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Sky Like Coating Materials for Hypogeal and SkyScrapers Architectures

Final Report Summary - SKYCOAT (Sky Like Coating Materials for Hypogeal and SkyScrapers Architectures)

Executive Summary:
SkyCoat addresses the emerging needs from architecture and lighting design to go beyond the current solutions in artificial lighting and to recover the integration of men into nature, that is spoilt by the enclosed spaces and by the innatural lighting currently possible in homes, workspaces, and closed areas used in every day life.

It has been in fact proven that the deprivation of natural light generates discomfort, lowers concentration and productivity, affects the mood and has often serious impacts on psychological and even physical conditions.

In parallel urban planning faces two issues: excessive soil usage and environmental impact of the architectures on one hand and increase in the use of underground areas, where natural light is absent. The re-qualification of such areas is of primary relevance and of main interest for market players in building, architecture and real estate. SkyCoat offers a groundbreaking solution to these demands, as it proposes innovative technologies for artificial lighting that are able to exactly reproduce the natural light and the visual perception of the sky and of the sun in any environment both indoors and in outdoors.

The technologies developed by the project constitute a drastic and dramatic shift from current concepts in lighting, where the artificial light is only a surrogate of the natural light produced by the sun and by the atmosphere, which encloses our spaces in a secure closed environment. SkyCoat opens the space through the view of a real sky, a real sun, obtained by means of the combination of two main physical concepts: the diffusing capability of the atmosphere that separates the yellow spectral wavelength of the sun and the bluish spectral wavelengths generated by the sky, recreated by the new SkyCoat materials, and the effect of infinite distance of the sun, recreated by means of an extremely complex combination of optical systems and light sources.

In so doing SkyCoat transfers the concepts for physics, optics and materials sciences into real products - nanostructured materials, projectors and luminaires - and new architectural concepts, that have been successfully demonstrated and documented by means of renders, photos and videos.

The beneficial effects of these technologies have been assessed and measured during the project, through a clinical investigation on 200 healthy persons that experienced the difference between standard artificial lighting and the new lighting produced by the technologies developed by SkyCoat.

Thus SkyCoat not only produces groundbreaking technologies, new concepts in architecture and building refitting and renovation, but has also proven the socioeconomic benefits derived from the application of these technologies. From a technology viewpoint, SkyCoat goes beyond the most advanced lighting, and gives an impact to break current barriers in LED production, and advance the quality of LED light as far as to reach the pure white light from stars.

It advances the know-how in nanomaterials: the project has developed nanoparticles dispersions that can be dispersed in different matrix materials. It advances the applications of optics to the lighting industry, and creates a generation shift from current lighting, where design and creativity generate the added value, to high technological processes and concepts. Having this as a starting point, the technologies developed by the project are expected to become the top level in lighting, difficult to be reached even by major lighting companies, creating a dramatic gap with current market solutions. This ambition has driven the effort of the SkyCoat Consortium and in particular of the idea and IP owner, the SME CoeLux Srl.

Project Context and Objectives:
Architecture has been rapidly moving in the past from traditional housing to skyscrapers, that opened new concepts of urban space usage. Presently urban congestions and increased availability of under-utilized underground spaces pose new challenges to architects, and require new solutions to make such spaces liveable and comfortable to people, thus starting a new trend in architecture and building refurbishing.
These concepts call for a new development that has been limited especially by liveability and psychological constraints given by the absence of natural light: underground architecture, including earth-sheltered, or earth-covered buildings. Hypogeal spaces are one possible direction to start solving urban issues such as congestion, lack of open and public space, and aging infrastructures.
On the other hand, hypogeal architecture suffers limitations from the absence of natural light. Due to the discomfort caused by vision deprivation of the sky and of the sun, hypogeal architecture is currently facing a rapid development only in those regions featured by rather unfavourable climate conditions where the advantages in protection from natural disasters, extreme environmental conditions, difficult living conditions, and stressful climate count more than the before mentioned discomfort.

Similar conditions apply in other "overground" conditions, such as in extreme Northern or Southern Countries, who suffer for many months of sunligth absence, or even large workspaces, that need artificial lighting also during the day. Many studies have reported the impacts of natural light deprivation and of the wide exposure to artificial light on human wellbeing, comfort and even physical and psychological status.

In this context SkyCoat enters with a ground-breaking proposal, aimed at recreating the very experience of the natural light, made of the complementary presence of both direct sun and diffused sky lights, in any space, indoors and outdoors. In so doing, the disadvantages of hypogeal architecture, like limited or no natural light and negative psychological reactions, are blown away by the possibility of reproducing the sun and the sky many meters under the earth surface, therefore opening a new and unexplored market for Real Estate investors, architects, lighting designers and end-users. The project has also investigated the impact of the technology for general lighting, i.e. for home, office, retail, industry, transport contexts, etc. and the the possibility of using SkyCoat in outdoors, e.g. for tailoring the perceived silhouette of skyscrapers or tall building in general.

The goal will be attained by two different approaches, which lead to two groups of products for two different market segments.

The first approach is based on the development of a new, SkyCoat dichroic material, whose dichroic nature comes from its behaviour as a perfect mirror with respect to the long-wavelength component of the impinging light (i.e. the yellowish or “warm-light” component) and as back-scattering diffuser with respect to the short-wavelength one (i.e. the bluish “cold light” component). Notably, the new material will behave in a similar, but not identical, way as the sky does with respect to the sun light, the difference being related to the fact that it operates in reflection, whereas the real sky in transmission mode. In fact, due to the occurrence of the so-called “Rayleigh scattering” process in the atmosphere, the sky transmits the warm component of the direct sunlight and scatters the cold one toward the earth. Indeed, this is the process which determines the variety of the colours of the sky and of the sun light during the hours of the day, the different meteorological conditions, the seasons, etc., and which creates the blue tinges of the shades where the scene is not reached by the direct sun light, but is lit by the diffused sky light.

The second approach is technologically more complex, and thus of higher risk, than the first. However, it leads to higher performances, it can be more easily standardized and therefore has a larger potential impact for indoor applications. This technology, that differently from the previous works in transmission mode, guarantees large perceived sun-to-sky optical distances and parallel sunbeams, with very reduced back stage volumes. The project has developed the first test samples of this "compact" technology comprising complex micro-optical elements, suitably arranged for creating the virtual image of a single, far-distant, sun within physical distances not larger than 20-30 cm. Reaching such high level of compactness requires abandoning the traditional optics, i.e. the one used in standard lighting industry, for joining the field of micro-optics, on which the new industry of compact computer monitors and TV screens has grown in the last decade. The high complexity of this compact technology is fully justified by the foreseen higher compliance to standards and higher optical performances.

To demonstrate the spectacular effects of the developed technologies, demonstrators in real spaces (an apartment, a façade, an open air large scale installation) have been realized and documented by a professional video.

The project has pursued and achieve the following objectives.


The R&D aimed at a substantial innovation at the crossover between different commercial sectors, as it is in SkyCoat, must be performed in tight connection with standardization, in order to ease the products access to the global market. In this respect, the first standard-related objective addressed the following aspects:
• To identify the fields of use of SkyCoat products and become aware about their regulation standards.
• To guarantee SkyCoat product to be compliant to standards for the identified destination of use.
• To guarantee SkyCoat products to be certified according to relevant standards. The certification is relevant not only when it is compulsory but also for certifying the quality in a commonly understood terminology, and thus for enhancing the product recognition. The certification is relevant also for the material “SkySun-Mirrorfoil”: when the material will be integrated by end users into final devices, the component certification will ease the final-product certification by third parties, and consequently the component sales.
• When a SkyCoat product cannot be certified because it results from the integration of two separate components, e.g. a material, an optical and architectural one, to guarantee that all components are independently certified. This will ensure maximum possible recognition of the product quality.

The second standard-related objective concerns the market standard, i.e. the identification for the "compact" product of the ideal set of characteristics which would allow such product to become “the single world standard” for sky-sun illumination. This set comprises non only all the necessary certifications but also general features as performance, size, thickness, overall appearance, consumption rate, maintenance procedure, and, last but not least, price.
The market standard also relates to the level of comfort and users perceived beneficial effects of the new proposed lighting solutions. This aspect has been assessed by a specialized multidisciplinary group of experts appointed at Bartenbach GmbH and by CoeLux Srl and University of Insubria on 200 healthy people and was further confirmed through the demonstration actions and installations.
The identification of this market standard is mandatory in order to prevent customization to prevail over standardization, which will prevent the success of the product on the global-market scale and includes the evaluation of the effects of SkyCoat technologies on wellness and wellbeing and of the assessment of the market requirements.

The third standard-related objective is the establishment of the basis for new standard measurements for what concerns the regulations on the destinations of use and/or the qualification of hypogeal spaces. The project has measured the level of comfort guaranteed by SkyCoat technologies, in the complete absence of real windows, and demonstrated that it is comparable or even better than that guaranteed by standard interior lighting. Seen the results the partner CoeLux Srl intends to apply for a new definition of standards to include the developed lighting technologies, as they behave exactly as windows on real natural light, and should therefore be verified in the same way as windows.


The objective consists in the development, up to the pre industrial level, of a portfolio of new Rayleigh Scattering materials suitable for implementing sky-sun illumination in real-field architectural applications. The objective comprises:
• The development, up to the pre industrial level, of a sub-mm layered material, which reflects the long-wavelength (i.e. the yellowish or “warm-light”) and backscatters the short-wavelength (i.e. the bluish “cold light”) component of the impinging light.
• The development, up to the pre industrial level, of class-1 fire retardant dichroic panels of thickness in the range 1-15 mm, which scatter the short (bluish) wavelength components and transmit the long (yellowish) one in Rayleigh like regime.
• The development of surface treatment processes for increasing the mechanical (i.e. anti-scratch) and optical (i.e. anti-reflection, IR/UV filtering) properties of the dichroic panels of above.
The achievement of these objectives is founded on the realization of custom-made nanomaterials, integrally developed in the frame of the project.


The objective consists in the realization, at the level of functional sample, of four lighting installations and of four luminaires based on the usage of the developed Rayleigh scattering materials. The installations are made of two separate elements: a scattering material and a light projector, capable of shining a flat-intensity, sharp-edge, white-light beam profile just over the reflecting surface (i.e. not outside it). The luminaires, in contrast, are self-consistent modules, where both the reflecting material and the light source are included in a single device. The overall size of the installation is therefore much larger than that of the luminaire.

The objective comprised the realization of the following functional samples, the Technology Readiness Level is also reported for each product:
• Projectors: the "SkyGlimpse" projector (TRL9) - an LED projector delivering a rectangular light beam; the "Blind window" projector (TRL3) - an LED projector with low divergcence delivering a round spot of light, the "Corridor lamp" projector (TRL6) - a linear LED light source used in the Vilnius apartment demonstrator; and the "Stem lamp" projector (TRL4) - a small projector than can be used in floor like types of lamp;
• Luminaires: the "Stem Lamp" (TRL4) - a floor like or bed side kind of lamp; the "Curtain Effect Lamp" (TRL4) - a lamp that recreated the effect of a window covered by a curtain; the "Corridor Lamp" (TRL6) - a recessed lamp than can be well suited for use in corridors and used in the Vilnius apartment demonstrator, and the "Dome" lamp, a small lamp that can be tailored for different uses (TRL2).
• Installations: the "Blind Window" (TRL5), a system that recreates the idea of a window such as the one of ship cabins; the "SkyGlimpse" (TRL4), a lighting system that recreates the idea of a window on the ceiling of a room; the "Façade" (previously Sky at night - TRL6), a covering layer for the beautification of skyscrapers and other old buildings in cities; and the "SkyDome" (TRL6), a large sky installtion for expos, fair and in general outdoors illumination of large areas.

Project Results:
The main S&T results are those indicated in the project objectives:

1) SkyCoat materials with fire retardant and antiscratch properties. These materials are realized on glass and aluminium substrates, using thin layers of nanocomposite coatings custom made during the projec.

2) Custom-made light sources: four projectors with the innovative characteristics needed to reproduce the behaviour and the performance of sun light.

3) Proof-of-concept and real projects for new architectures where the groundbreaking innovation brought by the technologies developed within the SkyCoat project produce the best effects. Of such projects three have been produced for demonstration which have been implemented and can be successfully replicated, one has been produced and verified for an underground metro station and many other have been produced to show the potential of the thechnology.

4) Four luminaires and four installations using the materials and projectors developed during the project.

5) Three demonstrators in 1:1 scale (facade, apartment, and large SkyDome installation) and five additional demonstrators installed at CoeLux Srl showroom in Lomazzo (Italy).

6) A software for the rendering and project execution of new architectures and new lighting systems or lighting designs incorporating the developed technologies and the SkyCoat materials and projectors.

7) The certifications needed for the majority of applications for the SkyCoat technologies and a roadmap for new standards that assimilate this technolgy to real windows opening on the outdoors sky.

8) Two studies demonstrating on a sample of 200 healthy people (50% male, 50% female aged 10-65) that the light generated by the technologies developed by CoeLux Srl, and including those realized thanks to SkyCoat, produce more comfort, generate more wellbeing, reduce stress, enhance attention and productivity and have an overall beneficial effect on mood and physio-psychological conditions as compared to traditional artificial lighting that delivers the same amount of light (in terms of Lux).

9) A consolidated production chain and the relevant commercial agreements for the production and commercialization of SkyCoat products as soon as they are duly IP protected and ready to market.

10) A compact modular technology that is able to generate natural light thorugh a diffusion panel and a background microoptics layer.

Potential Impact:
IMPACT 1. “Novel materials and products where design and the advancement in the properties of the materials are key factor for success”.
The Project contributes significantly to achieve the same aesthetical effect characteristic of the natural light, which we reproduce. The project does not mimck the effect (e.g. as others have been doing, by means of monitor-based devices which project the image of the sky). In contrast, the developed nano-materials reconstruct indoor the same optical process that originates the phenomenon in nature. Up to date, in the field of lighting technology, the concept of “design” relates only to aesthetical characteristics which are added by specialists (i.e. architects/designers) on the top of the technology, without any relevant feedback from the design to the technology level. The situation is opposite in our case: for example, the light changes during different hours or meteorological conditions, i.e. noon or sunset, in clean or stormy sky, imply the reconstruction of different scattering processes; this means suitable control down to the type of nanoparticles (i.e. refractive index, dimension, concentration gradients, etc.) that are used in producing the SkyCoat materials. Therefore, the integration of design and material development is thoroughly applied in our research and our products.

IMPACT 2. “Boosted dynamism of innovation in the field(s) of the creative industry”.
The project has generated a dynamism in innovations by integrating chemical and material sciences, architecture, lighting design, physics, electrical and construction engineering and IT engineering to obtain a completely new concept in architecture. Inside the project, the goal has been attained thanks to the tight cooperation established between: (i) the “creative-industry team” (which comprises architects, light designers, exposition makers and real estate actors from the partners involved) and (ii) the “hard-science team” (i.e. researchers in the field of nano-materials science, chemistry physics and optics from the research institutions and SMEs involved).

IMPACT 3. “Improved communication between actors in the innovation chain also in view of novel consumption patterns”.
The new materials, products and architectural solutions proposed by SkyCoat provide the stake holders in the innovation chain with a number of new approaches for novel consumption patterns along the two main following lines:
1. Due to the need of reducing consumption in artificial illumination, the lighting industry is undertaking a revolutionary development aimed at replacing incandescent and also fluorescent with solid-state technologies (e.g. LED) . However LEDs, nowadays widely used e.g. for light signaling, for displays, in the automotive and for outdoor lighting, still fatigue entering the fairly large home and office markets because of the discomfort that LED light still provides. In fact, their poor performances in terms of color rendering and their perceived “coldness” (due to an excess of blue because of the LED source peak in the emission spectrum) prevent their employment in a wide range of uses where the requirement of providing good color rendering and/or visual comfort are mandatory. In contrast, the integration of these same sources in SkyCoat luminaires and installations turns the limitations of the white LED technology into an advantage: the excess blue light is scattered in the shadows of the scene by the SkyCoat nanodiffuser material, transforming an “unnatural” white LED source into a combination of a yellow, directional light (the “sun”) and of a diffuse blue light (the “sky”), able to recreate the same visual comfort of natural light. This in turn enormously expands the range of applications of white LED sources with a consequent dramatic saving of energy.
2. Due to the need of reducing energy consumption for heating, cooling or humidity conditioning, several countries featured by unfavorable climate conditions are increasing the developing of underground architectural spaces. However, this opportunity is limited by the high discomfort due to the absence of windows, and so of natural light. In this scenario, SkyCoat definitely plays a strategic role since the developed lighting technologies, both in transmission and reflection mode, guarantee a high comfort level for underground living conditions.

IMPACT 4. "Socioeconomic impacts on humans."
As the majority of the world’s population lives and works in increasingly urbanised environments where looking out of their windows often means watching concrete buildings, parking lots and roads, this situation motivates to investigate whether artificial views could provide beneficial effects similar to those of real views to open landscapes. New lighting technologies have been developed in recent years that attempt to remedy this lack of windows with a view to nature. Primarily, technologies from the luminaire- and display-industry have been used for this purpose. Mostly large panels emitting diffuse light with light sources of high colour temperatures (correlated colour temperature of the light source is greater than 6500 Kelvin) try to imitate the blue sky indoors. Sometimes these panels are used to backlight images of natural environments. In most cases, these luminaries vary light intensity and light colour subject to the time of day. Unfortunately the light distribution of daylight is not imitated with these panels and hence these systems are indeed suitable for room lighting purposes but do not generate a realistic impression of a natural daylight opening.
In contrast, the display industry tries to compensate the lack of windows with bright large display arrays. Partially, even real external situations are shown on the display with the aid of outdoor cameras. However, such monitors do not achieve naturalistic brightness levels and light distributions, and consequently create the impression of an artificial window with high technical complexity but are not suitable for room lighting purposes due to low brightness levels.
CoeLux and SkyCoat technologies have been evaluated on 200 volunteers and have proved to produce more comfort and all positive effects on perception, mood, attention and overall on physio-psycological conditions of users. As such the impacts of the technologies are evident not only for daily use in homes or at work, but also for healthcare, where natural light plays an important role on physio-psychological recovery from disease and also in situations where stress is high (e.g. in the gamma blade rooms where cancer radiotherapy is delivered), as well as for diffused diseases such a SAD or discomfort in people living most of their time in light-deprived areas.

IMPACT 5. "Impacts on Europe2020 targets."
SkyCoat has contributed to the target “New skills and jobs” by generating new competences across all the involved actors of the Consortium and – in particular – by creating new skills inside all participating partners. This is evident for involved Research Institutions where new researchers have been involved and already present researchers have increased their competences and skills on innovative materials and research innovations in the areas of applied mathematics, applied physics, optics and materials chemistry. The usage of SkyCoat materials and solutions will also open novel possibilities in design and architecture so creating new skills in the industrial and home design fields as well as in urban and large common use spaces architecture design. Young architects are expected to profit of such opportunities which will generate new jobs in light design and lights production industries and in big design studies, based on the further development of new architectural solutions. SkyCoat results have contributed and will contined to contribute to increase the competitiveness of European Industries, in three ways: (1) through the SkyCoat inventions which will (once the products will become public) put the Consortium participants as first in the market and so in a prominent position vis-à-vis non EU competitors and (2) by increasing skills and know-how, and by paving the way for more innovative products and applications; (3) through the creation of a qualified network of innovative companies (SME and large industries) involved in the industrialization, production, certification, promotion, commercialization and on-site support of the developed technologies, thus spreading innovation and increasing the potential for new skills and new jobs.

IMPACT 6. "Contribution to standards."
SkyCoat has addressed the issue of EU standards adaptation and new standards definition for new and emerging technologies, as addressed by theme NMP.2012.4.0-2 Support for standardization needs. The main impact here concerns the delivery of new standardization documents. This is being possible thanks to one of the Consortium partners who is engaged in the communications with the CEN/CENELEC regarding the adaptation of standards in the field of lighting devices and architecture and construction to the new applications and products resulting from SkyCoat. The Consortium has established contacts with standardization bodies also through the Technical & Scientific Manager.

IMPACT 7. "Contribution to EU2020 strategy for a “green economy”.
SkyCoat products will contribute to Europe 2020 objectives of smart, sustainable and inclusive growth. In fact the developed nanostructured material able to reproduce the natural light conditions in a thickness of few microns is a low VOC (volatile organic compound) coating which can be applied to reusable and to easily recyclable substrates, thus overcoming the environmental issues posed by existing materials (such as the solutions developed in CoeLux which is based only on PMMA thick panels). The value added by the joint and collaborative work of the involved partners is also to achieve the goal to spread awareness and introduce new environmental-friendly technologies in the EU market, and goes beyond national barriers and borders. As such our project is coherent with the Common Strategic Framework for Research and Innovation promoted by the EU through the LIFE Environment program and in line with the Directive 2008/98/EC on waste (Waste Framework Directive) which sets the framework for environmental-friendly business.

IMPACT 8. "Business impacts."
The business impacts for the participating companies and especially for the technology IP owner CoeLux Srl have been evaluated in many million euro in the next 5 years. The fallback on components providers, promoters, distributors and on software provider Next Limit is almost the same size. These impacts benefit the European production network, thus contribute to foster growth. The new developments arising from SkyCoat constitute also a new source of economic impact for the sectors involved in products design and production, from chemistry to optics, from advance LED production to innovative coating techniques, to new architectural designs.

List of Websites:
The project and the underlying concepts are presented in the following websites:

main contacts:
CoeLux Srl
Via Cavour 2
Lomazzo (Italy)
phone: +39 02 36714394