbulence noise.