Tag Archives: foam

A soft heart from Cornell University (US)

Caption: This is an artificial foam heart created by Rob Shepherd and his engineering team at Cornell University. Credit: Cornell University

Caption: This is an artificial foam heart created by Rob Shepherd and his engineering team at Cornell University.
Credit: Cornell University

It’s not exactly what I imagined on seeing the words “foam heart” but this is what researchers at Cornell University have produced as a ‘working concept’. From an Oct. 14, 2015 Cornell University news release (also on EurekAlert but dated Oct. 15, 2015) describes the research in more detail,

Cornell University researchers have developed a new lightweight and stretchable material with the consistency of memory foam that has potential for use in prosthetic body parts, artificial organs and soft robotics. The foam is unique because it can be formed and has connected pores that allow fluids to be pumped through it.

The polymer foam starts as a liquid that can be poured into a mold to create shapes, and because of the pathways for fluids, when air or liquid is pumped through it, the material moves and can change its length by 300 percent.

While applications for use inside the body require federal approval and testing, Cornell researchers are close to making prosthetic body parts with the so-called “elastomer foam.”

“We are currently pretty far along for making a prosthetic hand this way,” said Rob Shepherd, assistant professor of mechanical and aerospace engineering, and senior author of a paper appearing online and in an upcoming issue of the journal Advanced Materials. Benjamin Mac Murray, a graduate student in Shepherd’s lab, is the paper’s first author.

In the paper, the researchers demonstrated a pump they made into a heart, mimicking both shape and function.

The researchers used carbon fiber and silicone on the outside to fashion a structure that expands at different rates on the surface – to make a spherical shape into an egg shape, for example, that would hold its form when inflated.

“This paper was about exploring the effect of porosity on the actuator, but now we would like to make the foam actuators faster and with higher strength, so we can apply more force. We are also focusing on biocompatibility,” Shepherd said.

Cornell has made a video of researcher Rob Shepherd describing the work,

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

Poroelastic Foams for Simple Fabrication of Complex Soft Robots by Benjamin C. Mac Murray, Xintong An, Sanlin S. Robinson, Ilse M. van Meerbeek, Kevin W. O’Brien, Huichan Zhao, andRobert F. Shepherd. Advanced Materials DOI: 10.1002/adma.201503464 Article first published online: 19 SEP 2015

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Bubblicious

Mathematicians love their bubbles according to the May 9, 2013 news release on EurekAlert,

Two University of California, Berkeley, researchers have now described mathematically the successive stages in the complex evolution and disappearance of foamy bubbles, a feat that could help in modeling industrial processes in which liquids mix or in the formation of solid foams such as those used to cushion bicycle helmets.

Applying these equations, they created mesmerizing computer-generated movies showing the slow and sedate disappearance of wobbly foams one burst bubble at a time.

The applied mathematicians, James A. Sethian and Robert I. Saye, will report their results in the May 10 issue of Science. Sethian, a UC Berkeley professor of mathematics, leads the mathematics group at Lawrence Berkeley National Laboratory (LBNL). Saye will graduate from UC Berkeley this May with a PhD in applied mathematics.

The May 9, 2013 University of California Berkeley news release by Robert Sanders, which originated the news release on EurekAlert, describes a serious side to the work,

“This work has application in the mixing of foams, in industrial processes for making metal and plastic foams, and in modeling growing cell clusters,” said Sethian. “These techniques, which rely on solving a set of linked partial differential equations, can be used to track the motion of a large number of interfaces connected together, where the physics and chemistry determine the surface dynamics.”

The problem with describing foams mathematically has been that the evolution of a bubble cluster a few inches across depends on what’s happening in the extremely thin walls of each bubble, which are thinner than a human hair.

“Modeling the vastly different scales in a foam is a challenge, since it is computationally impractical to consider only the smallest space and time scales,” Saye said. “Instead, we developed a scale-separated approach that identifies the important physics taking place in each of the distinct scales, which are then coupled together in a consistent manner.”

Saye and Sethian discovered a way to treat different aspects of the foam with different sets of equations that worked for clusters of hundreds of bubbles. One set of equations described the gravitational draining of liquid from the bubble walls, which thin out until they rupture. Another set of equations dealt with the flow of liquid inside the junctions between the bubble membranes. A third set handled the wobbly rearrangement of bubbles after one pops.

Using a fourth set of equations, the mathematicians solved the physics of a sunset reflected in the bubbles, taking account of thin film interference within the bubble membranes, which can create rainbow hues like an oil slick on wet pavement. Solving the full set of equations of motion took five days using supercomputers at the LBNL’s National Energy Research Scientific Computing Center (NERSC).

The mathematicians next plan to look at manufacturing processes for small-scale new materials.

Here’s a still image from the video the researchers created to demonstrate their work on soap bubble clusters,

A soap bubble cluster shown with physically accurate thin-film interference, which produces rainbow hues like an oil slick on pavement. A beach at sunset is reflected in the bubbles. Courtesy: UC Berkeley

A soap bubble cluster shown with physically accurate thin-film interference, which produces rainbow hues like an oil slick on pavement. A beach at sunset is reflected in the bubbles. Courtesy: UC Berkeley

You can find the full animation here.

Science policy, innovation and more on the Canadian 2010 federal budget; free access in the true north; no nano for Van Gogh’s The Bedroom; frogs, foam and biofuels

There are more comments about Canada’s 2010 federal budget on the Canadian Science Policy Centre website along with listings of relevant news articles which they update regularly. There’s also a federal budget topic in the forums section but it doesn’t seem have attracted much commentary yet.

The folks at The Black Hole blog offer some pointed commentary with regard to the budget’s treatment of post doctorate graduates. If I understand the comments correctly, the budget has clarified the matter of taxation, i. e., post doctoral grants are taxable income, which means that people who were getting a break on taxes are now losing part of their income. The government has also created a new class of $70,000 post doctoral grants but this will account for only 140 fellowships. With some 6000 post doctoral fellows this means only 2% of the current pool of applicants will receive these awards. Do read The Black Hole post as they clarify what this means in very practical terms.

There’s been another discussion outcome from the 2010 budget, a renewed interest in innovation. I’m kicking off my ‘innovation curation efforts’ with this from an editorial piece by Carol Goar in the Toronto Star,

Five Canadian finance ministers have tried to crack the productivity puzzle. All failed. Now Jim Flaherty is taking a stab at it.

Here is the conundrum: We don’t use our brainpower to create new wealth. We have a highly educated population, generous tax incentives for research and development and lower corporate tax rates than any leading economic power. Yet our businesses remain reluctant to invest in new products and technologies (with a few honourable exceptions such as Research in Motion, Bombardier and Magna). They don’t even capitalize on the exciting discoveries made in our universities and government laboratories.

Economists are starting to ask what’s wrong. Canada ranked 14th in business spending on research and development – behind all the world’s leading industrial powers and even smaller nations such as Belgium and Ireland – in the latest statistical roundup by the Organization for Economic Cooperation and Development.

I believe she’s referring to the 2009 OECD scorecard in that last bit (you can find the Canada highlights here).

There are many parts to this puzzle about why Canadians and their companies are not innovative.  Getting back to Goar’s piece,

Kevin Lynch, who served as Stephen Harper’s top adviser from 2006 to 2009 [and is now the vice-chair of the Bank of Montreal Financial Group], has just written an article in Policy Options, an influential magazine, laying the blame squarely on corporate Canada. He argues that, unless business leaders do their part, it makes little sense to go on spending billions of dollars on research and development. “In an era of fiscal constraint, there has to be a compelling narrative to justify new public investments when other areas are being constrained,” he says.

Here’s a possible puzzle piece, in yesterday’s (March 15, 2010) posting I noted a study by academic, Mary J. Benner, where she pointed out that securities analysts do not reward/encourage established US companies such as Polaroid (now defunct) and Kodak to adopt new technologies. I would imagine that the same situation exists here in Canada.

For another puzzle piece: I’ve made mention of the mentality that a lot of entrepreneurs (especially in Canadian high tech) have and see confirmation  in a Globe and Mail article by Simon Avery about the continuing impact of the 2000 dot com meltdown where he investigates some of the issues with venture capital and investment as well as this,

“It’s a little bit about getting into the culture of winning, like the Olympics we just had,” says Ungad Chadda, senior vice-president of the Toronto Stock Exchange. “I don’t think the technology entrepreneurs around here are encouraged and supported to think beyond the $250-million cheque that a U.S. company can give them.”

One last comment from  Kevin Lynch (mentioned in the second of the Goar excerpts) about innovation and Canada from his recent opinion piece in the Globe and Mail,

A broader public dialogue is essential. We need to make the question “What would it take for Canada to be an innovative economy for the 21st century?” part of our public narrative – partly because our innovation deficit is a threat to our competitiveness and living standards, and partly because we can be a world leader in innovation. We should aspire to be a nation of innovators. We should rebrand Canada as technologically savvy, entrepreneurial and creative.

Yes, Mr. Lynch a broader dialogue would be delightful but there does seem to be an extraordinary indifference to the notion from many quarters. Do I seem jaundiced? Well, maybe that’s because I’ve been trying to get some interest in having a Canadian science policy debate and not getting very far with it. In principle, people call for more dialogue but that requires some effort to organize and a willingness to actually participate.

(As for “rebranding”, is anyone else tired of hearing that word or its cousin branding?)

On a completely other note, the University of Ottawa has announced that it is supporting open access to its faculty’s papers with institutional funding. From the news release,

According to Leslie Weir, U of Ottawa’s chief librarian, the program encompasses several elements, including a new Open Access (or OA) repository for peer-reviewed papers and other “learning objects”; an “author fund” for U of Ottawa researchers to help them cover open-access fees charged by journal publishers; a $50,000-a-year budget to digitize course materials and make them available to anyone through the repository; and support for the University of Ottawa Press’s OA journals.

But the university stopped short of requiring faculty members to deposit their papers with the new repository. “We all agreed that incentives and encouragement was the best way to go,” said Ms. Weir, who worked on the program with an internal group of backers, including Michael Geist, professor of intellectual property law, and Claire Kendall, a professor in the faculty of medicine who has been active in OA medical journals.

There is some criticism of the decision to make the programme voluntary. Having noticed the lack of success that voluntary reporting of nanomaterials has had, I’m inclined to agree with the critics. (Thanks to Pasco Phronesis for pointing me to the item.)

If you’ve ever been interested in art restoration (how do they clean and return the colours of an old painting to its original hues?, then the Van Gogh blog is for you. A member of the restoration team is blogging each step of The Bedroom’s (a famous Van Gogh painting) restoration. I was a little surprised that they don’t seem to be using any of the new nano-enabled techniques for examining the painting or doing the restoration work.

Given the name for this website, I have to mention the work done with frogs in pursuit of developing new biofuels by scientists at the University of Cincinnati. From the news item on Nanotechnology Now,

In natural photosynthesis, plants take in solar energy and carbon dioxide and then convert it to oxygen and sugars. The oxygen is released to the air and the sugars are dispersed throughout the plant — like that sweet corn we look for in the summer. Unfortunately, the allocation of light energy into products we use is not as efficient as we would like. Now engineering researchers at the University of Cincinnati are doing something about that.

The researchers are finding ways to take energy from the sun and carbon from the air to create new forms of biofuels, thanks to a semi-tropical frog species [Tungara frog].

Their work focused on making a new artificial photosynthetic material which uses plant, bacterial, frog and fungal enzymes, trapped within a foam housing, to produce sugars from sunlight and carbon dioxide.

Here’s an illustration of the frog by Megan Gundrum, 5th year DAAP student (I tried find out what DAAP stands for but was unsuccessful, ETA: Mar.31.10, it is the Design, art, and architecture program at the University of Cincinnati),

illustration by Megan Gundrum, 5th year DAAP student

Thank you to the University of Cincinnati for making the image available.