The Symbiotic Relationship Between Sustainable Design and Nanotechnology By Lidia Berger, LEED AP and David Gibney, LEED AP
This is a great time to be in the construction industry. Business is booming. Construction cranes divide the horizon in each direction. Architects, interior designers, engineers, contractors – all are scrambling to keep up with the demand for new buildings. What is interesting about the current building boom is that it is virtually global in terms of both location and building typology. Computer chip fabrication plants in Singapore, shopping malls in New Delhi, high-end condominiums in Moscow, five star hotels in Dubai – all over the globe buildings are emerging from the ground.
But regardless of type or location, construction today is increasingly complex. Unprecedented cost escalations for copper, steel and concrete have made it difficult for contractors to meet building budgets. Compound that with rising energy costs and water shortages and it’s clear to see why building owners are seeking to make highperformance, sustainable buildings – projects that use less energy and water, provide superior benefits to occupants, and also reduce negative environmental impacts. Our firm, HDR Architecture Inc., has long specialized in designing sustainable advanced technology facilities. Whether for industry, applied research or academic support, we find that our client’s laboratories are increasingly more diverse in the research they support. Today’s research lab must accommodate multiple sciences and be able to quickly adapt for new research. To furthermore support these new research fields today’s laboratories must also be able to control indoor environmental conditions (air cleanliness, temperature, vibration) with unprecedented precision. From the lab designer’s perspective the most demanding of these research facilities is the curious, everexpanding field of nanotechnology. Nanotechnology will have dramatic, exciting impacts on future generations. When our nanoscience research clients describe the purpose of these facilities it is awesome in the true sense of the word. It leads us as lab designers to ask: how will nanotechnology affect buildings in the future? And from our sustainability perspective we ask: will nanotechnology help make buildings truly sustainable? Conversely, will sustainable design principles enhance nanotechnology research in the future?
Learning from the microcosm – Nanotechnology deals with physical interactions at the molecular level. The word “nano” refers to “billion”, thus a nanometer is one billionth of a meter, very small indeed. Understanding what makes nanotechnology special requires one to recall the lessons learned from high school physics courses – and then to forget many of them. For example, we have all been taught that gravitational forces exist between two masses. When released, objects on Earth drop to the ground because the force of the Earth’s gravity acting on that object is overwhelmingly more powerful than the object’s gravitational pull on the Earth itself. But at the nanoscale the effects of gravity between two nano-size building blocks, regardless of particle size, is virtually negligent. However, the affect of electromagnetic forces between nano particles is much, much stronger and differs from how we experience electricity at the human scale. Another difference between the nanoscale world and ours is the relationship of density and strength. Most applied nanotechnology is comprised of working with complex “nanotubes” of single wall carbon molecules called Fullerenes. Fullerenes can be stretched and deformed without breaking. Proportionally, they have little density and therefore are very, very low mass objects. In other words, they are disproportionately strong in comparison to their light weight. In fact, single wall nanotubes weigh only one sixth as much as steel yet they are often over 100 times stronger. Working with these building blocks allows scientist to re-assemble molecular structures in unprecedented ways. It is precisely these phenomena that create the endless possibilities of nanotechnology, which include, as a few samples, the following:
• Cancer treatment that safely eradicates specific cancer cells without damaging adjacent body tissue, all without pain. • Electronic communication that is infinitely faster with less material. • Self-cleaning surface materials • Fabrics that breathe, are very lightweight, shed moisture completely, and are much stronger than fabrics previously known. Today nanotechnology is more of a research and development field than an applied industrial technology. All indicators suggest that this will change quickly. In fact, the National Nanotechnology Initiative (http://www. nano.gov/) predicts that by the year 2020 nanotechnology will be a global industry worth over $1 trillion USD each year. To get there takes research money, and the funds are there: • In 2005 the global investment in nanotechnology research was $4.8 billion USD. • In 2007 the U.S. Federal government approved a $4.6 billion annual budget for its National Nanotechnology Initiative. • According to the UK Royal Society, the European Union will spend approximately ₤1 billion on nanotechnology research in 2007. Nanoscience is a unique science in that it is comprised of multiple diverse science disciplines. Unlike applied sciences, which normally evolve from singular established sciences, nanoscience integrates multiple, diverse science disciplines such as organic and inorganic chemistry, physical chemistry, molecular biological sciences, and quantum physics. To create useful nanoscale applications from these different fields requires an integrated team approach. Sustainable design operates precisely the same way.
Sustainable design – Also known as “green” building, sustainable design is a focused, concerted process to create high performance buildings that are healthy for occupants, and which reduce negative impacts to the environment. Sustainable design has become more than a trend in the past decade. Building owners and occupants realize that green buildings cost less to operate and are more pleasant to dwell in. In many cases they also cost less to build. How is sustainable design different from traditional design? Most notably sustainable design is the result of true design team integration. Rather than a linear process where a building is designed in steps by professionals isolated from each other, sustainable design pulls all design team members together at the beginning of the process. This includes the owner and occupants, and preferably the contractor as well. Sustainable design is information driven. While it does require more design time at the beginning of the process, the benefits of this collective effort are many. Sustainable design is a big subject, and to keep some sense of a working order to it, sustainable design champions tend to follow an “outward to inward” approach normally based on five categories :
Sustainable Site Design – How we integrate buildings into sites has a profound impact on the impacts to the environment as well as how well the building will be able to perform in terms of heating and cooling, lighting, materials used, and water required. Much can be done to reduce energy, water and building materials with thoughtful holistic approaches to site design.
• Nanocrete™ – One example of how a nanotechnology product can enhance a building design is Nanocrete . Very, very thin cellulose fibers are the key to this new concrete product. (A square inch contains more than one billion cellulose fibers.) When these fibers are mixed with concrete the result is a durable building material lighter than standard concrete, with superior workability, improved hydration, and significantly reduced cracking. This will reduce environmental impacts from less mining for aggregate and cement, and from avoiding the energy generation required to replace damaged concrete in the future.
Water Conservation and Protection – Buildings use a great deal of potable water and yet much of these water volumes can be easily reduced without negative impacts to building performance or occupant comfort. Potable water is becoming increasingly scarce in many parts of the world and our urban and suburban development patterns are contributing to much of the contamination of these sources. Sustainable design reduces water consumption inside and outside of buildings. It also protects natural water bodies by harvesting and treating graywater and/or storm water to re-use for appropriate secondary purposes, such as sewage conveyance or irrigation.
• Aerogel Water Purification – Argonne National Laboratory researchers have developed a technique for creating porous semiconducting aerogels that is highly effective at removing targeted impurities from water. By altering the chemical and physical characteristics of the aerogel the researchers are able to manipulate its pore size. Accordingly, the aerogel can be custom fabricated to absorb specific pollutants. Scientists believe this same aerogel process could be used to purify hydrogen or in large scale environmental remediation, such as cleaning up an oil spill.
Energy Conservation & Renewable Energy – Most buildings use much more energy than is needed to meet the demands for normal human comfort and associated activities. By integrating a comprehensive approach to building design many building mechanical systems can be dramatically reduced in size and likewise power demand. In addition, lighting systems can be easily designed to use less energy by using higher efficiency lamps/ bulbs, and installing a lighting control system. Finally, passive strategies such as daylighting and solar access can also dramatically reduce power consumption while simultaneously enhancing the experience of dwelling in a building. Nanotechnology will have a meaningful impact on how we generate and transmit power. But of greater significance, nanotechnology holds a bright promise to dramatically reduce energy demand first.
• Nano wires – Another intriguing feature of carbon tubes is that the show great promise at conducting electricity without gaining heat, meaning no loss of current. This has profound implications for electrical distribution at the utility grid scale, and how power might be distributed through a building or even a computer. At this time researches are racing to develop carbon tube “nano wires” – the ultimate wire that will transmit electricity without signal loss and subsequent heat gain.
• Quantum dots lighting – Researchers at Sandia National Laboratories in Albuquerque, New Mexico (USA) have created a new means to produce artificial light using quantum dots (nanoparticles). By manipulating the surfaces of the quantum dots they emit light when exposed to near ultraviolet light emitter diodes. According to Sandia the quantum dots “strongly absorb light in the near UV range and re-emit visible light that has its color determined by both their size and surface chemistry.” Sustainable Building Materials – Which materials are used to construct a building will affect the total amount of energy that is embodied in the final structure. In addition, harvesting raw materials to make buildings, such as aggregate for concrete or lumber for wood products, normally has a negative impact on the environment. Such strategies as using recycled content construction materials, using locally harvested raw materials or adapting and reusing existing buildings can reduce these negative environmental impacts. Plus, they are often the most cost effective solutions as well.
• Nano “Velcro” – Researchers at Michigan State University have created a material that sticks together using molecular “hooks” like Velcro® (but without “loops”). The material is self-repairing, heat-resistant and has reportedly over ten times the bond of conventional epoxy resins. This will allow scientists to attach microscopic materials firmly together, whether computer chips or surgical implants, without the use of adhesives. For the construction industry thus could be used for securing laminates to substrates, encapsulation, or binding materials that previously were not easily adhered to one another.
• Nano cement – Each year between 2 to 2.5 billion tons of cement is produced to meet the demands for the construction industry. Making cement (the gray powder binding agent of concrete) takes a tremendous amount of energy and it is estimated that producing it alone constitutes between 5-10% of all greenhouse gases. Researchers at Massachusetts Institute of Technology and LaFarge Cement, the largest international manufacturer of cement, have discovered that cement can be replaced with other substances whose nanoparticle structure resembles cement. At the current time magnesium oxide is proving to be a sound replacement. In fact, commercial producers like Austrailia’s TeoEco’s have produced Eco-cement, which besides reducing embodied energy and greenhouse gas emissions, also absorbs CO2 once cast.
Indoor Environmental Quality – Buildings are created for people, yet too often little attention is paid to how our buildings impact us. Because most people will spend 90% or more of their lives indoors how we construct these interior spaces is very important. By creating interiors that are safe, healthy and adaptable, interior architects can profoundly impact employee productivity, student learning, and overall occupant satisfaction. To achieve this requires close scrutiny of indoor air cleanliness, noise, lighting, temperature and humidity and other human comfort factors.
Nano paints and coatings – Even paint is becoming a nanoscience product! Paints and coatings can receive multiple benefits by infusing them with nanoparticles: better adhesion, reduced drying time, greater durability, greater insulation value and even resistance to absorption of air-borne contaminants.
Nano fabric treatments– One of the very first commercial applications of nanotechnology was for fabric treatment, in particular, for stain resistance and water proofing. Nano- fabric treatment typically works by densely embedding nanoscale fibers into the surface of the material that is treated. These “hairs” cause enough surface tension so that water beads cannot break down into smaller droplets and soak into the fabric. Nano-fabric treatment has several advantages, including permanence, no discoloration or odor, and it is completely free of Volatile Organic Compounds (VOCs) and other toxins. Building construction and nanotechnology – The study of nanotechnology is a materials science that is unusually cross disciplinary. Virtually every field of science is rushing to discover what opportunities nanotechnology can offer. Building sciences, primarily specialized materials sciences, are likewise participating. But how quickly is the construction industry embracing nanotechnology? Not too fast, at least not yet. The construction industry has been less aggressive than other fields. According to a 2005 PloS Medicine article titled “Nanotechnology and the Developing World ” the Construction Industry is in 8th place for embracing nanotechnology as follows: 1. Energy storage, production and conversion 2. Agricultural productivity enhancement 3. Water treatment and remediation 4. Disease diagnosis and screening 5. Drug delivery systems 6. Food processing and storage 7. Air pollution and remediation 8. Construction 9. Health monitoring 10. Vector and pest detection and control There are likely several reasons for this: (1) using “unproven” technology is considered to be not only risky but often irresponsible, (2) designers and contractors also tend to use products they are familiar with because it’s easier, (3) the relative amount of true nanotechnologyrelated building products at this time is still small, and(4) emerging technologies are always more expensive when they are new to the commercial market.
What nanotechnology-enhanced building products are in use currently? According to the Freedonia Nanotechnology in Construction U.S. Industry Study, of the $100 million dollars of nanomaterials expected to be used in U.S. construction by 2011, at least 73% is expected to be for Coatings while 12% is likely to be used for Composite materials. The remainder of the balance is for other applications.
Does sustainable design enhance nanotechnology? So, nanotechnology is clearly going to play an active role in how we sustainably build in the future. But if we look at sustainable design and nanoscience facilities today, is there a connection? In fact incorporating sustainable design strategies in the design, construction and operation (all three are critical) is essential to the successful implementation of any nanoscience research facility. The Birck Center for Nanotechnology at Purdue University is a great example of how sustainable features actually enhance the science of nanotechnology. It is interesting to note that something as simple as landscaping maintenance must be given full consideration. For example, mowing a lawn creates vibration from the gas engine, which is detrimental to nanoscale research. (When a researcher is “pushing atoms around” having the table shake at any level is unacceptable.) So, within 40’ of the Birck Center building footprint perimeter there is only low/no maintenance vegetation and in particular no turf. In addition the Birck Center for Nanotechnology building maintenance policy is to avoid fertilizers and pesticides to minimize chemical contamination in the building. Typically these contaminates can be transferred very easily inside the building by the occupants. For this same reason salt is avoided for de-icing sidewalks during winter. Other ways to minimize building contamination is through the use of walk-off mats and foot cleaning systems as well as setting a policy of no smoking within 30’ of the building (minimum). In fact at the Birck Center for Nanotechnology smokers are required to take a drink of water before entering any cleanroom so as to remove any outstanding particulates from becoming airborne. Another nanotechnology facility that benefits from sustainable design is the Center for Integrated Nanotechnologies (CINT) at Sandia National Laboratories in Albuquerque, New Mexico. By specifying interior finishes that are low or zero VOCs the researchers benefit from cleaner air. In addition the researchers benefit from daylighting and from superior air quality (exemplary temperature, humidity, and air contaminant control). By installing low-flow and low-flush plumbing fixtures the building’s overall potable water consumption is reduced by over 30%. By planting indigenous vegetation and using “smart” irrigation controls the total irrigation water demand is reduced by more than 50%. And by following an integrated team design process the building’s mechanical systems were designed to reduce energy consumption by 30%, thus saving CINT over $100,000 each year in energy costs! Not only are these sustainable features good for the environment but by saving the owner money these features conserve fiscal resources, which can then be used for further research. “Sustainability” also includes sustaining the building Owners & Occupants.
Outlook for the future – sustainable design and nanotechnology are both poised for rapid growth and development. Both will have significant impacts on our global society, hopefully bringing greater prosperity to more people and in turn helping to reduce, perhaps even repair negative environmental impacts. Who knows? As sustainability and nanotechnology become further associated there is no way to know how they will complement each other. For now, it is sufficient to recognize that architects and engineers must become conversant and comfortable with nanotechnology. Nanotechnology is the way of the future. Those who understand how it enhances sustainability will be able to harness its immense potential, creating cost effective buildings that are superior in performance, offer healthy interiors, and are better for the environment.