Smart Windows Research Articles

Educational effectiveness of remote training with smart glasses for impression-taking.

To compare the educational outcomes of remote instruction (RI) in impression-taking using smart glasses with those of face-to-face instruction (FI) and paper-based self-learning (SL) and analyze the educational effects, aiming to develop a remote clinical training strategy. Participants were recruited from among the dental residents who were trained in the first-year clinical program at the university hospital in 2023. The participants were divided into three groups as the original skill level was equal, and the groups were assigned RI, FI, printed guidance, and SL. All the participants took impressions of the jaw models attached to the mannequin using alginate impression material. Next, assigned instructions were provided. Then again, the trainees took impressions of the jaw models. The pre- and postinstruction impressions of each participant were evaluated, and the change in the impression score was statistically analyzed. The pre- and postinstruction scores of the trainees in the RI and FI groups showed a significant increase (p<0.05), whereas no significant difference was observed in the score changes in the SL group. In the intergroup comparisons, the score changes of the RI and FI groups were greater than those of the SL group, although no significant difference was found between the score changes of the RI and FI groups (p<0.05). RI in impression-taking using smart glasses has a greater educational effectiveness than paper-based SL. It has also been suggested that RI can have educational efficacy similar to FI.

Enhancing cyclist safety in cyclist-vehicle interactions through early hazard notifications: a comparison of bi-modal cues at head level

Cyclists frequently face numerous hazards on the road. Often those hazards are posed by motorised vehicles. Advanced support systems that alert cyclists to potential dangers could enhance their safety. However, research in this area, particularly regarding hazard notifications for cyclists, remains sparse. This work assesses bi-modal early hazard notification concepts (combining visual cues with either auditory or tactile feedback) provided at head level (smart glasses with speakers, tactile headband). They are detailing the nature of the hazard, its direction relative to the cyclist, and the timing of exposure. This work investigates cyclists' preference and perception of the proposed concepts for two hazardous situations originating from interactions with vehicles: ‘dooring’, the hazard of a potential collision with an opening door of a parked vehicle (evaluated through a test track study, N = 32) and ‘being overtaken’ which poses the hazard of being cut off or hit by the overtaking vehicle (assessed in a bicycle simulator study, N = 21). The study involved comparisons of supported and unsupported rides, focusing on their impact on usability, intuitiveness, workload, and perceived safety. Our findings reveal varied preferences for the supporting feedback modality, with 56% favouring visual-auditory and 31% visual-tactile. The participants rated user experience, intuitiveness and perceived safety for the use of both concepts quite high. Further, the workload for assisted rides was rated as equally low as for unassisted rides.

A highly visible-transparent thermochromic smart window with broadband infrared modulation for all-season energy savings

Abstract Thermochromic smart windows effectively reduce the energy consumption for building through passive light modulation including the transmission of visible (TVis), near-infrared (TNIR), and the emissivity of mid-infrared (εMIR) in response to the ambient temperature change. However, thermochromic windows that maintain high TVis while modulating TNIR and εMIR simultaneously are highly desirable but still challenging. Here, we develop a thermochromic smart window based on a two-way shape memory polymer to enable reversible transformation and achieve TNIR modulation of 44.0% and εMIR modulation of 76.5% while maintaining high TVis (&amp;gt;50%). Compared to traditional windows based on silica glass, this device shows 4°C lower temperature in summer daytime, 2°C higher in winter daytime, and 1°C higher in spring nighttime. It is expected that our device can achieve greater annual energy savings in comparison with commercial glass anywhere in the world and promote the progress of thermochromic windows for energy-efficient buildings.

A Pilot Randomized Controlled Study to Determine the Effect of Real-Time Videos With Smart Glass on the Performance of the Cardiopulmonary Resuscitation.

The aim of this study was to determine the effect of real-time videos with smart glasses on the performance of cardiopulmonary resuscitation performed by nursing students. In this randomized controlled pilot study, the students were randomly assigned to the smart glass group (n = 12) or control group (n = 8). Each student's cardiopulmonary resuscitation performance was evaluated by determining sequential steps in the American Heart Association algorithm they applied and the accuracy and time of each step. A higher number of participants correctly checked response breathing, requested a defibrillator, activated the emergency response team, and provided appropriate chest compressions and breaths in the smart glass group than the control group. There were significant differences between groups. Furthermore, more participants significantly corrected chest compression rate and depth and hand location, used a defibrillator, and sustained cardiopulmonary resuscitation until the emergency response team arrived in the smart glass group than in the control group. Additionally, a significantly shorter time was observed in the smart glass group than in the control group in all variables except time to activate the emergency response team (P < .05). Remote expert assistance with smart glass technology during cardiopulmonary resuscitation is promising. Smart glass led to a significantly better ABC (airway, breathing, circulation) approach, chest compression depth and rate, and hand position. Furthermore, remote expert assistance with smart glass has the potential to improve overall resuscitation performance because it enabled students to initiate resuscitation, use a defibrillator, and defibrillate patients earlier. Nurses may benefit from smart glass technology in real life to provide effective cardiopulmonary resuscitation.

Organic Ligand‐Free Scalable Dual‐Band Electrochromic Smart Windows

AbstractDual‐band electrochromic (DBEC) smart windows are an emerging energy‐saving technology, especially those constructed from single‐component DBEC materials as they offer an easy way to independently regulate visible (VIS) and near‐infrared (NIR) light. However, the current complicated organic ligand approach used to synthesize single‐component DBEC materials necessitates a post‐annealing treatment, which may severely compromise the scalability of DBEC smart windows. Herein, one organic ligand‐free process is developed to produce well‐controlled Nb‐doped anatase TiO2 nanocrystals (NTO NCs) followed by spraying on arbitrary substrates, giving NTO rigid or flexible films with good DBEC properties and a high optical modulation over 92%. A prototype of a 20 cm × 20 cm DBEC smart window is built. The simplicity and scalability of the synthesis and fabrication process make it a scalable approach to constructing large‐area electrochromic smart windows and foils, with promising applications in fields such as buildings and automobiles.

Electrically Controlled Smart Window for Seasonally Adaptive Thermal Management in Buildings.

Smart windows offer a sustainable solution for energy-efficient buildings by adapting to various weather conditions. However, the challenge lies in achieving precise control over specific sunlight bands to effectively respond to complex weather changes and individual needs. Herein, a novel electrochromic smart window fabricated by integrating a self-assembled cellulose nanocrystals (CNCs) layer with an electrochromic poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS) layer is reported, which exhibits high near-infrared transmittance, low solar reflectivity (26%), and infrared emissivity (20%) in winter, and low near-infrared transmittance, high solar reflectivity (91%), and infrared emissivity (≈94%) in summer. Interestingly, the material offers dynamic temperature control based on its photothermal properties, maintaining the internal temperature of buildings within a comfortable range of 20-25 °C from morning to night, particularly in winter with significant daily temperature fluctuations. Simulations show that the CNC-PED device demonstrates excellent energy-saving and CO2 emission reduction capacities across various global climate zones. This study presents a feasible pathway for constructing season-adaptive smart windows, making them suitable for energy-efficient buildings.

Multifunctional shape-memory smart window based on femtosecond-laser-printed photothermal microwalls

Abstract Smart windows (SWs) garner significant potential in green buildings owing to their capability of on-demand tuning the solar gains. Apart from solar regulation, people always desire a type of slippery SW which can repel the surface hydrous contaminants for anti-fouling application. Unfortunately, the up-to-date slippery SWs that respond to electrical/thermal stimuli have drawbacks of inferior durability and high energy-consumption, which greatly constrain their practical usability. This article presents our current work on an ultra-robust and energy-efficient near-infrared-responsive smart window (NIR-SW) which can regulate the optical transmittance and droplet’s adhesion in synergy. Significantly, laser-printing strategy enables us to seed the shape-memory photothermal microwalls on a transparent substrate, which can promote daylighting while maintaining privacy by near-infrared (NIR) switching between being transparent and opaque. As a light manipulator, it turns transparent with NIR-activated erect microwalls like an open louver; however, it turns opaque with the pressure-fixed bent microwalls akin to a closed louver. Simultaneously, the droplets can easily slip on the surface of erect microwalls similar to a classical lotus effect; by contrast, the droplets will tightly pin on the surface of bent microwalls analogous to the prevalent rose effect. Owing to shape-memory effect, this optical/wettability regulation is thus reversible and reconfigurable in response to thealternate NIR/pressure trigger. Moreover, NIR-SW unfolds a superior longevity despite suffering from the raindrop’s impacting more than 10 000 cycles. Remarkably, such a new-type SW is competent for thermal management, anti-icing system, peep-proof screen, and programmable optics. This work renders impetus for the researchers striving for self-cleaning intelligent windows, energy-efficient greenhouse, and so forth.

A Facile Electrochemical Strategy for Achieving a High-Conductivity Polypyrrole Derivative with Intrinsic Metallic Transport as a High-Performance Electrochromic Conducting Polymer Film.

Conjugated polymer electrochromic materials (PECMs) with tailored optical and electrical properties are applied in smart windows, electronic displays, and adaptive camouflage. The limitation in the electrical conductivity results in slow and monotonous color switching. We present a polypyrrole film incorporated with a toluene-p-sulfonic group (PPy-TSO-F), via a one-step electrodeposition technique. The PPy-TSO-F thin film (110 nm) achieves an impressive electrical conductivity of 1011 S cm-1, a high carrier mobility of 82 cm2 V-1 s-1, and intrinsic metallic electronic behavior. It demonstrates exceptionally reversible multicolor switching, transitioning from emerald green (-1.5 V), to bluish green (-1.4 V), bright yellow (-1.2 V), greenish yellow (-0.6 V), reddish brown (0.1 V), dark brown (0.3 V), and atrovirens (0.6 V). The fast charge transport and high carrier mobility render the film with an ultrafast electrochromic switching speed of 0.01 s/0.02 s. This research provides a new route to designing ultrafast multicolor switching PECMs with metallic charge transport.

Experimental Evaluation Study of the Comfort and Energy Performance of Suspended Particle Device Smart Windows in a Residential Building: Achieving Optimal Control during the Cooling Season

In contrast to traditional windows, smart windows dynamically affect indoor visual and thermal environments through Visible light transmittance (VT) and Solar heat gain coefficient (SHGC) changes. Therefore, for enhancing smart window application effects, it is necessary to analyze comprehensively the impacts of smart window tinting on indoor visual and thermal environments, and to establish appropriate tinting control methods. This study aimed to determine optimal smart window control strategies for residential buildings during the cooling season by evaluating visual and thermal comfort and energy performance in an actual building equipped with SPD smart windows. An experimental building was located in Sejong, South Korea (36.5°N latitude, 127.3°E longitude; temperate climate zone), and the measurements were conducted from July to August 2023 to compare glare, indoor daylight illuminance, thermal comfort, and cooling and lighting energy between typical and smart windows. And, optimal control methods were proposed from general comfort and energy performance perspectives. The measurements indicated that it was difficult to satisfy all aspects of the visual and thermal environment, and comprehensively it was recommended to employing “always tinting” on summer. However, on a clear day, jointly applying smart windows and lighting dimming control and controlling automatically based on indoor daylight illuminance levels were found to be the most effective as it not only secured visual comfort performance but also reduced lighting energy consumption.

Surface-induced nano-generator utilizing a thermo-responsive smart window based on ionic liquid aqueous solution that exhibits lower critical solution temperature type phase separation

We demonstrate a surface-induced nano-generator utilizing a thermo-responsive smart window based on ionic liquid aqueous solution that exhibits lower critical solution temperature (LCST) type phase separation. This smart window was fabricated by filling an aqueous solution of [nBu4P][CF3COO] between the glass substrates coated with two different polymers: a polyimide with an alkyl side chain and an amorphous fluoropolymer. Below the LCST, the transmittance of the smart window was 87 %, nearly identical to that of a glass substrate. In contrast, when heated above the LCST, the [nBu4P][CF3COO] aqueous solution undergoes phase separation, causing the [nBu4P] cations and [CF3COO] anions to adsorb onto the polyimide with the alkyl side chain and the amorphous fluoropolymer facilitated by the surface pinning effect. This adsorption process results in the smart window generating electricity while transitioning to an opaque state. Therefore, the proposed smart window functions as an electricity-generating thermo-responsive device that can switch between transparent and opaque states in response to temperature changes.

Acceleration Photochromic Performance in Tungsten Oxide

Tungsten oxide (WO3) photochromic films require external force to accelerate the return to their original state after being photoinduced to color under ultraviolet light; otherwise, the fading process is exceedingly slow. The research explores the effects of various metal ion dopants on WO3 photochromic performance, with a focus on Fe doping. Fe-WO3 composite films demonstrate rapid coloration (3 minutes) and bleaching (30 minutes) processes, significantly improving upon undoped WO3. The mechanism of Fe ion catalysis in electron transfer is elucidated through HRTEM, SEM, EDS, and XPS analyses. The practical application of Fe-WO3 composite films in smart windows is evaluated using Energy-plus software, showing substantial energy savings across diverse climate zones. Our findings render great opportunities for innovative photochromic designs that can help achieve energy-saving performance in windows.

Low-voltage and high-contrast polymer dispersed liquid crystals enabled by ferroelectric fluoro-copolymer doped polyimide film

Smart windows incorporating polymer dispersed liquid crystal (PDLC) technology provide user-friendly operation and play a significant role in intelligent buildings and building energy conservation. Long standing issues of the PDLCs such as high driving voltage, low contrast ratio, and narrow viewing angle hinder their applications. Here PDLCs are sandwiched between the hybrid substrates composed of the ferroelectric polyvinylidene fluoride trifluoroethylene (P(VDF-TrFE)) copolymer and the homogeneous polyimide. The high dielectric constant and ion-trapping ability of ferroelectric copolymers increase the effective voltage drop in the PDLCs. Concurrently, the local electric field created by large dipole moment of ferroelectric copolymers triggers the alignment of liquid crystals (LCs) along the applied field. These synergistic effects contribute to a substantial decrease in the driving voltage of PDLCs. In the opaque state, the random dipole moments in ferroelectric copolymers disrupt the LC orientations near hybrid substrates, thereby increasing the light scattering and reducing the transmission of PDLCs. Consequently, the proposed PDLCs exhibit a contrast ratio ∼2× higher compared to the conventional PDLCs at normal incident. Moreover, the proposed PDLCs demonstrate a wider viewing angle in the transparent state compared to conventional PDLCs. This development promises energy-efficient, eco-friendly, and cost-effective smart windows.

Dynamic optical and thermal modulation of electrochromic smart windows and sunglasses based on benzothiadiazole-extended viologen derivatives

Dynamic optical and thermal modulation of electrochromic smart windows and sunglasses based on benzothiadiazole-extended viologen derivatives

A convenient method to fabricate sputtered thermochromic VO2 nanoparticles by SiO2 microspheres for smart windows

A convenient method to fabricate sputtered thermochromic VO2 nanoparticles by SiO2 microspheres for smart windows

Synthesis and Advanced Applications of Transition Metal Oxides

Transition metal oxide semiconductor materials have gained significant attention in recent years because of their unique electrical, magnetic, and optical features. Transition metal oxides (TMOs) with partially filled d-shells have a wide range of characteristics and play important roles in a variety of technological applications. They are influenced by stoichiometry changes, which alter their physical, chemical, and electrical properties. Controlled synthesis, doping, and post-synthesis treatments can all have an impact on the size, shape, crystal structure, and overall attributes of TMOs. These changes affect applications such as magnetic materials and smart windows. Effective techniques include valence state control, dopants, alloying, structure engineering, nano and defect structuring, and surface modification. This article discusses the synthesis methods, crystal structures, electrical properties, and applications of transition metal oxides, as well as their involvement in cutting-edge technologies such as electronics, optoelectronics, energy storage, and catalysis.

Looking through the crystal ball feasibility of tele-echocardiography using smart glasses in neonates: a pilot study.

In recent years, the importance of telemedicine has increased significantly. Especially in the field of echocardiography, virtual reality glasses offer the possibility of real-time data transmission without restrictions in the examination process. In particular, the care of critically ill newborns with suspected CHD might be improved by allowing a specialized paediatric cardiologist to remotely guide an echocardiographic examination. The current study aims to prove whether novices, under Google Glass guidance by a paediatric cardiologist, can perform an appropriate neonatal echocardiography. The current study is a prospective monocentric single-blinded pilot study. Participants were supposed to perform two test runs: The first test run was "unguided" and the second test run was instructed via Google Glass. A validated training simulator for neonatal echocardiography "EchocomNeo, Echocom GmbH" was used. The study took place at the Leipzig Heart Center, Department of Pediatric Cardiology from April 2022 to November 2022. A total of 21 medical students were enrolled. In total 252 views (126 views in each test run) were recorded. The overall performance was significantly higher in the Google Glass guided test run compared to "unguided" (structure score: 77.6% vs. 63.2%. p < 0.001 and quality score: 58.7% vs. 47.2%, p < 0.001). Also, the time was significantly lower in the Google Glass guided test run than in the unguided test run, p = 0.014. Google Glass guidance by a paediatric cardiologist could optimize the performance of novices in echocardiography using a standardized neonatal echo-simulator with structural normal cardiac anatomy.

Optimization of electrochromic Mo doping WO3 films: A study on dual-phase stacked structures for energy-efficient smart windows

Amorphous tungsten trioxide (a-WO3) films were prepared on ITO conductive glass via electrodeposition and subsequently crystallized to obtain crystalline WO3 (c-WO3) films by heating a-WO3. A dual-phase stacked WO3 film was fabricated by covering Mo-a-WO3 film onto c-WO3/ITO substrate using electrodeposition and thermal-assisted electrodeposition methods, respectively. Optimization of electrochromic performance was achieved by varying Mo doping levels (0∼5 atom%). Results demonstrate that appropriate Mo doping (3 atom%) enhances the electrochromic properties of a-WO3 films. Mo doping introduced structural distortions that reduced energy barriers and enhanced ion mobility, leading to improved electrochemical and electrochromic properties. The intermediate c-WO3 layer improves adhesion between a-WO3 top film and ITO glass substrate, while the porous structure of a-WO3 layer increases the number of active sites for electrochromic reactions. Mo3-a-WO3/c-WO3 dual-phase stacked film with doping 3 atom% Mo shows an optical modulation range of 83.4 % at 633 nm, a coloration efficiency of 74.3 cm2/C, rapid response time (bleaching/coloration: 3.4 s/6.1 s), and 86.6 % retention of its maximum current density after 2000 cycles, respectively. The high oxidation ion diffusion coefficient (3.53 × 10−10 cm2/s) and reduction diffusion coefficient (1.55 × 10−10 cm2/s) were also observed. This dual-phase stacked film shows significant improvements in electrochromic performance due to the synergistic effects between the dual phases and Mo-doping. Electrochromic device (ECD) assembled with Mo3-a-WO3/c-WO3 dual-phase films as the working electrode, ITO glass as the counter electrode, and 1 mol/L LiClO4/PC solution as the electrolyte exhibited an optical modulation range of 74.2 % and response time (bleaching/ coloring) of 6.8 s/3.7 s. These findings confirm that ECD with Mo-a-WO3/c-WO3 dual-phase films offer excellent electrochromic performance.

A Multimode Dynamic Color-Changing Device for Smart Windows Based on Integrating Thermochromic and Electrochromic Properties.

Electro- and thermochromic materials have been greatly applied in smart windows and displays due to the excellent properties of color variation and solar radiation. However, the mono color and single response to voltage and temperature hinder their application and development. Here, a multimode dynamic color-changing device (T/ECD) was developed by integrating the electrochromic property of synthetic viologen dyes and the thermochromic properties of hydroxypropyl acrylate (HPA). The T/ECD achieves four modes of optical regulation, namely, colorless transparent state, tinted transparent state, colorless opaque state, and tinted opaque state, which can be regulated independently/coordinately using heat and voltage. The optimized T/ECD switched color at 1.2 V with 15 s or adjusted the transparent/opaque state at >34 °C with 46 s. In addition, based on the red viologen (ViO-R), green viologen (ViO-G), and blue viologen (ViO-B) dyes, colorful T/ECDs were successfully designed and fabricated, and T/ECDs have excellent cycling properties, expanding the application requirement. Moreover, we demonstrated their application in smart windows and privacy protection. The design philosophy and successful exploration have great prospects for energy-saving buildings, displays, and information masking/storage systems.

Optimization of Contact Pad Design for Silver Nanowire-Based Transparent Heater to Improve Heating Characteristics.

Transparent heaters are gaining significant attention for applications such as antifog glass, smart windows, and smart farm greenhouses. A transparent heater basically consists of transparent conducting materials that serve as a heating area and contact pad electrode to apply power. To fabricate a transparent heater, materials with excellent light transmittance and low sheet resistance are required. Among various transparent conducting materials, such as Indium Tin Oxide (ITO), carbon nanotube (CNT), graphene, and silver nanowires (AgNWs), AgNWs are particularly favored due to their good electrical, optical, and mechanical properties. However, in order to improve the heating characteristics of transparent heaters, research is essential not only on improving the properties of transparent conducting materials but also on the design of contact pad electrodes that can uniformly improve current distribution. Here, we explore various shapes of contact pad electrodes for AgNW-based transparent heaters to improve current distribution. Shapes such as line, spot, twisted, and parallel-type contact pad electrodes are designed and investigated to optimize overall heating characteristics. We analyze the heating properties of these transparent heaters with various contact pad electrodes, demonstrating how their specific shape and size affect heating characteristics and uniformity. We also investigate the optimal shape of the contact pad electrode to minimize transmission loss through UV-VIS spectroscopy. As a result, we confirm that the shape of the contact pad electrode was important for simultaneously achieving high heating characteristics of 120 °C, good heating uniformity, and over 80% transparency in an AgNW-based transparent heater.

Flexible Near-Infrared Plasmon-Polaritons in Epitaxial Scandium Nitride Enabled by van der Waals Heteroepitaxy.

Van der Waals heteroepitaxy refers to the growth of strain- and misfit-dislocation-free epitaxial films on layered substrates or vice versa. Such heteroepitaxial technique can be utilized in developing flexible near-infrared transition metal nitride plasmonic materials to broaden their photonic and bioplasmonic applications, such as antifogging, smart windows, and bioimaging. Here, we show the first conclusive experimental demonstration of the van der Waals heteroepitaxy-enabled flexible semiconducting scandium nitride (ScN) thin films exhibiting near-infrared, low-loss epsilon-near-zero, and surface plasmon-polariton resonances. Deposited on fluorophlogopite-mica substrates with molecular beam epitaxy, polaritonic ScN heterostructures mark the first semiconducting nitride to exhibit plasmon resonance at the 1100-1250 nm spectral range, inside the biological transmission window. Interestingly, optical properties of such ScN exhibit remarkable stability even after bending more than 100 times. Creating low-cost and high-quality flexible yet refractory plasmonic ScN heterostructures for the near-infrared spectral range will advance flexible optics and bioplasmonic devices for practical applications.