Small but mighty: How nanomaterials are reshaping the world

Scientists are using molecular engineering to create tiny objects with wild and wonderful properties, thanks to quantum mechanics.

The blue morpho is one of nature’s great illusionists. It stands out even among the attention-grabbing ranks of butterflies, with iridescent wings that shimmer in vibrant turquoise and indigo. But the morpho isn’t blue at all, it’s a muddy brown.

To locate the source of this visual alchemy, you have to zoom way, way in — till you reach an atomic level. Hidden in the morpho’s wings are millions of tiny nanostructures that diffract light in complex ways. When sunlight hits, they make the wing appear a dazzling blue, and a drab bug becomes a showstopper.

Nanostructures measure less than 100 nanometres in one direction (for comparison, a sheet of paper is about 100,000 nanometres thick). On such a tiny scale, the regular laws of physics are moot and quantum mechanics takes over. “Quantum mechanics let you break all the rules,” says Michael Helander, founder of OTI Lumionics, a Toronto company that creates advanced materials for electronics.

Now that scientists are able to delve into this miniscule world, they are becoming increasingly adept at using it as a context for remarkable new feats of engineering. By arranging molecules in very specific ways, they have devised materials that simultaneously function as both electrical conductors and insulators. And they have created forms of carbon that trap almost all visible light — appearing so black they resemble a glitch in the universe. At this tiny scale, the potential for different applications is massive.

Here are four ways Canadian scientists and entrepreneurs are making the most of the wondrous properties of nanostructures.

Climbing the walls

Scientists at the University of Waterloo have developed a miniature robot that can cling to walls and ceilings. The machine is about four centimetres long and comprises a polymer strip that connects two pads containing a smart material inspired by the nanostructures in geckos’ feet. Aided by magnetism, this substance allows the robot to stick to smooth surfaces. Researchers can make the machine move in a vaguely wormlike manner by exposing it to ultraviolet light, which causes the polymer strip to flex, detaching one of the pads and pulling it forward.

While this “soft robot” technology makes for a neat party trick, it also holds the potential to be used in many important ways. Possible outcomes include small machines that could operate within the body during surgical procedures. “I think we’ll see some real applications within the next 10 years,” says Boxin Zhao, who leads the research team.

Making cardboard perform like plastic

Waterloo-based startup Nfinite Nanotech has developed a system for adding ultrathin waterproof coatings to cardboard packaging. Nfinite’s technology is able to apply layers just one atom thick, with enough control and precision to ensure there are no tiny gaps. The result is an overlay that is 1,000 times thinner than a human hair but can block moisture and oxygen. The company says its coatings don’t interfere with recycling or composting cardboard, making them greener alternatives to plastic packaging. In March, Nfinite received $250,000 from multinational packaging firm Amcor to further develop its technology.

Seeing through screens

Like the morpho, your smartphone’s screen relies on an act of microscopic trickery. Though you may think you’re looking at a solid image, “if you zoom in you’ll find that only 18 to 25 percent of it is actually taken up by pixels,” says Helander. The remaining 75 percent is where Helander’s firm, OTI Lumionics, sees an opportunity. It wants to enable facial recognition sensors and cameras to function while mounted behind the display — putting an end to the much-maligned camera notch.

This requires replacing the existing electrically conductive layer that makes a touchscreen function with one that allows light to pass through. OTI Lumionics has created an ultra-thin material that contains millions of tiny holes. It self-assembles during the manufacturing process with a mind-blowing level of precision that lines up the holes with the gaps between pixels. Given the microscopic scale of the variables, it would seem a major achievement to have those stars align even once. But as Helander points out, his company’s real accomplishment lies in the absolute consistency of its mass-production process. “When you’re talking about nanomaterials, a couple of extra atoms you didn’t expect in a slightly different location has a massive impact on your end performance.”

Turning glass into antennas

Halifax’s Meta Materials has found a method to embed a mesh of incredibly thin metal strands within a film that can be applied to glass. The threads are invisible to the naked eye and can be configured for different functions including sending, receiving and blocking radio signals. The company’s innovative material could be applied to windows in tall buildings to improve 5G signals or used to replace the semi-opaque protective screen on microwave doors so that you can finally see what’s going on in there. Perhaps most of interest to Canadians: the mesh can heat up and, because it’s invisible, could be integrated into any vehicle window, including the windshield. Dare we dream about the end of ice scraping?

 
Photo courtesy of the University of Waterloo