Tag Archives: University of Wollongong

Wearable technologies, electric vehicles and conundrums at Wollongong University (Australia)

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A July 25, 2015 news item on Nanowerk announces research at the University of Wollongong designed to address a conundrum (Note: A link has been removed),

UOW’s Institute for Superconducting and Electronic Materials (ISEM) has successfully pioneered a way to construct a flexible, foldable and lightweight energy storage device that provides the building blocks for next-generation batteries needed to power wearable electronics and implantable medical devices (ACS Central Science, “Self-Assembled Multifunctional Hybrids: Toward Developing High-Performance Graphene-Based Architectures for Energy Storage Devices”).

The conundrum researchers have faced in developing miniature energy storage devices, such as batteries and supercapacitors, has been figuring out how to increase the surface area of the device, to store more charge, without making it larger.

A July 27, 2015 University of Wollongong news release by Grant Reynolds, which originated the news item, describes the research in more detail,

To solve this problem, a team of PhD students, led by Dr Konstantin Konstantinov under the patronage of ISEM Director Professor Shi Xue Dou and with the support of Professor Hua Kun Liu, the head of ISEM Energy Storage Division, have developed a three-dimensional structure using a flat-pack self-assembly of three components: graphene, a conductive polymer and carbon nanotubes, which are atom-thick lattice-like networks of carbon formed into cylinders.

Graphene, made from single atom-thick layers of graphite, was a suitable candidate due its electronic performance and mechanical strength.

“We knew in theory that if you can make a sort of carbon skeleton you have a greater surface area and greater surface area means more charge,” Dr Konstantinov said. “If we could efficiently separate the layers of carbon we could then use both surfaces of each layer for charge accumulation. The problem we faced was that fabricating these 3D shapes in practice, not just theory, is a challenging, if not impossible task.”

The solution was to flat-pack the components by building the 3D shape layer-by-layer, much like a miniature exercise in cake decoration. The graphene in liquid form was mixed with the conductive polymer and reduced to solid and the carbon nanotubes carefully inserted between the graphene layers to form a self-assembled flat-packed, wafer-thin supercapacitor material.

“The real challenge was how to assemble these three components into a single structure with the best use of the space available,” PhD student Monirul Islam said. “Getting the proportions or ratios of the components appropriately in order to obtain a composite material with maximum energy storage performance was another challenge.”

Wrong proportions of either ingredient result in a lumpy mess, or a 3D shape that isn’t strong enough to retain the needed flexibility as well as the charge storage ability. There’s also elegance in the simplicity of the team’s design: the researchers dispersed the components in liquid crystalline, which enabled natural chemical interactions to prevent the graphene layers clumping together.

The result was a 3D shape with, thanks to the carbon nanotubes, a massive surface area, excellent charge capacity that is also foldable. It can also be cheaply and easily fabricated without the need for expensive vacuum chambers or sophisticated equipment.

“Our graphene-based flexible composite is highly conductive, lightweight, is able to fold like a roll or stack like a paper in electronic devices to store a huge amount of charge,” Monirul said. “This material can store charge in a second and deliver the charge in superfast speed and will be more lightweight than traditional batteries used in present day’s electronics.”

The ISEM study has been financially supported by the Automotive Australia 2020 CRC as part of its research into electric vehicles. ISEM is the program leader for electrification and plays crucial role for design of next generation electric vehicles A key to unlocking the electric vehicle’s capability is a lightweight and powerful battery pack.

“Our simple fabrication method of eco-friendly materials with increased performance has great potential to be scaled up for use supercapacitor and battery technology. Our next step is to use this material to fabricate flexible wearable supercapacitors with high power density and energy density as well as large scale supercapacitors for electric vehicles.”

Here’s a link to and a citation for the paper,

Self-Assembled Multifunctional Hybrids: Toward Developing High-Performance Graphene-Based Architectures for Energy Storage Devices by Md. Monirul Islam, Seyed Hamed Aboutalebi, Dean Cardillo, Hua Kun Liu, Konstantin Konstantinov, and Shi Xue Dou. ACS Cent. Sci., 2015, 1 (4), pp 206–216 DOI: 10.1021/acscentsci.5b00189 Publication Date (Web): July 2, 2015

Copyright © 2015 American Chemical Society

This appears to be an open access paper.

Yarns of niobium nanowire for small electronic device boost at the University of British Columbia (Canada) and Massachusetts Institute of Technology (US)

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It turns out that this research concerning supercapacitors is a collaboration between the University of British Columbia (Canada) and the Massachusetts Institute of Technology (MIT). From a July 7, 2015 news item by Stuart Milne for Azonano,

A team of researchers from MIT and University of British Columbia has discovered an innovative method to deliver short bursts of high power required by wearable electronic devices.

Such devices are used for monitoring health and fitness and as such are rapidly growing in the consumer electronics industry. However, a major drawback of these devices is that they are integrated with small batteries, which fail to deliver sufficient amount of power required for data transmission.

According to the research team, one way to resolve this issue is to develop supercapacitors, which are capable of storing and releasing short bursts of electrical power required to transmit data from smartphones, computers, heart-rate monitors, and other wearable devices. supercapacitors can also prove useful for other applications where short bursts of high power is required, for instance autonomous microrobots.

A July 7, 2015 MIT news release provides more detail about the research,

The new approach uses yarns, made from nanowires of the element niobium, as the electrodes in tiny supercapacitors (which are essentially pairs of electrically conducting fibers with an insulator between). The concept is described in a paper in the journal ACS Applied Materials and Interfaces by MIT professor of mechanical engineering Ian W. Hunter, doctoral student Seyed M. Mirvakili, and three others at the University of British Columbia.

Nanotechnology researchers have been working to increase the performance of supercapacitors for the past decade. Among nanomaterials, carbon-based nanoparticles — such as carbon nanotubes and graphene — have shown promising results, but they suffer from relatively low electrical conductivity, Mirvakili says.

In this new work, he and his colleagues have shown that desirable characteristics for such devices, such as high power density, are not unique to carbon-based nanoparticles, and that niobium nanowire yarn is a promising an alternative.

“Imagine you’ve got some kind of wearable health-monitoring system,” Hunter says, “and it needs to broadcast data, for example using Wi-Fi, over a long distance.” At the moment, the coin-sized batteries used in many small electronic devices have very limited ability to deliver a lot of power at once, which is what such data transmissions need.

“Long-distance Wi-Fi requires a fair amount of power,” says Hunter, the George N. Hatsopoulos Professor in Thermodynamics in MIT’s Department of Mechanical Engineering, “but it may not be needed for very long.” Small batteries are generally poorly suited for such power needs, he adds.

“We know it’s a problem experienced by a number of companies in the health-monitoring or exercise-monitoring space. So an alternative is to go to a combination of a battery and a capacitor,” Hunter says: the battery for long-term, low-power functions, and the capacitor for short bursts of high power. Such a combination should be able to either increase the range of the device, or — perhaps more important in the marketplace — to significantly reduce size requirements.

The new nanowire-based supercapacitor exceeds the performance of existing batteries, while occupying a very small volume. “If you’ve got an Apple Watch and I shave 30 percent off the mass, you may not even notice,” Hunter says. “But if you reduce the volume by 30 percent, that would be a big deal,” he says: Consumers are very sensitive to the size of wearable devices.

The innovation is especially significant for small devices, Hunter says, because other energy-storage technologies — such as fuel cells, batteries, and flywheels — tend to be less efficient, or simply too complex to be practical when reduced to very small sizes. “We are in a sweet spot,” he says, with a technology that can deliver big bursts of power from a very small device.

Ideally, Hunter says, it would be desirable to have a high volumetric power density (the amount of power stored in a given volume) and high volumetric energy density (the amount of energy in a given volume). “Nobody’s figured out how to do that,” he says. However, with the new device, “We have fairly high volumetric power density, medium energy density, and a low cost,” a combination that could be well suited for many applications.

Niobium is a fairly abundant and widely used material, Mirvakili says, so the whole system should be inexpensive and easy to produce. “The fabrication cost is cheap,” he says. Other groups have made similar supercapacitors using carbon nanotubes or other materials, but the niobium yarns are stronger and 100 times more conductive. Overall, niobium-based supercapacitors can store up to five times as much power in a given volume as carbon nanotube versions.

Niobium also has a very high melting point — nearly 2,500 degrees Celsius — so devices made from these nanowires could potentially be suitable for use in high-temperature applications.

In addition, the material is highly flexible and could be woven into fabrics, enabling wearable forms; individual niobium nanowires are just 140 nanometers in diameter — 140 billionths of a meter across, or about one-thousandth the width of a human hair.

So far, the material has been produced only in lab-scale devices. The next step, already under way, is to figure out how to design a practical, easily manufactured version, the researchers say.

“The work is very significant in the development of smart fabrics and future wearable technologies,” says Geoff Spinks, a professor of engineering at the University of Wollongong, in Australia, who was not associated with this research. This paper, he adds, “convincingly demonstrates the impressive performance of niobium-based fiber supercapacitors.”

Here’s a link to and a citation for the paper,

High-Performance Supercapacitors from Niobium Nanowire Yarns by Seyed M. Mirvakili, Mehr Negar Mirvakili, Peter Englezos, John D. W. Madden, and Ian W. Hunter. ACS Appl. Mater. Interfaces, 2015, 7 (25), pp 13882–13888 DOI: 10.1021/acsami.5b02327 Publication Date (Web): June 12, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

A new bio-ink, inkjet printers, and printing human cells at Australia’s University of Wollongong

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Sometimes I look at my printer and just shake my head at the thought that one day it might produce living cells if the researchers at University of  Wollongong (New South Wales, Australia) have their way. From the Nov. 16, 2012 news item on phys.org,

Researchers have been aware for some time of the potential for using commercially available inkjet printer heads to print living human cells into 3D structures, but design of the actual ink capable of carrying cells through the printer has been a challenge.

The ARC Centre of Excellence for Electromaterials Science at UOW has led a team of scientists including Cameron Ferris, Dr Kerry Gilmore, Dr Stephen Beirne, Dr Donald McCallum, Professor Gordon Wallace and Associate Professor Marc in het Panhuis to develop a new bio-ink that improves the viability of living cells and allows better control of cell positioning through the printing process.

“To date, none of the available inks has been optimised in terms of both printability and cell suspending ability,” according to ACES Associate Researcher Cameron Ferris.

“Our new bio-ink is printable and cell-friendly, preventing cell settling and allowing controlled deposition of cells.”

The Nov. 15, 2012 University of Wollogong news release, which originated the news item, provides some detail about what makes this new bio-ink exciting,

The 2D structures being printed with the bio-ink enables exquisite control over cell distribution and this already presents exciting opportunities to improve drug screening and toxicology testing processes. Building on this, 3D bio-printing, with which patient-specific tissue replacements could be fabricated, is within the grasp of researchers.

The abstract for the researchers’ paper in Biomaterials helped me to build my understanding of this innovation,

Drop-on-demand bioprinting allows the controlled placement of living cells, and will benefit research in the fields of tissue engineering, drug screening and toxicology. We show that a bio-ink based on a novel microgel suspension in a surfactant-containing tissue culture medium can be used to reproducibly print several different cell types, from two different commercially available drop-on-demand printing systems, over long printing periods. The bio-ink maintains a stable cell suspension, preventing the settling and aggregation of cells that usually impedes cell printing, whilst meeting the stringent fluid property requirements needed to enable printing even from many-nozzle commercial inkjet print heads. This innovation in printing technology may pave the way for the biofabrication of multi-cellular structures and functional tissue.

You can access the paper (free access) but you must be registered (it’s free) with RSC (Royal Society of Chemistry) Publishing. Here’s a link and the citation,

Bio-ink for on-demand printing of living cells

Cameron J. Ferris ,  Kerry J. Gilmore ,  Stephen Beirne ,  Donald McCallum ,  Gordon G. Wallace and Marc in het Panhuis

Biomater. Sci., 2013, Advance Article

DOI: 10.1039/C2BM00114D
Received 09 Aug 2012, Accepted 11 Oct 2012
First published on the web 05 Nov 2012

Even more helpful than the abstract and assuming you’re not ready to read the paper is Jennifer Newton’s Nov. 7, 2012 article for the RSC’s Chemistry World,

‘The first bio-inks used in drop-on-demand cell printing were simple salt solutions,’ says Marc in het Panhuis, who was part of the research team at the University of Wollongong. ‘The cells in these inks settled and aggregated quickly, which impeded printing. Cell viability can also be compromised if the salt concentration is too high.’

Other bio-inks include low viscosity biopolymer solutions, which are known to slow cell settling. The team’s bio-ink consists of a biopolymer – gellan gum – and two surfactants in a standard tissue culture medium. The surfactants – Novec FC4430 and Poloxamer 188 – reduce surface tension, allowing optimal inkjet printing, and protect the cells from fluid-mechanical damage.

The cells do not settle and aggregate because the biopolymer creates a structured network of micro-gel particles that keep the cells suspended in the gel. However, the bio-ink remains printable as the network is not rigid and is easily broken down during printing. ‘Our bio-ink allowed us to print multiple cell types over long printing periods without changing print heads or replenishing ink solutions,’ says in het Panhuis.

There are more details in Newton’s article and the image that accompanies it is quite striking.

Aussies, Yanks, Canucks, and Koreans collaborate on artificial muscles

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I received a media release (from the University of British Columbia [UBC]) about artificial muscles. I was expecting to see Dr. Hongbin Li’s name as one of the researchers but this is an entirely different kind of artificial muscle. Dr. Li works with artificial proteins to create new biomaterials (my May 5, 2010 posting). This latest work published in Science Express, Oct. 13, 2011,  involves carbon nanotubes and teams from Australia, Canada, Korea, and the US. From the Oct. 13, 2011, UBC media release,

An international team of researchers has invented new artificial muscles strong enough to rotate objects a thousand times their own weight, but with the same flexibility of an elephant’s trunk or octopus limbs.

In a paper published online today on Science Express, the scientists and engineers from the University of British Columbia, the University of Wollongong in Australia, the University of Texas at Dallas and Hanyang University in Korea detail their innovation. The study elaborates on a discovery made by research fellow Javad Foroughi at the University of Wollongong.

Using yarns of carbon nanotubes that are enormously strong, tough and highly flexible, the researchers developed artificial muscles that can rotate 250 degrees per millimetre of muscle length. This is more than a thousand times that of available artificial muscles composed of shape memory alloys, conducting organic polymers or ferroelectrics, a class of materials that can hold both positive and negative electric charges, even in the absence of voltage.

Here’s how the UBC media release recounts the story of these artificial muscles (Aside: The Australians take a different approach; I haven’t seen any material from the University of Texas at Dallas or the University of Hanyang),

The new material was devised at the University of Texas at Dallas and then tested as an artificial muscle in Madden’s [Associate Professor, John Madden, Dept. of Electrical and Computer Engineering] lab at UBC. A chance discovery by collaborators from Wollongong showed the enormous twist developed by the device. Guided by theory at UBC and further experiments in Wollongong and Texas, the team was able to extract considerable torsion and power from the yarns.

The Australians, not unnaturally focus on their own contributions, and, somewhat unexpectedly discuss nanorobots. From the ARC (Australian Research Council) Centre of Excellence for Electromaterials Science (ACES) at the University of Wollongong news release (?) [ETA Oct. 17, 2011: I forgot to include a link to the Australian news item; and here’s a link to the Oct. 16, 2011 Australian news item on Nanowerk] ,

The possibility of a doctor using tiny robots in your body to diagnose and treat medical conditions is one step closer to becoming reality today, with the development of artificial muscles small and strong enough to push the tiny Nanobots along.

Although Nanorobots (Nanobots) have received much attention for the potential medical use in the body, such as cancer fighting, drug delivery and parasite removal, one major hurdle in their development has been the issue of how to propel them along in the bloodstream.

An international collaborative team led by researchers at UOW’s Intelligent Polymer Research Institute, part of the ARC Centre of Excellence for Electromaterials Science (ACES), have developed a new twisting artificial muscle that could be used for propelling nanobots.   The muscles use very tough and highly flexible yarns of carbon nanotubes (nanoscale cylinders of carbon), which are twist-spun into the required form.  When voltage is applied, the yarns rotate up to 600 revolutions per minute, then rotate in reverse when the voltage is changed.

Due to their complexity, conventional motors are very difficult to miniaturise, making them unsuitable for use in nanorobotics.  The twisting artificial muscles, on the other hand, are simple and inexpensive to construct either in very long, or in millimetre lengths.

Interesting, non?

There’s an animation illustrating the nanorobots and the muscles,

In the animated video below, you first see a few bacteria like creatures swimming about. Their rotating flagella are highlighted with some detail of the flagella motor turning the “hook” and “filament” parts of the tail. We next see a similar type of rotating tail produced by a length of carbon nanotube thread that is inside a futuristic microbot. The yarn is immersed in a liquid electrolyte along with another electrode wire. Batteries and an electrical circuit are also inside the bot. When a voltage is applied the yarn partially untwists and turns the filament. Slow discharging of the yarn causes it to re-twist. In this way, we can imagine the micro-bot is propelled along in a series of short spurts.

I think the graphics resemble conception complete with sperm and eggs but I can see the nanorobots too. Here’s your chance to take a look,

ETA Oct. 14, 2011 11:20 am PST: I found a copy of the University of Texas at Dallas news release posted on Oct. 13, 2011 at Nanowerk. No mention of nanobots but if you’re looking for additional technical explanations, this would be good to read.