Year-End Tech News: Stanene and Nanoparticle Ink

3d.printingThe year of 2013 was also a boon for the high-tech industry, especially where electronics and additive manufacturing were concerned. In fact, several key developments took place last year that may help scientists and researchers to move beyond Moore’s Law, as well as ring in a new era of manufacturing and production.

In terms of computing, developers have long feared that Moore’s Law – which states that the number of transistors on integrated circuits doubles approximately every two years – could be reaching a bottleneck. While the law (really it’s more of an observation) has certainly held true for the past forty years, it has been understood for some time that the use of silicon and copper wiring would eventually impose limits.

copper_in_chips__620x350Basically, one can only miniaturize circuits made from these materials so much before resistance occurs and they are too fragile to be effective. Because of this, researchers have been looking for replacement materials to substitute the silicon that makes up the 1 billion transistors, and the one hundred or so kilometers of copper wire, that currently make up an integrated circuit.

Various materials have been proposed, such as graphene, carbyne, and even carbon nanotubes. But now, a group of researchers from Stanford University and the SLAC National Accelerator Laboratory in California are proposing another material. It’s known as Stanene, a theorized material fabricated from a single layer of tin atoms that is theoretically extremely efficient, even at high temperatures.

computer_chip5Compared to graphene, which is stupendously conductive, the researchers at Stanford and the SLAC claim that stanene should be a topological insulator. Topological insulators, due to their arrangement of electrons/nuclei, are insulators on their interior, but conductive along their edge and/or surface. Being only a single atom in thickness along its edges, this topological insulator can conduct electricity with 100% efficiency.

The Stanford and SLAC researchers also say that stanene would not only have 100%-efficiency edges at room temperature, but with a bit of fluorine, would also have 100% efficiency at temperatures of up to 100 degrees Celsius (212 Fahrenheit). This is very important if stanene is ever to be used in computer chips, which have operational temps of between 40 and 90 C (104 and 194 F).

Though the claim of perfect efficiency seems outlandish to some, others admit that near-perfect efficiency is possible. And while no stanene has been fabricated yet, it is unlikely that it would be hard to fashion some on a small scale, as the technology currently exists. However, it will likely be a very, very long time until stanene is used in the production of computer chips.

Battery-Printer-640x353In the realm of additive manufacturing (aka. 3-D printing) several major developments were made during the year 0f 2013. This one came from Harvard University, where a materials scientist named Jennifer Lewis Lewis – using currently technology – has developed new “inks” that can be used to print batteries and other electronic components.

3-D printing is already at work in the field of consumer electronics with casings and some smaller components being made on industrial 3D printers. However, the need for traditionally produced circuit boards and batteries limits the usefulness of 3D printing. If the work being done by Lewis proves fruitful, it could make fabrication of a finished product considerably faster and easier.

3d_batteryThe Harvard team is calling the material “ink,” but in fact, it’s a suspension of nanoparticles in a dense liquid medium. In the case of the battery printing ink, the team starts with a vial of deionized water and ethylene glycol and adds nanoparticles of lithium titanium oxide. The mixture is homogenized, then centrifuged to separate out any larger particles, and the battery ink is formed.

This process is possible because of the unique properties of the nanoparticle suspension. It is mostly solid as it sits in the printer ready to be applied, then begins to flow like liquid when pressure is increased. Once it leaves the custom printer nozzle, it returns to a solid state. From this, Lewis’ team was able to lay down multiple layers of this ink with extreme precision at 100-nanometer accuracy.

laser-welding-640x353The tiny batteries being printed are about 1mm square, and could pack even higher energy density than conventional cells thanks to the intricate constructions. This approach is much more realistic than other metal printing technologies because it happens at room temperature, no need for microwaves, lasers or high-temperatures at all.

More importantly, it works with existing industrial 3D printers that were built to work with plastics. Because of this, battery production can be done cheaply using printers that cost on the order of a few hundred dollars, and not industrial-sized ones that can cost upwards of $1 million.

Smaller computers, and smaller, more efficient batteries. It seems that miniaturization, which some feared would be plateauing this decade, is safe for the foreseeable future! So I guess we can keep counting on our electronics getting smaller, harder to use, and easier to lose for the next few years. Yay for us!

Sources: extremetech.com, (2)

The Future is Here: Radiowave-Powered Devices

radio-waves-airwaves-spectrumIt sounds like something out of science fiction, using existing existing internet electromagnetic signals to power our devices. But given the concerns surrounding ewaste and toxic materials, anything that could make an impact by eliminating batteries is a welcome idea. And if you live in an urban environment, chances are you’re already cloaked in TV and radio waves invisible that are invisible to the naked eye.

And that’s precisely what researchers at the University of Washington have managed to do. Nine months ago,  Joshua Smith (an associate professor of electrical engineer) and Shyam Gollakota (an assistant professor of computer science and engineering) started investigating how one might harvest energy from TV signals to communicate, and eventually designed two card-like devices that can swap data without using batteries.

wireless-device1Running on what the researchers coined “ambient backscatter,” the device works by capturing existing energy and reflecting it, like a transistor. Currently, our communications and computing devices require a lot of power, even by battery, in order to function. But as Gollakota explains, all of these objects are already creating energy that could be harnessed:

Every object around you is reflecting signals. Imagine you have a desk that is wooden, and it’s reflecting signals, but if you actually make [the desk] iron, it’s going to reflect a much larger amount of energy. We’re trying to replicate that on an analog device.

The new technique is still in its infancy, but shows great promise. Their device transfers data at a rate of one kilobit per second and can only transmit at distances under 2.5 feet. Still, it has exciting implications, they say, for the “Internet of things.” The immediate use for this technology, everything from smart phones to tablets and MP3 players, is certainly impressive.

wireless-deviceBut on their website, the team provides some added examples of applications that they can foresee taking advantage of this technology. Basically, they foresee an age when backscatter devices can be implanted in just about anything ranging from car keys and appliances to structural materials and buildings, allowing people to find them if they get lost, or to be alerting people that there’s some kind of irregularity.

As Smith claimed on the team’s website:

I think the Internet of things looks like many objects that kind of have an identity and state–they can talk to each other. Ultimately, I think people want to view this information… That’s part of the vision. There will be information about objects in the physical world that we can access.

The energy harvester they used for the paper, which they presented at the Association for Computing Machinery’s Special Interest Group on Data Communication in Hong Kong, requires 100 microwatts to turn on, but the team says it has a design that can run on as low as 15 microwatts. Meanwhile, the technique is already capable of communicating location, identity, and sensor data, and is sure to increase in range as efficiency improves.

vortex-radio-waves-348x196The University of Washington presentation took home “best paper” in Hong Kong, and researchers say they’re excited to start exploring commercial applications. “We’ve had emails from different places–sewer systems, people who have been constrained by the fact that you need to recharge things,” Gollakota says. “Our goal for next six months is to increase the data rate it can achieve.”

Combined with Apple’s development of wireless recharging, this latest piece of technology could be ushering in an age of  wireless and remotely powered devices. Everything from smartphones, tablets, implants, and even household appliances could all be running on the radio waves that are already permeating our world. All that ambient radiation we secretly worry is increasing our risks of cancer would finally be put to good use!

And in the meantime, enjoy this video of the UofW’s backscatter device in action: