Smart glass or replaceable glass (also smart window or replaceable window in the app) is glass or glass whose property of light transmission is modified when voltage, light or heat is applied. Generally, the glass turns from translucent to transparent, changing from blocking some (or all) wavelengths of light to let light pass through.
Smart glass technology includes electrochromic, photocromic, thermochromic, particle-hanging, micro-blind and crystalline-fluid-dispersed polymers.
When installed in building envelopes, smart glass creates an adaptive climatic building shell, with the ability to save on heating, air conditioning and lighting costs and avoid the cost of installing and maintaining motorized light screens or curtains or blinds. Blackout smart glass blocks 99.4% of ultraviolet rays, reducing fabric fading. For a suspended particulate device (SPD) - a smart glass type, this is achieved along with a low emissivity coating.
Important aspects of smart glass include material costs, installation costs, electricity and durability costs, as well as functional features such as speed control, dimming possibilities, and transparency levels.
Video Smart glass
Electrically replaceable smarts
Suspended particle device
In suspended particle devices (SPDs), thin-film laminated nano-scale particles such as rods are suspended in liquids and placed between two pieces of glass or plastic, or attached to one layer. When no voltage is applied, the suspended particles are arranged randomly, thereby blocking and absorbing light. When a voltage is applied, the particles are suspended parallel and let light pass. Varying the film voltage varies the orientation of the suspended particles, thereby adjusting the glazing color and the amount of light transmitted.
SPD can be manually or automatically "set" to precisely control the amount of light, glare and heat passing through, reducing the need for air conditioning during the summer months and warming up during the winter. Smart glass can be controlled through various media, such as photo sensors and automatic motion detectors, smartphone applications, integration with intelligent buildings and vehicle systems, knobs or light switches.
Intelligent light control technology enhances user control over their environment, providing better user comfort and prosperity and improving energy efficiency. This technology provides more than 99% UV blockage and transfer of status in 1 to 3 seconds. In the car, the light transmission range for this technology is 50-60 times darker than a regular sunroof up to twice as clearer than an ordinary sunroof. Data published by Mercedes-Benz show that SPD technology can reduce the temperature of the cabin inside the vehicle by 18 Â ° F (10 Â ° C), leading to increased passenger comfort and decreased AC load. Other advantages include reducing carbon emissions and eliminating the need for expensive window dressings.
SPD-Smart Glass is patented by the public Frontiers Research company.
Automotive
SPD commercialization is accelerating in the automotive industry for reasons including safety, convenience, fuel economy, and design. The SPD automotive side and rear windows and sunroofs offer many benefits for passengers in the vehicle. Because of fast-switching and the ability to be tuned, they reduce unwanted light and glare, allowing users to retain their view from the outside while reducing glare on displays and video screens, or coloring windows for additional privacy. SPD automotive glass also minimizes the buildup of heat in the vehicle because of their ability to block the sun's heat. Many SPD window systems automatically switch to maximum blocking status when the vehicle is not in use.
Aircraft
By 2016 about thirty aircraft models have SPD windows.
Marine
Adaptation and control are essential in the marine environment. SPD allows users to instantly and precisely control the amount of light, glare and heat passing through windows, skylights, portholes, partitions and doors.
Architecture
Product Architecture SPD - windows, skylights, doors and partitions - available as laminated panels or insulated glass units for new construction, replacement and retrofit projects. These products offer a unique blend of energy efficiency, user comfort, and security. Product architecture made with SPD technology:
- Remove curtains and shades
- Keep day and night views
- Allow people to enjoy on-demand shading
- Minimize glare
- Reduce heating and cooling needs
- Maximize natural lighting
- Protect the furniture and interior artwork from waning
Electrochromic devices
The electrochromic device changes the nature of light transmission in response to voltage and thus allows control over the amount of light and heat passing. In the electrochromic window, the electrochromic material changes its opacity: it changes between transparent and colored states. A burst of electricity is required to change its opacity, but once the change is made, no electricity is required to maintain the particular color that has been achieved.
First generation electrochromic technology tends to have a yellow cast in their clear and blue country in their colored countries. Dark occurs from the edge, moving inward, and is a slow process, ranging from many seconds to several minutes (20-30 minutes) depending on the size of the window. Newer electrochromic technology, also known as "smart dye glass," overcomes previous versions of deficiencies by removing yellow cast in clear circumstances and irradiating more neutral gray colors, coloring evenly from the outside inwards, and accelerating tinting speeds up to less than three minutes, regardless of the size of the glass. However, this newer electrochromic technology has not passed the ASTM-2141 for reliability and long-term durability testing. The lack of third party independent ASTM certification is one aspect that limits market acceptance compared to first generation electrochemical technology that has successfully passed the ASTM-2141 certification.
Electrochromic glass provides visibility even in the dark and thus maintains visible contact with the external environment. It has been used in small scale applications such as rearview mirrors. Electrochromic technology also finds use in indoor applications, for example, to protect objects beneath the museum's glass showcase and glass frame images from the damaging effects of UV and artificial light wavelengths. Electrochromic glass can be programmed to automatically color in accordance with weather or sun position or user preferences. It can also be controlled via mobile apps and even through popular voice assistants.
The latest advances in electrochemical materials associated with electrochemical transition cycles have led to the development of reflective hydride, which became reflective of absorption, and thus changing the state between transparent and mirrored.
Recent advances in modified porous nano-crystal films have enabled the creation of electrochromic displays. The structure of a single substrate display consists of several stacked porous layers which are printed on top of one another on a substrate modified by a transparent conductor (such as ITO or PEDOT: PSS). Each printed layer has a specific set of functions. The working electrode consists of a positive porous semiconductor (say Titanium Dioxide, TiO
2 ) with adsorbed chromogens (different chromogens for different colors). This chromogen changes color by reduction or oxidation. Passivator is used as a negative of the image to improve electrical performance. The insulator layer serves to increase the contrast ratio and separate the electrode work electrically from the counter electrode. The counter electrode provides a high capacitance to compensate for the load inserted/extracted on the SEG electrode (and maintains the overall charge neutrality of the device). Carbon is an example of a charger film. The carbon conductor layer is usually used as a conductive feedback contact for the counter electrode. In the final molding step, the porous monolithic structure is overprinted with liquid or gel-polymer electrodes, dried, and then can be incorporated into various encapsulation or enclosures, depending on the application requirements. The displays are very thin, typically 30 micrometers, or about 1/3 of a human hair. The device can be activated by applying an electric potential to a transparent conductive substrate relative to the conductive carbon layer. This causes a reduction in the molologic viologen (color) occurring within the working electrode. By reversing the applied potential or providing a disposal path, the device will whiten. The unique feature of electrochromic monoliths is the relatively low voltage (about 1 Volt) required to dye or whiten viologens. This can be explained by the small over-potential required to induce electrochemical reduction from the adsorbed surface of viologens/chromogens.
Polymer dispersed liquid crystal device
In a dispersed liquid crystal device (PDLC), the liquid crystals are dissolved or dispersed into a liquid polymer followed by compaction or polymer preservation. As the polymer changes from liquid to solid, the liquid crystals become incompatible with the solid polymer and form droplets throughout the solid polymer. The curing conditions affect the droplet size which in turn affects the final operating properties of the "smart window". Typically, a mixture of liquid polymers and liquid crystals are placed between two layers of glass or plastic covering a thin layer of transparent material, conductive followed by polymer preservation, thus forming the basic sandwich structure of the smart window. This structure is basically a capacitor.
Electrodes from the power supply are attached to the transparent electrode. Without a given voltage, liquid crystals are randomly arranged in droplets, resulting in scattering of light as it passes through smart window assemblies. This results in a transparent appearance, "milky white". When a voltage is applied to the electrode, an electric field formed between two transparent electrodes on the glass causes the liquid crystal to align, allowing light to pass through the droplets with very little scattering and resulting in a transparent state. The level of transparency can be controlled by the applied voltage. This is possible because at lower voltages, only a few liquid crystals align fully in the electric field, so that only a small part of the light passes while most of the light is scattered. As the voltage increases, fewer liquid crystals remain parallel, so the resulting light becomes less. It is also possible to control the amount of light and passing heat, when special tints and inner layers are used. It is also possible to create Fire-rated and anti-X-Ray versions for use in special applications. Most devices currently offered operate only in or outside the country, although technology to provide variable transparency levels is easy to implement. This technology has been used in interior and exterior settings for privacy controls (eg conference room, intensive care room, bathroom/shower door) and as a temporary projection screen. It's commercially available in rolls as an adhesive-supported smart film that can be applied to existing windows and trimmed to size in the field.
Micro-curtain
Micro-blinds - currently being developed at the National Research Council (Canada) - control the amount of light passing in response to the applied stress. The micro-blind consists of a thin metal curtain that is rolled on the glass. They are very small and practically invisible to the eye. The metallic layer is deposited by magnetron sputtering and patterned by a laser or lithography process. The glass substrate includes a thin layer of conductive oxide layer (TCO) transparent. Thin insulators are stored between the rolled metal layer and the TCO layer for electrical disconnection. Without a given voltage, the micro-curtain is rolled up and let the light pass through it. When there is a potential difference between the rolled metal layer and the transparent conductive layer, the electric field formed between the two electrodes causes the micro-curtain to be rolled to stretch and thus block out the light. Micro curtains have several advantages, including switching speed (milliseconds), UV durability, customized appearance and transmission. Theoretically, the curtain is simple and cost-effective to make. Videos available on YouTube briefly describe the micro curtain.
Nanocrystal
Thin layers of nanocrystals embedded in glass can provide selective control over both visible light and heat-near-infrared (NIR) light independently of climate. This technology uses a small electric shock to replace the material between NIR-transmitting and NIR-blocking states. Nanocrystal indium tin oxide is embedded in a glass matrix of niobium oxide forming a composite material. Voltage ranges over 2.5 volts. The same window can also be switched to dark mode, blocking light and heat, or into transparent full-blown mode. The effect depends on the synergistic interactions in the region where the glass matrix meets the nanocrystal which increases the electrochromic effect. Atoms are connected through a nano-glass interface, causing structural rearrangement in a glass matrix. Interaction creates space inside the glass, allowing the moving charge to be easier.
Maps Smart glass
Non-electric smart glass
Mechanical intelligent window
Vistamatic
The lower cost alternative for smart glass is Vistamatic Vision Panels, a privacy glass consisting of three sheets of glass sealed as single panels with flat spacing, alternating lines to allow for privacy or observation. Adapted to the needs of the facility, this non-electric privacy glass panel is operated manually while still providing a blurry look similar to the electrical appliance.
Sunvalve
The low cost alternative to high tech smart windows consists of two retoreflective panels that are retrofitted to the back with narrow slits in between. When a liquid with the same refractive index as that of a panel is pumped into a cavity between them, the glass becomes transparent. When the liquid is pumped out, the glass turns into a reflective retro again. Examples of such windows are the Norwegian brand Sunvalve.
It was discovered by a professor at the University of Delaware, see US patent 8635817.
Smartershade
Another cheap alternative to smart electronics is Smartershade. This glass consists of two polarized glass panels with a patterned optical axis allowing it to transition smoothly between gray shadows to near complete blackout opacities. The advantage is a much higher light extinction (blackout) than EC or SPD glass at a much lower cost. The drawback is that it requires two panels, one of which must be able to move, and that on the most transparent it only recognizes 50% of incident light. This glass can also be produced as a clear mirror, or smartmirror.
Tech related areas
The smart glass expression can be interpreted in a broader sense to include also glass that changes the nature of light transmission in response to environmental signals such as light or temperature.
- Different types of glass can exhibit a variety of chromic phenomena, that is, based on photochemical effects of glass change the nature of light transmission in response to environmental signals such as light (photochromism), temperature (thermochromism), or voltage (electrochromism). Liquid crystal, when in a thermotropic state, can change the nature of light transmission in response to temperature.
- Recent advances in electrochromic materials have led to the discovery that electrochromic metal hydride transitions create a reflective face and not an absorbent face. These materials have the same idea, but go about the problem in a different way by switching between transparent states when they go to a reflective state when voltage is applied. The switchable mirror was originally developed by Ronald Griessen at the Vrije Universiteit in Amsterdam. They use rare earth metals and create mirrors that can be replaced with metal-hydride. The low release coating rejects unwanted thermal heat because of the sun's infrared. These mirrors have become common places in the car's rearview mirror to block the following vehicle spotlights. Electrochromic colors that absorb optically reduce the intensity of the reflection. These mirrors must be fully converted to a reflective state as a muted reflection must withstand darkness. Initially metals, they are converted into transparent hydrides by injecting hydrogen in a gas or liquid phase. Then switch to a reflective state.
- Various metals have been investigated. A thin Mg-Ni film has a low-reflective and visible transmittance. When they are exposed to H 2 gas or reduced by alkaline electrolytes, they become transparent. This transition is associated with the formation of magnesium nickel hydride, Mg 2 NiH 4 . Films are created by cosputtering from separate targets of Ni and Mg to facilitate variations in the composition. One target d.c. magnetron sputtering can be used eventually which will be relatively simple compared to the deposition of the electrochromic oxide, making them more affordable. Lawrence Berkeley National Laboratory stipulates that new transition metals are cheaper and less reactive, but contain the same quality, thereby reducing costs.
- The Tungsten-doped Vanadium dioxide VO 2 layer reflects infrared light as temperatures rise by more than 29 degrees Celsius, to block the transmission of sunlight through windows at high ambient temperatures.
This type of glaze can not be controlled manually. In contrast, all electrically powered smart windows can be created to automatically adjust their light transmission properties in response to temperature or brightness with integration with thermometers or light sensors.
The smart window topic in a further sense includes embedded LED movies that can be activated at reduced light intensity. The process of laminating embedded LED films between glass will enable the production of embedded LED-embedded glasses. Since most glass companies are unskilled in installing LEDs on metallized glass, LEDs are placed on a separate transparent conductive polymeric interlayer that can be laminated by glass laminate units.
- Production technology
Smart glass is produced by laminating two or more glass or polycarbonate sheets.
Usage examples
Smart glass using one of these technologies has been seen in a number of high profile applications. Large-scale installations are completed at the Guinness Storehouse in Dublin, where more than 800,000 people per year can see the smart glass used in interactive displays and privacy windows. Smart glass is used to launch Nissan Micra CC in London using a four-sided glass box consisting of 150 consecutive substitutable glass panels to create a striking outward appearance. The main use for smart glass is in internal partitions and walls, adding a level of privacy and multifunctional distance for the company to enjoy the ability to switch screens and doors from clear to personal.
Smart glass has found utility in the health care industry, where easy-to-clean surfaces are important and there are patient privacy considerations. Smart glass products can replace traditional blind systems that are difficult to clean and can store dirt and insects. Studies have shown that patient comfort can help reduce recovery time.
One of the most popular smart glass applications is the projection screen.
Another example of use is the installation of PDLC-based smart glass, at The EDGE , a glass cube protruding from the 88th floor skydeck from the world's tallest residential tower, Eureka Towers, located in Melbourne.. Cube can accommodate 13 people. When it extends out of the building by 3 meters, the glass is made transparent, giving the view of Melbourne cube dwellers from a height of 275 meters. The same type of smart glass has also been proposed for use in hospitals to be controlled to provide patients with the necessary privacy.
PDLC technology is used in view to introduce the Nissan GTR at the Canadian International Auto Show in Toronto.
Electro-chromatic glass is used on the Cadillac Voyage 1988 body concept that adjusts the sun's load on the car and can darken it.
In the media, the updated sets for Sunrise's Sunrise program display a Smart Glass background that uses liquid-convertible glass. The new device with Smart Glass allows street scenes to be seen occasionally, or replaced with opaque or transparent blue coloration, covering the view.
Bloomberg Television currently features a bright glass background in his studio in New York, Hong Kong and London.
The Boeing 787 Dreamliner has an electrochromic window that replaces the pull-down windows on the existing plane. NASA is looking to use electrochromics to manage the thermal environment experienced by the newly developed Orion and Altair space vehicles.
Smart glass has been used in some small production cars. The Ferrari 575 M Superamerica has an electrochromic roof as standard, and Maybach has a PDLC roof as an option. Some Glass Privacy has been applied in Maybach 62 cars for privacy protection purposes.
The Hong Kong office uses a 130 square meter privacy glass, available in sizes up to 1,500 × 3,200 mm.
The ICE 3 high speed train uses an electrochromatic glass panel between the passenger compartment and the driver's cab.
The elevator at the Washington Monument uses a smart glass so passengers can see the memorial stone inside the monument.
The city's toilets in the Museumplein square of Amsterdam have a smart glass to facilitate the determination of the occupancy status of an empty stall when the door is closed, and then for privacy when it is occupied.
Source of the article : Wikipedia
0 Comments