Tag Archives: thin-film

Nano for car lubricants and for sensors on dashboards

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I have two car-oriented news items today. The first concerns the introduction of carbon nanospheres into lubricants as a means of reducing friction. From a March 5, 2015 news item on Nanowerk,

Tiny, perfectly smooth carbon spheres added to motor oil have been shown to reduce friction and wear typically seen in engines by as much as 25 percent, suggesting a similar enhancement in fuel economy.

The researchers also have shown how to potentially mass-produce the spheres, making them hundreds of times faster than previously possible using ultrasound to speed chemical reactions in manufacturing.

“People have been making these spheres for about the last 10 years, but what we discovered was that instead of taking the 24 hours of synthesis normally needed, we can make them in 5 minutes,” said Vilas Pol, an associate professor of chemical engineering at Purdue University.

The spheres are 100-500 nanometers in diameter, a range that generally matches the “surface roughness” of moving engine components.

“So the spheres are able to help fill in these areas and reduce friction,” said mechanical engineering doctoral student Abdullah A. Alazemi.

A March 4, 2015 Purdue University news release by Emil Venere, which originated the news item, elaborates on the impact this finding could have (Note: A link has been removed),

Tests show friction is reduced by 10 percent to 25 percent when using motor oil containing 3 percent of the spheres by weight.

…

“Reducing friction by 10 to 25 percent would be a significant improvement,” Sadeghi said. “Many industries are trying to reduce friction through modification of lubricants. The primary benefit to reducing friction is improved fuel economy.”

Friction is greatest when an engine is starting and shutting off, so improved lubrication is especially needed at those times.

“Introducing microspheres helps separate the surfaces because the spheres are free to move,” Alazemi said. “It also is possible that these spheres are rolling and acting as little ball bearings, but further research is needed to confirm this.” [emphasis mine]

Findings indicate adding the spheres did not change the viscosity of the oil.

“It’s very important not to increase the viscosity because you want to maintain the fluidity of the oil so that it can penetrate within engine parts,” Alazemi said.

The spheres are created using ultrasound to produce bubbles in a fluid containing a chemical compound called resorcinol and formaldehyde. The bubbles expand and collapse, generating heat that drives chemical reactions to produce polymer particles. These polymeric particles are then heated in a furnace to about 900 degrees Celsius, yielding the perfectly smooth spheres.

“A major innovation is that professor Pol has shown how to make lots of these spheres, which is important for potential industrial applications,” Sadeghi said.

Etacheri said, “Electron microscopy images and Raman spectra taken before and after their use show the spheres are undamaged, suggesting they can withstand the punishing environment inside engines and other machinery.”

Funding was provided by Purdue’s School of Chemical Engineering. Electron microscopy studies were performed at the Birck Nanotechnology Center in Purdue’s Discovery Park.

Future research will include work to determine whether the spheres are rolling like tiny ball bearings or merely sliding. A rolling mechanism best reduces friction and would portend well for potential applications. Future research also will determine whether the resorcinol-formaldehyde particles might themselves be used as a lubricant additive without heating them to produce pure carbon spheres.

I’m not sure why the researcher is referring to microspheres as the measurements are at the nanoscale, which should mean these are ‘nanospheres’ or, as the researchers have it in the title for their paper, ‘submicrometer spheres’.

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

Ultrasmooth Submicrometer Carbon Spheres as Lubricant Additives for Friction and Wear Reduction by Abdullah A. Alazemi, Vinodkumar Etacheri, Arthur D. Dysart, Lars-Erik Stacke, Vilas G. Pol, and Farshid Sadeghi. ACS Appl. Mater. Interfaces, Article ASAP DOI: 10.1021/acsami.5b00099 Publication Date (Web): February 17, 2015
Copyright © 2015 American Chemical Society

This paper is behind a paywall but there is an instructive image freely available,

This image taken with an electron microscope shows that tiny carbon spheres added to motor oil reduce friction and wear typically seen in engines by as much as 25 percent, suggesting a similar enhancement in fuel economy. Purdue researchers also have shown how to potentially mass-produce the spheres. (Purdue University image)

This image taken with an electron microscope shows that tiny carbon spheres added to motor oil reduce friction and wear typically seen in engines by as much as 25 percent, suggesting a similar enhancement in fuel economy. Purdue researchers also have shown how to potentially mass-produce the spheres. (Purdue University image)

My second car item concerns thin films and touch. From a March 5, 2015 news item on Azonano (Note: A link has been removed),,

Canatu, a leading manufacturer of transparent conductive films, has in partnership with Schuster Group [based in Germany] and Display Solution AG [based in Germany], showcased a pioneering 3D encapsulated touch sensor for the automotive industry.

The partnership is delivering the first ever, button free, 3D shaped true multitouch panel for automotives, being the first to bring much anticipated touch applications to dashboards and paneling. The demonstrator provides an example of multi-functional display with 5 finger touch realized in IML [in mould labeling] technology.

A March 5, 2015 Canatu press release, which originated the news item, provides more details about the technology and some insight into future plans,

The demonstrator provides an example of multi-functional display with 5 finger touch realized in IML technology. The integration of touch applications to dashboards and other paneling in cars has long been a desired by automotive designers but a suitable technology was not available. Finally the technology is now here. Canatu’s CNB™ (Carbon NanoBud®) In-Mold Film, with its unique stretch properties provides a clear path to the eventual replacement of mechanical controls with 3D touch sensors. The touch application was made using an existing mass manufacturing tool and industry standard processes.

Specifically designed for automobile center consoles and dashboards, household machines, wearable devices, industrial user interfaces, commercial applications and consumer devices, CNB™ In-Mold Films can be easily formed into shape. The film is first patterned to the required touch functionality, then formed, then back-molded by injection molding, resulting in a unique 3D shape with multitouch functionality.

With a bending radius of 1mm, CNB™ In-Mold Films can bring touch to almost any surface imaginable. The unique properties of CNB™ In-Mold Films are unmatched as no other film on the market can be stretched 120% and molded without losing their conductivity.

You can find out more about Canatu, based in Finland, here.

Buckypaper technology in Florida (US) receives $!.4M grant

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Just after suggesting (as per my Nov. 26, 2013 posting) that Florida is quietly becoming a center for nanotechnology efforts in the US, there’s a $1.4M funding announcement for Florida State University’s High-Performance Materials Institute (HPMI. From the Nov. 27, 2013 news item on Nanowerk,

Florida State researchers have been awarded more than $1.4 million from the National Science Foundation to develop a system that will produce large amounts of a state-of-the-art material made from carbon nanotubes that researchers believe could transform everything from the way airplanes are built to how prosthetic limbs fit the human body.

“The goal is clear — to show industry the ability to use this in large-scale quantities,” said Richard Liang, director of FSU’s High-Performance Materials Institute (HPMI) and a professor for the FAMU-FSU College of Engineering. “We’re looking at a more efficient, cost effective way to do this.”

The Nov. 26, 2013 Florida State University (FSU) news release (also on EurekAlert), which originated the news item, provides greater detail about buckypaper, the team’s research work, and the team’s hopes for this grant,

The material, buckypaper, is a feather-light sheet made of carbon nanotubes that is being tested in electronics, energy, medicine, space and transportation.  The aviation industry, for example, is doing tests with buckypaper, and it’s projected that it could replace metal shielding in the Boeing 787, currently made up of 60 miles of cable.

Engineers believe that replacing the cable with buckypaper could reduce the weight of the Boeing 787 by as much as 25 percent.

Florida State researchers have been engaged in other projects with buckypaper as well, including the use of the material in creating more advanced and comfortable prosthetic sockets for amputee patients and multifunctional lightweight composites for aerospace applications.

As revolutionary as buckypaper technology is, a major hurdle for its future use is that it can take two or more hours and can cost as much as $500 to make just a small 7-inch by 7-inch piece.  Companies like Boeing need large amounts of it to use on an aircraft.

However, the current process is neither fast nor cheap.

So, Liang will spend the next four years developing a process to produce large-scale amounts of buckypaper. The process and materials would then be patented and marketed to meet the demands of the industrial partners.

Liang will be joined on the project by Arda Vanli, an HPMI researcher and an assistant professor in the Department of Industrial and Manufacturing Engineering, as well as researchers from Georgia Institute of Technology.

The US National Science Foundation (NSF) webpage listing the award describes the specific research being undertaken and introduces the term ‘Bucky-tapes’,

Award Abstract #1344672
SNM: Roll-to-Roll Manufacturing of High Quality Bucky-tape with Aligned and Crosslinked Carbon Nanotubes Through In-line Sensing and Control

…

Carbon nanotubes (CNTs) demonstrate amazing properties; however, currently only a fraction of these properties can be transferred into products that can be used by engineers and consumers. To effectively transfer CNTs? properties into useful products requires a method to efficiently align and covalently interconnect the CNTs into tailored architectures at the nanoscale. This project will establish the fundamental understanding and foundation for using CNTs to make thin sheet materials, called Bucky-tapes, which can be rapidly produced in roll form and scaled-up for industrial applications. The proposed method will use a modified die-casting manufacturing process utilizing the self-repelling effects of selected flow media. In-situ ultra-violet (UV) reaction chemistry can covalently interconnect the CNTs rapidly to improve the load transfer and thermal and electronic transport properties of CNT networks. In-line multi-stage stretching of the web could orient the randomly dispersed interconnected CNT networks into specific patterns to provide greater strength and optimized transport properties. In-line Raman spectra monitoring and multistage process models will provide affordable, closed loop quality control and variation reduction methods for a high quality consistent nanomanufacturing process. A prototype will be built to demonstrate the continuous roll-to-roll process for manufacturing strong Bucky-tapes with high electrical and thermal conductivity, and low manufacturing cost.

This project can transform CNT thin films networks from a lab-scale demonstration material into commercially viable products with superior properties potentially surpassing the state-of-the-art carbon fiber material. The continuous Bucky-tapes can lead to new materials applications in aerospace, electronics, energy, medicine, and transportation. For example, continuous Bucky-tape could replace metal shielding of 60 miles of cables in the Boeing 787 and reduce cable weight by 25%. The education and outreach plan will expose especially under-represented students to molecular design, nanomanufacturing process development and quality control, structure-property relationship studies. Application oriented materials-by-design and nanomanufacturing process development will motivate students into nanotechnology, manufacturing and new materials development.

I had mentioned this team’s work on buckypaper (or are they now calling it Bucky-tape?) in an Oct. 4, 2011 posting which features a video about buckypaper and in which I noted the possible applications for buckypaper closely mirror those for CNC (cellulose nanocrystals) or, as it’s also known,  NCC (nanocrystalline cellulose).

You can check out Florida State University’s High Performance Materials Institute here.

Making solar panels beautiful

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Researchers at Germany’s Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena are working on ways to make solar panels more aesthetically pleasing according to a July 1, 2013 news item on Azonano,

Until now, designers of buildings have no choice but to use black or bluish-gray colored solar panels. With the help of thin-film technologies, researchers have now been able to turn solar cells into colorful creations.

Covering a roof or a façade with standard solar cells to generate electricity will change a building’s original appearance – and not always for the better. At present only dark solar panels are widely available on the market. “Not enough work has been done so far on combining photovoltaics and design elements to really do the term ‘customized photovoltaics’ justice,” says Kevin Füchsel, project manager at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena.

But things are changing. The IOF physicist has been focusing for the last four years on nanostructured solar cells suitable for mass production as part of a junior research group funded by Germany’s Federal Ministry for Education and Research (BMBF). Together with a Fraunhofer team and scientists from the Friedrich-Schiller University in Jena, the group of optics specialists is looking for cost-effective techniques and manufacturing processes to increase both the efficiency of solar panels and the design flexibility they give architects and designers.

Here’s photomontage illustrating Füchsel’s ideas,

The photomontage shows how the Fraunhofer IAO building in Stuttgart could be fitted with an “efficient design” solar façade. © Fraunhofer IOF

The photomontage shows how the Fraunhofer IAO building in Stuttgart could be fitted with an “efficient design” solar façade.
© Fraunhofer IOF

The July 1, 2013 Fraunhofer Institute news release, which originated the news item, describes Füchsel’s work in more detail,

Füchsel is currently working with his “efficient design” team on the fundamentals of how to make colored solar cells from paper-thin silicon wafers. These will be particularly suited to designs for decorative façades and domestic roofs. The silicon semiconductor material, just a few micrometers thick, absorbs light and turns it into electricity. To enable lots of light to reach the silicon substrate, the semiconductor layer is given an optically neutral protective barrier (insulator), onto which a hundred-nanometer-thick oxide layer is applied. This transparent conductive oxide (TCO) conducts electricity, and is there primarily to guide as many light particles as possible to the semiconductor layer below. “TCO has a lower refractive index than silicon, so it works as an anti-reflective coating,” Füchsel says.

The simple construction of this SIS (semiconductor-insulator-semiconductor) solar cell, with its transparent outer layer, has a further advantage: Not only does it capture more light, it means solar panels can be made in different colors and shapes. “The color comes from changing the physical thickness of the transparent conductive oxide layer, or modifying its refractive index,” Füchsel says. The Jena-based researchers have thus managed to combine wafer-based silicon with processes borrowed from thin-film photovoltaics. They are also pioneering the use of innovative coating materials. Indium tin oxide is the most common material used today, but it is expensive.  The IOF laboratory is working on how to use cheaper zinc oxide with added aluminum. New opportunities in façade design are being opened up not just by SIS solar cells, however, but also by dye solar modules and flexible organic solar cells.

But how does color affect the efficiency of these new SIS modules? “Giving solar cells color doesn’t really affect their efficiency. The additional transparent TCO layer has barely any impact on the current yield,” Füchsel says. Simulations showed that SIS cells could be up to 20 percent efficient. In practice, the efficiency depends on the design of the solar panels and the direction the building faces. But not every color allows you to generate the same amount of electricity. There are restrictions for example with certain blends of red, blue and green.

…

To connect several solar cells to create a single module the IOF scientist will use laser-based optical welding processes. They enable accurate work at a micrometer scale and do not damage the surrounding material. Researchers are also developing an inkjet printing process to contact the conductive TCO later on the silicon wafer. This will make manufacturing faster and allow additional degrees of flexibility in design. SIS solar cells could even be used to make large billboards that produce their own electricity. Patents already cover the production of colored cells, as well as the ability to integrate design elements into solar panels and whole modules. “This opens up numerous possibilities to use a building to communicate information, displaying the name of a company or even artistic pictures,” Füchsel says.

I look forward to a more beautiful future.