Thanks to techniques for manipulating materials at the nanoscale and modifying the matter molecule by molecule in the laboratory, engineers are creating new materials with properties worthy of the boldest imagination of science fiction writers.
Although this image might seem a photomontage, the truth is that there’s no trick. What’s floating in the cup, on top of the cappuccino foam, is nothing other than a piece of 20-carat gold made from a revolutionary material a thousand times lighter than metal gold –and almost as graceful as the air– but impossible to distinguish with the eye from solid gold. In chemical terms it’s an aerogel, made up of 98% air, with only 2% solid material. Its creators intend to use it in watches and jewelry, but also as a catalyst and in electronic applications.
Credit: Gustav Nyström and Raffaele Mezzenga /ETH Zurich
Both “Q”, the creator of gadgets and inventions for the famous spy 007, as well as the designers of superhero costumes, would give anything to get a piece of the ultra strong material on which engineers from the Universities of California and Riverside (EE UU) are working, and which they have copied from the mantis shrimp, the animal with the strongest and most impact-resistant weapon known. This Indo-Pacific crustacean needs only deal a blow with one of its front appendages to smash the shell of a snail or the glass of an aquarium. Their strength is due to having a herringbone structure that, if emulated, could be used to build a new generation of almost indestructible armor and cars.
Seeking the cloak of invisibility
An invisibility cloak that makes 3D objects disappear from our view seems more like the fanciful stories of Harry Potter than real life. However, scientists at the Lawrence Berkeley National Laboratory (USA) are working to make this possible. For them, the magic is in the golden nanoantennas with which they create a thin membrane 80 nanometres thick. This layer, when placed around a microscopic object and activated, redirects the light waves that reach it and hides it from the human eye, making it virtually invisible. Although these materials do not yet work with larger objects and a wider range of colours, researchers have not lost hope. “It is potentially scalable to hide macroscopic objects from sight,” said Xiang Zhang, announcing the milestone in the journal Science.
Rigid and flexible might no longer be antonyms, at least in the field of materials science. And it is these two properties, at first view incompatible and opposite, that have been twinned in a surprising metallic foam created by Rob Shepherd, a researcher at Cornell University (USA). Working with silicone foam and an alloy of indium, tin and bismuth, Shepherd and his team have created a material as rigid as a metal that, when heated to 62°C, can change shape and become as soft and flexible as a rubber band. The US Air Force, which financed part of the project, intends to use it in the design of miniplanes so that they can, for example, dive into the water while flying.
What if, whenever the sun went down, instead of switching on streetlights and spotlights to liberate the buildings from the darkness of the night, concrete structures emitted their own light? This is not a utopic idea, but rather the latest creation of José Carlos Rubio, of the Universidad Michoacana de San Nicolás de Hidalgo (UMSNH) in Mexico. The researcher has been working for nine years on modifying the microstructure of cement to achieve a material that absorbs solar energy and returns to the environment. What’s even better is that it retains its properties for a hundred years. This would be ideal, suggests Rubio, for building roads and highways that are self-illuminating, without consuming electricity.
Lighter than a feather
Could a dandelion support the weight of a computer chip? Only if it is made of ultralight metallic microlattices created at the University of California. Using an innovative manufacturing process, a team led by Tobias Schaedler has developed an extremely lightweight metallic compound that is 99.99% air. The 0.01% of solid material (nickel and phosphorus) has been manipulated at the nanoscale by weaving a kind of lattice of interconnected hollow tubes whose walls are only 100 nanometres thick, i.e. a thousand times thinner than a human hair. And despite its lightness, the new metal is tough, supports thermal stress, vibrations and high pressures, in addition to electric shocks.
Superglue made from water
Imagine a type of glue as strong as the union between the cartilage and the bone in your skeleton and made up of 90% water. That’s how powerful the transparent and highly flexible adhesive hydrogel is that has been developed by engineers from the prestigious Massachusetts Institute of Technology (MIT) in the US. For the first time there is a glue that exceeds the adhesive capacity of the natural glue with which mussels cling to cliffs and the surface of ships. As it is biocompatible, in addition to having uses in ships and submarines, it could also be used to manufacture catheters, sensors and biomedical implants.
The days of windows being made from glass may be numbered if the original material created by Swedish researcher Lars Berglund is successful: transparent wood. According to an article in the journal Biomacromolecules, to achieve this feat Berglund first eliminated from the wood the lignin, a component of the plant cell wall that provides opacity. Next he manipulated the wood at the nanoscale to impregnate the pores with a transparent polymer. The optical properties of the polymer and the lignin-free wood merged and –voila!– he got a transparent wood that is strong, durable, inexpensive, made from renewable resources and crystalline. What more could you ask for?