The Meaning of Multifunctionality
Smart coatings are considered multifunctional if they provide complex functionality in a single environment. An example here would be a glass coating that enables both photovoltaics capability and self-dimming capabilities. This kind of multifunctionality might be provided through a multilayer coating of some kind.
Another kind of coating that might be considered both smart and multifunctional is a coating that can offer several different functionalities, but not always at the same time. It has been shown for instance polyphenol coatings can be deployed as antimicrobials and anti-inflammatories for medical implants, but also to tune the optical properties of metallic nanoparticles for both medical diagnostics and therapeutic purposes.
The literature usually suggests that multifunctional smart materials are coatings, but n-tech thinks that this in part reflects the state of the technology. In theory – and increasingly in practice — multifunctional smart surfaces can be created not just with coatings but also (1) by deeply embedding sensors in the surface or (2) patterning the surface in a manner that provides it with a modicum of multifunctional intelligence.
State of the Multifunctional Art
n-tech believes that this mix of options for adding smart multifunctional capabilities to surfaces will lead to substantial new business revenues in the next few years. In fact, we are already seeing smart multifunctional surfaces at or near the point of commercialization:
In the construction industry we have now reached the point where it is possible to fabricate smart windows that combine self-dimming, solar energy generation and self-healing into a single IGU. This could be achieved through a multilayer coating approach with the main challenge being making sure that one layer did not interfere with another.
In aerospace, some smart surfaces can monitor the structural health of wings and fuselage and then make modest repairs automatically. One part of this combo is very well developed – smart structures for structural health monitoring. Self-healing materials are also well advanced, although not necessarily yet in the aerospace context. It should not, however, be too involved to combine functionalities as long the expected automatic repairs are not too demanding.
In medicine, the development of coatings with antimicrobial and anti-inflammatory properties is of obvious importance. And here, as we mentioned at the beginning of this Chapter, a group of researchers has already created a multifunctional coating on bioactive agents, which addresses both these issues together.
And as n-tech sees it, three factors are driving the market for multifunctional coatings and surfaces and each create their own opportunities. These are (1) the “smartness meme,” (2) the need to constantly create new value for suppliers fighting commoditization, (3) the possibility that the multifunctional coating and surface creation business will result in processes will confer competiveness in smart materials and beyond.
Multifunctional Surfaces and the Smartness Meme
The multifunctional coatings opportunity is being shaped by the growing marketplace insistence that buildings, transportation, devices for providing healthcare and even complete cities be “smart.” This is what we mean by the “smartness meme.”
Often in this context it is not completely clear what is meant by “smart.” However, the sense of it is that a material is smart if it is highly functional in a dynamic and responsive manner; a self-cleaning surface is “smart” because it can clean and does so in response to a buildup of dirt.
Given this, coatings and surfaces that are smart in multiple ways would seem to fit better into the evolving need for “smarts” than garden varieties, of smart coatings. And, in some cases, multifunctional smart coatings and surfaces may improve functionality, while at the same time improving aesthetics.
Messaging smart: From the perspective of multifunctional coatings and surfaces, this “smartness meme” opens up marketing possibilities for makers of multifunctional coatings. At the messaging level, “multifunctional” can be branded as the smartest of smart materials creating a marketing fit with many “smart” products that are emerging across markets in developed nations. In other words – “smart is in and what we are offering is especially smart.”
Desperately seeking multifunctional: Conversely, in the current bullish environment for “smart everything,” OEMs will be desperately seeking ways to make their products smarter. A number of options are available to them, notably embedded sensors, nano-patterned surfaces and smart coatings. All three of these approaches can be made to present as multifunctional. However, of course, the functions that are being combined must also match the specific needs of the application.
Multifunctional Surfaces and the War Against Commoditization
Firms in the coatings, component and substrate spaces constantly face a war against commoditization and smart materials/smart surfaces present the core of an anti-commoditization strategy. Multifunctional smart materials may be regarded as the apex of that strategy. The offer suppliers — both large, established firms and start-ups – to create significant market value, while differentiating themselves in the market place.
As n-tech sees things, multifunctional surfaces can potential improve price/performance products in applications across many areas. For example, the self-dimming window that was also a solar panel that we mentioned at the beginning of this chapter might be much less costly than buying a window plus shades plus a solar panel, especially once the multifunctional surface technology had matured a bit.
In fact if total costs are taken into consideration, n-tech believes that multifunctional surfaces can achieve attractive price/performance points quite quickly in the automotive, aerospace, healthcare and medicine, and construction industries. And more than improved economics is involved here – the creation of multifunctional surfaces implies a high level of innovation at the intermediate level, which could be quickly transferred to the final products themselves.
Fabrication of Multifunctional Surfaces: Opportunities and Implications
There is already a plethora of fabrication approaches to creating multifunctional coatings and surfaces. However, none of them are completely satisfactory with the problems occurring at both the tactical and strategic level.
One tactical issue is that some of multifunctional coatings/surfacing technologies are not yet capable of covering the large areas required (say) by the walls of a building. At the strategic level, a leading factor constraining the deployment of multifunctional surfaces of various kinds is the apparent lack of cost effective ways to actually create such surfaces.
Examples of the kind of problems that emerge here include finding ways that multilayer functional coatings, for example, can be applied so that lower layers are not impeded in their functionality. Another important questions is how can nano-engineering be deployed to provide multifunctional intelligence through surface patterning and in a manner that points towards commercialization.
These are mostly R&D questions at the present time, but also ones that could potentially lead to real opportunities if satisfactory and appropriate technologies can be found. As usual some remarkable things can be done in the lab, but it is typically hard to scale this work up to production level quantities. So it is as well not to treat “breakthroughs” in the fabrication of multifunctional coatings too seriously until they can be proved to be scalable. And we should also note that it is not just coating and patterning technologies that are in a state of flux, but also multifunctional coatings synthesis, which appears to be at an especially very early stage of development.
This gloomy state of affairs is alleviated, however, by the fact that success in creating better fabrication and synthesis addressing the need for multifunctional surfaces may have revenue generation potential beyond multifunctionals.
Specifically, we think that multifunctionals – because of their demanding requirements — will be a good test for new manufacturing approaches of a variety of kinds. For example, approaches that work well with multifunctional smart coatings and surfaces may work excellently with unifunctional coatings and surfaces. So a firm that develops novel manufacturing approaches for the multifunctional smart surfaces sector can expand them to many other markets.