Description of technology

The technology used by Octoglass to produce "smart glass" is so-called organic polymeric electrochrome, which is based on the redox reactions of organic molecules under the influence of voltage of electric current.

Why are we using this particular technology?

1. It allows to achieve excellent consumer characteristics both in color and contrast as well as in state switching speed. In addition, the use of organic polymer electrochrome technology makes it possible to produce products with almost no haze.

2. The presence of a black tint of tinting, the most demanded by the consumer.

The presence of other shades of tint that can be implemented as desired by consumers, such as blue, green, orange, etc.

4. Ability to flexibly change the lower and upper limits of light transmission within a single delta of changing contrast.

Actual technologies of "smart glass" presented on the market

There are only a few product groups on the market with smart glass technology that allow you to change the transparency. Among them are the best known commercially available technologies such as PDLC (Polymer Disperced Liquid Crystals) and SPD (Suspended Particle Device).

PDLC is a technology that allows you to change the haze of glass and is usually supplied as a white milk film for subsequent lamination into glass. When high alternating voltage is applied, the film becomes transparent. If the voltage decreases, the film becomes blurred. When no voltage is applied at all, the film becomes completely opaque - white-white or blurry. At this point PDLC technology provides maximum privacy, you can not see something through the "off" PDLC film. But, light transmission remains at the same level as in the transparent state.

Unlike our electrochromic solutions, PDLC technology uses high voltages up to 110 volts AC, which can be dangerous for applications in environments such as automotive, waterborne transport or interior architectural solutions. PDLC technology is used in limited cases to ensure privacy in rooms by means of installed translucent structures such as partitions, doors and the like.

Another technology that is currently widely available on the market is a technology called SPD. This technology has been developing for several decades, and allows to change the light transmission characteristic of glass from dark blue to relatively transparent with a neutral color. In its essence, SPD-technology is a nano blinds, which are opened under the influence of electromagnetic field from AC, thereby increasing light transmission. Without voltage supply, the nano blinds are closed under the influence of thermal movement of polymer matrix molecules. The disadvantages of this technology include the fact that even in the most transparent state in translucent structures, the maximum light transmission does not exceed 60%. Accordingly, SPD-technology cannot be applied where requirements on the minimum light transmission are established, for example, on motor transport means. Another disadvantage of SPD, which is the key for many consumers, is the high haze coefficient of glass regardless of its state of light transmission. As it is necessary to note one more disadvantage of SPD - absolutely high cost. The cost of a square meter of glass using SPD technology can reach two to three thousand USD. And if we talk about a solution for cars or glass for other types of vehicles, the cost increases many times. Some square meters, as a rule, are estimated by manufacturers and distributors at ten and more thousand dollars.

Glass with SPD or PDLC technologies without voltage supply provide maximum darkening/opaque and energy supply is required to make them transparent.

In addition to PDLC and SPD, so-called thermochromic solutions can be found on the market in very small volumes. They also belong to the category of "smart glazing", in which a reaction very close to electrochromic occurs. Under the influence of temperature or ultraviolet radiation, the glass is either coloured or brightened. In other words, the light transmission characteristic changes. The most striking example of this technology can be called photochrome glasses, as well as with dioptres, and with sunglasses. Photo chrome glasses change the characteristic of light transmission depending on how much ordinary light or ultraviolet hits the glass. In Europe, among other things, there are also developments in the field of liquid crystal glass based on liquid twister crystals. Already there are the first exhibition instances, but the prime cost of this kind of production is very high. In the environment of inhabitants, usually, under the electrotonic tuning the technologies connected with SPD, or with PDLC are understood. Despite the fact that in very rare cases on the market there can be found proposals for electrochromic solutions, it should be noted that our development is completely unique and protected by copyright in many countries. We have conducted thousands of experiments, implemented a theoretical base and built comprehensive models of our electrochromic systems. We now have the opportunity to conduct computer simulations of our electrochromic devices before releasing them for full tests. Application of the simulation significantly saves time developing new qualities and properties, and, in principle, is done in order to get, from a consumer point of view, the ideal product. Yes, there are "smart glass" technologies on the market, but our products are unique. And without remorse, we are the world leaders in the development of electrochromic systems!

Product Description

The end product, electrochromic glass Octoglass, is a triplex directly made of glass but using an electrochromic polymer. The glass used for triplex has a conductive substrate on its inner surface that is completely invisible to the eye. The glass is connected to the contacts from a specialized controller, which allows to control the light transmission of the electrochromic glass itself if the user wishes. Electrochromism here means that under the influence of voltage of an electric current there is an electrochemical reaction within which the glass is either tinted (coloured) or lightened.

One of the key characteristics of Octoglass EC-glass is the ability to reach the upper limit of light transmission of more than 70%, which is especially important when using electrochrome glass on vehicles, where the lower legal limit of light transmission of glass is set at 70% level. However, for special applications, e.g. as a light camouflage device, the upper limit can be lowered to achieve zero light transmittance in a darkened state.

Another advantage of electrochromic glazing is that there is no additional haze when using electrochromic polymers. Normal car glass has a haze level of 4%-6%. The finished electrochromic glass has the same haze level. Opalescence, as a negative factor due to increased haze, can cause significant discomfort when using glass with high haze level under constantly changing lighting conditions such as driving. Electrochromic glass does not have this disadvantage.

The black tint of the tint color provides not only visual comfort, but also prevents dangerous color shifts. Under unfavorable conditions, color shift due to the use of glass that is not colored in neutral black may cause an accident or other unpleasant consequences due to misunderstanding of the environment by a person.

Cycle time

One of the main parameters of any "smart glass" that can dynamically change one of its characteristics, such as light transmission, is the time taken to completely change this state. Much depends on the technology used and the expected durability of the device. PDLC technology switches from state to state almost instantly, even for a large format, time is less than a second. When voltage is applied, the glass with PDLC switches instantly. This is partly due to the fact that the glass itself switches continuously during operation. If you have an AC frequency of 50 Hz to power the glass, you should expect the glass itself to turn on and off quickly 50 times per second. PDLC glass will appear transparent visually, but human fatigue when working behind or near a PDLC glass is much higher than without PDLC design.

SPD technology works a little slower. The switching rate of glass from SPD technology is heavily influenced by the ambient temperature. Without voltage, the glass with SPD is as tinted as possible. With a voltage of 100-110 volts, it becomes brightened. The enlightenment process is relatively fast; for a half-square-metre glass format, about a few tens of seconds is sufficient and the glass becomes as transparent as possible. In the opposite direction, namely for dimming, the process is a little slower and it is highly dependent on temperature. Usually it takes about 1 to 3 minutes for half a square metre glass to become completely blacked out at room temperature. At temperatures below 15 degrees Celsius, this process slows down even more. And at critical temperatures, around -40 degrees Celsius, the glass is darkened within 15 minutes and brightened in about 2-3 minutes.

For electrochromic systems, the speed of painting or discolouring depends directly on the design of the device itself and, directly, the materials and coatings used inside the device. There are ways to increase the speed, but in most cases this acceleration has a very negative impact on the longevity of the device. So, for example, at correctly picked up algorithms of management of electrochromic glass, it can sustain tens and hundreds thousand cycles of switching. But if you use different methods of accelerating the processes of coloring and brightening, especially if you do not go into details or just do not know the whole mechanics of electrochromic glass, the risk is very high to reduce the life of the electrochromic device in several thousand times.

Octoglass is very cautious about methods of accelerating painting and lightening, as the company aims primarily to ensure the longevity of the device. We expect our products to delight our customers for many years to come.

Progress does not stand still and thanks to the latest developments in Octoglass, results have already been obtained that allow for rapid coloration and lightening of electrochromic glass. As of the beginning of 2020, we have developed solutions to achieve phenomenal switching speeds without sacrificing durability. Half a square metre of electrochromic glass can be painted in a minute and a half, and clarification takes only a minute. For most consumers, a similar switching speed is more than enough.

Specialists and ordinary people constantly point out that "smart glass" is breaking through more and more to the mass market. If 10 years ago, "smart glass" was only making timid steps, appearing in expensive cars, but in luxury apartments, today electrochrome solutions are available to a much larger range of consumers and who knows, maybe in a few years, the usual glass will remain out of business and it will successfully replace the glass "smart".

That in the future

Organic polymer electrochrome is best suited for use in vehicles. With the polymer technology it is not difficult to create curved glass or fancy shaped glass. The polymer can replicate any shape and any surface. However, according to Octoglass, inorganic electrochrome technology is best suited for architectural applications, especially for facade use. Our engineers and chemists have developed such technology (hybrid inorganic electrochrome), as well as accelerated development of specific devices based on a complete solid-state inorganic electrochrome solution. These variants of electrochrome technology are aimed at solutions related to the glazing of large areas, facades of buildings and structures.