TECH SPECIAL..NANO IS BIG

NANO IS BIG

Scientists are breaking things down to microscopic scales to build products from the ground up. Such an approach has led to stronger materials, faster computers, more effective medicines, and better lifestyles for all of us. And now, like out of sci-fi, it has led to waterproof electronics, spray-on antennas, electricity from plants and even a paint that can gauge a building’s health. Indeed, when it comes to cutting-edge research…

Waterproof electronics
Moisture and electronics don’t go together. And whenever the two meet, the latter emerges worse for wear. But now, two new nanotechnologies – one from Utah-based Zagg and the other by California-based Liquipel – promise to protect devices from water.
Spray any device with Zagg’s HzO solution, and it creates a nano-scale coating that protects electronics against damage from exposure to all sorts of liquids, including oils, synthetic fluids, and even dust and dirt.
“The technology completely seals electronics at the molecular level without affecting the aesthetics or weight of the device,” says Paul Clayson, president and chief executive of HzO. “The sealant is non-toxic and inert to salts, acids, and other corrosives. It withstands extreme temperatures and does not cause electronic devices to retain heat. It is also effective on flexible components such as ribbon cables and connectors.”
Similarly, to waterproof the devices using Liquipel’s patent-pending technology, the gadgets are placed in a vacuum chamber and then bathed in the vapours of the proprietary formulation allowing it to permeate all aspects of the gadget.
In both technologies, the coating – 10 times thinner than human hair – are bonded to the surface at a molecular level. But while ZAGG is looking to tie up with companies where such nanotechnology can be integrated into their existing manufacturing process, you can get your individual device water-proofed by Liquipel for a fee, provided you send your gizmo to the company.
Spray on antennas
Sounds fantastic, doesn’t it? But it’s true. Chamtech Enterprises, based out of Utah in the US, have developed an aerosol formulation that allows you to convert any vertical body – including a tree, pole, wall or fence – into a radio antenna!
“Our material uses thousands of nanocapacitors in a solution that lays out in the right pattern when you spray it over any surface,” says company CEO Anthony Sutera.
In experiments, the inventors sprayed their solution on to a tree and had a US government team monitor the results. “They came back to us and said, ‘hey, this is working better than a standard antenna’,” Sutera boasts.
Consider the applications: No network in any particular room of your house? Frequent call drops? Simply spray the wall opposite
your window with Chamtech’s spray. Lo and behold, you have a signalboosting antenna – and all five network bars on your phone are up and running.
In tests, Chamtech engineers also used a painted tree to transmit on VHF to an airplane 22 kilometres overhead; double the range that they could get on a standard antenna on the ground.
“Think about the highway where you have a painted stripe running down the road. Now imagine broadband connectivity in your vehicle, you have a bunch of antennas all along the journey,” Sutera teases.
The best part, using this technology, you can get rid of all the ugly cell sites and microwave antennas, he says. “No more ugly towers; you just need to paint a few walls and trees.”
Nature’s solar cells
If the geeks at MIT (Massachusetts Institute of Technology) have their way, you might soon be reaching out to your garden plants – nature’s original solar cells – for your electricity needs.
It all began eight years ago when Shuguang Zhang, a research scientist at MIT, built power cells using the photosynthetic structures in plant cells.
Zhang and colleagues harnessed the molecules known as photosystem-I (PS-I) and applied a layer on a glass substrate to build a solar cell that could produce electricity when exposed to light.
But his procedures had a couple of drawbacks: Assembling the PS-I molecules required expensive chemicals and sophisticated lab equipment. Besides, the resulting photovoltaic cell was weak; too inefficient to be put to any practical use...
Now MIT’s Andreas Mershin says the process has been simplified so that almost anyone – including college and even high school science labs – can replicate the procedure allowing scientists around the world to make further improvements.
The new system’s efficiency, Mershin says, is 10,000 times greater than in the previous version, since it converts just 0.1% of sunlight’s energy to electricity.
The scientist believes that once the efficiency reaches 1% or 2%, “it will be good enough to be useful, because the ingredients are so cheap and the processing so simple”.
“You can use anything green, even grass clippings” as the raw material, he says.
While centrifuges were used to concentrate the PS-I molecules, Mershin’s team has proposed a way to achieve this concentration by using inexpensive membranes for filtration.
“The only ingredient to be purchased would be chemicals to stabilize the PS-I molecules, which could be packaged inexpensively in a plastic bag,” Mershin says.
Essentially, within a few years, a villager could actually “take that bag, mix it with any green plant and paint it on the roof” to start producing power, he prophesizes.
Paint for structural safety
Painting antennas on trees is one thing, but boffins at UK’s University of Strathclyde have created a nanotech emulsion that can help detect microscopic faults in buildings, bridges and dams before any structural damage takes place.
Traditional methods used to assess the stability of large structures are rather complex, time consuming – and, of course, include very expensive procedures. However, the smart paint – its developers say – can be simply sprayed onto any surface, with electrodes attached, to detect structural damage long before failure occurs.
“The process of monitoring involves a wireless sensor network,” says Dr Mohamed Saafi of the university’s department of civil engineering. “The paint is interfaced with wireless communication nodes with power harvesting and warning capability to remotely detect any unseen damage such as microcracks.”
For the project, Dr Saafi worked alongside David McGahon, who initiated the research as part of his PhD project.
The paint, McGahon informs, is formed using a recycled waste product known as fly ash and highly-aligned carbon nanotubes. “When mixed, it has a cement-like property which makes it particularly useful in harsh environments, and could shape the future of safety monitoring.”
With fly ash being the main ingredient used to make the paint, it costs just one per cent of the alternative widely-used inspection methods. And tests have shown the paint to be highly effective.
“There are no limitations as to where it could be used and the low-cost nature gives it a significant advantage over the current options available in the industry. The process of producing and applying the paint also gives it an advantage as no expertise is required and monitoring itself is straightforward,” Dr Saafi says.

(Savio D’Souza STOI120219)