by Richard McPartland
The building blocks of tomorrow are being thought about in the classrooms and innovation labs of today. A whole new generation of construction material innovations are set to shape the buildings we use for work, rest and play in the years to come. Here we take a sneaky peek at 10 innovations with amazing potential to change the world we live in.
The material innovations shaping the built environment of the future
1. Glorious graphene - Scaling up production of the 'wonder material'
Fascination with this ultrathin, ultra strong material (pictured) stems from its remarkable physical properties and the potential applications these properties offer for the future. Graphene could revolutionize a variety of engineering and scientific fields due to its unique properties, which include a tensile strength 200 times stronger than steel and an electrical mobility that is two to three orders of magnitude better than silicon.
Until 2004, scientists knew one atom thick, two-dimensional crystal graphene existed, but no-one had worked out how to extract it from graphite. Enter Professor Andre Geim and Professor Kostya Novoselov, working at the University of Manchester, who finally managed to extract the substance. Today, realizing the full potential of graphite is occupying the minds of many researchers - including scientist David Boyd at Caltech who has come up with a way of mass-producing the material much more quickly while ensuring the resulting sheets are smoother and stronger than those produced using regular thermal processes.
Potential applications in architecture include small-scale products such as coatings, solar cells, and electronics.
2. Seismic shielding - Life-saving wave-refraction patterns
Scientists at the University of Missouri have come up with a way to control so-called elastic waves (waves that travel through materials but don't alter their composition) and are looking at ways they could potentially protect structures from earthquakes or tsunamis.
By engraving a geometric microstructure pattern into a steel plate the team have been able to bend or refract waves carrying massive energy around a structure, with the pattern effectively acting as a 'metamaterial cloak', potentially saving both structures and lives. The technique can also be used with other metals and plastics too.
3. Clever concrete - Stronger, self-healing, intelligent
We recently reported on the work of the Materials for Life (M4L) project which is developing a number of ways that concrete can be 'healed' - automatically addressing a range of potential damage at various lengths and timescales. Approaches include development of healing agents, putting bacteria to work, inserting memory polymer tendons, and developing a vascular network that can supply healing agent across a structure over time.
The M4L team aren't the only ones looking at one of the most versatile construction materials. Researchers at Purdue University are exploring how concrete might achieve greater strength, flexibility and resistance. By using cellulose nanocrystals derived from wood fibre, which can be extracted as a by-product of agriculture, bio-energy and paper production, concrete can achieve these 'super powers'.
One factor limiting the strength and durability of today's concrete is that not all of the cement particles are hydrated after being mixed, leaving pores and defects that hamper strength and durability - the new approach increases the hydration of the concrete mixture, allowing more of it to cure and potentially altering the structure of concrete and strengthening it. The team are now looking at how to scale up their work.
4. Self-cleaning and resilient finishes - Perfect, practical, durable protection
A team of researchers at University College London have come up with a new paint coating made from titanium dioxide nanoparticles that can easily be applied to glass and steel and, when combined, with adhesives maintains self-cleaning properties after being wiped, scratched with a knife or scuffed with sandpaper.
Traditionally self-cleaning surfaces, which work by repelling water, often stop working when damaged or exposed to oil - the new, more resilient coating can better deal with wear and tear, making it ideal for a range of construction applications and a wide range of applications.
5. Unbreakable materials - A myriad of materials gain uncharacteristic 'super powers'
Scientists at Caltech led by Julia Greer are looking at how to give materials previously unheard of properties including flaw-tolerance and shape memory. Imagine paper that's un-wettable, thermally insulating and untearable and you can begin to see the enormous potential of the process. That potential is realised through a two-photon lithography technique which is used to create precise polymer nanotrusses. These can be coated in materials like metal or ceramic and hollowed out (removing the polymer) and stacked in a fractal construction. While the process is not suitable for structural or cladding applications, smart windows, wind turbines and battery cells are all possibilities, say researchers.
6. Super wood - Strong, versatile, moisture resistant and transparent?
Wood is an incredibly versatile and resilient construction material but can be prone to moisture absorption, prompting it to shrink or swell, and can also fall foul of a range of pests, not to mention the vagaries of the British climate.
Enter acetylated wood from Accoya - pine bathed in a strong 'vinegar' which, when heated and pressurized, becomes supremely strong and durable as its chemical compounds change. With Forest Stewardship Council (FSC) and Programme for the Endorsement of Forst Certification (PERC) certifications the treated timber is ideal for the construction of structural components, doors and windows, cladding or decking applications.
We also recently reported on work at the KTH Royal Insitute of Technology in producing optically transparent wood with a myriad of potential applications.
7. Steel-making substitutions - Reuse and recycle to drive eco-friendly efficiencies
A team at UNSW Australia's SMaRT Centre have been looking at how waste products can be put to practical use, improving existing processes and materials along the way. The team have enjoyed particular success in substituting waste polymers (derived from old tyres) in electric arc furnace steelmaking, improving energy efficiency, cutting emissions and demand for non-renewable coking coal.
The scientists have also seen results when substituting green petroleum coke with Australian macadamia nut shells in the production of silicon carbide and silicon nitride (used to produce everything from medical equipment to drilling tools to engine linings for performance cars).
Expect similar work to help drive a greener, more sustainable future for the construction industry in the years to come.
8. Perspiring polymer - making buildings sweat to cool down
Cooling buildings down costs money and takes time. Enter a new material from researchers at ETH-Zurich that draws inspiration from the natural efficiencies of sweating to produce a new kind of synthetic matting that can be used to cover the roof of a building. If it rains, the mat soaks up water like a sponge, when it becomes warm in the sunshine, at precisely 32 degrees, it releases water at the surface, extracting heat away from the building.
To create the mats researchers developed a special polymer dubbed 'PNIPAM' and added a water-permeable membrane. The team believe that a mat only a few millimetres thick could save up to 60% of the energy expended for air conditioning in strong sunshine in July.
9. Germ-repellent materials - superbugs on the slide?
The war on bacterial infection is being fought on many fronts and now scientists at the Wong Laboratory for Nature Inspired Engineering have come up with a new way to treat surfaces in a way that means they cannot be colonized by potentially harmful organisms. The team have utilized SLIPS (slippery liquid-infused porous surfaces) technology to ensure that bacteria simply slide right off treated areas. The technique draws inspiration from Pitcher plants and uses nanopores to texture a solid base (perhaps Teflon or metal?) and wick an ultrasmooth lubricant to it meaning everything else (including those germs) simply slide right off the liquid coating.
As well as obvious applications in healthcare and food-preparation scenarios, scientists also point to the ability to use the approach when dealing with dust, ice and graffiti, widening the potential significantly.
10. Constructed by silkworms - 3D printing, inspired by nature
The properties of silk have long been revered - stronger than steel, weight-for-weight, this super-fine super-flexible material clearly has enormous potential when it comes to construction. The problem is that synthetically engineering the material has proved incredibly difficult.
Enter the Mediated Matter team working out of the MIT Media Lab who took a different approach - getting the silkworms to their bidding instead. The team programmed a robotic arm to imitate the way a silkworm deposits silk to build its cocoon, layered the strands over a steel frame and then got live silkworms to complete the structure.
The team believe the experiment points towards a future where architectural structures can be "printed" more efficiently, drawing inspiration from the natural world around us.
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