Tag Archives: Penn State University

Creating multiferroic material at room temperature

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A Sept. 23, 2016 news item on ScienceDaily describes some research from Cornell University (US),

Multiferroics — materials that exhibit both magnetic and electric order — are of interest for next-generation computing but difficult to create because the conditions conducive to each of those states are usually mutually exclusive. And in most multiferroics found to date, their respective properties emerge only at extremely low temperatures.

Two years ago, researchers in the labs of Darrell Schlom, the Herbert Fisk Johnson Professor of Industrial Chemistry in the Department of Materials Science and Engineering, and Dan Ralph, the F.R. Newman Professor in the College of Arts and Sciences, in collaboration with professor Ramamoorthy Ramesh at UC Berkeley, published a paper announcing a breakthrough in multiferroics involving the only known material in which magnetism can be controlled by applying an electric field at room temperature: the multiferroic bismuth ferrite.

Schlom’s group has partnered with David Muller and Craig Fennie, professors of applied and engineering physics, to take that research a step further: The researchers have combined two non-multiferroic materials, using the best attributes of both to create a new room-temperature multiferroic.

Their paper, “Atomically engineered ferroic layers yield a room-temperature magnetoelectric multiferroic,” was published — along with a companion News & Views piece — Sept. 22 [2016] in Nature. …

A Sept. 22, 2016 Cornell University news release by Tom Fleischman, which originated the news item, details more about the work (Note: A link has been removed),

The group engineered thin films of hexagonal lutetium iron oxide (LuFeO3), a material known to be a robust ferroelectric but not strongly magnetic. The LuFeO3 consists of alternating single monolayers of lutetium oxide and iron oxide, and differs from a strong ferrimagnetic oxide (LuFe2O4), which consists of alternating monolayers of lutetium oxide with double monolayers of iron oxide.

The researchers found, however, that they could combine these two materials at the atomic-scale to create a new compound that was not only multiferroic but had better properties that either of the individual constituents. In particular, they found they need to add just one extra monolayer of iron oxide to every 10 atomic repeats of the LuFeO3 to dramatically change the properties of the system.

That precision engineering was done via molecular-beam epitaxy (MBE), a specialty of the Schlom lab. A technique Schlom likens to “atomic spray painting,” MBE let the researchers design and assemble the two different materials in layers, a single atom at a time.

The combination of the two materials produced a strongly ferrimagnetic layer near room temperature. They then tested the new material at the Lawrence Berkeley National Laboratory (LBNL) Advanced Light Source in collaboration with co-author Ramesh to show that the ferrimagnetic atoms followed the alignment of their ferroelectric neighbors when switched by an electric field.

“It was when our collaborators at LBNL demonstrated electrical control of magnetism in the material that we made that things got super exciting,” Schlom said. “Room-temperature multiferroics are exceedingly rare and only multiferroics that enable electrical control of magnetism are relevant to applications.”

In electronics devices, the advantages of multiferroics include their reversible polarization in response to low-power electric fields – as opposed to heat-generating and power-sapping electrical currents – and their ability to hold their polarized state without the need for continuous power. High-performance memory chips make use of ferroelectric or ferromagnetic materials.

“Our work shows that an entirely different mechanism is active in this new material,” Schlom said, “giving us hope for even better – higher-temperature and stronger – multiferroics for the future.”

Collaborators hailed from the University of Illinois at Urbana-Champaign, the National Institute of Standards and Technology, the University of Michigan and Penn State University.

Here is a link and a citation to the paper and to a companion piece,

Atomically engineered ferroic layers yield a room-temperature magnetoelectric multiferroic by Julia A. Mundy, Charles M. Brooks, Megan E. Holtz, Jarrett A. Moyer, Hena Das, Alejandro F. Rébola, John T. Heron, James D. Clarkson, Steven M. Disseler, Zhiqi Liu, Alan Farhan, Rainer Held, Robert Hovden, Elliot Padgett, Qingyun Mao, Hanjong Paik, Rajiv Misra, Lena F. Kourkoutis, Elke Arenholz, Andreas Scholl, Julie A. Borchers, William D. Ratcliff, Ramamoorthy Ramesh, Craig J. Fennie, Peter Schiffer et al. Nature 537, 523–527 (22 September 2016) doi:10.1038/nature19343 Published online 21 September 2016

Condensed-matter physics: Multitasking materials from atomic templates by Manfred Fiebig. Nature 537, 499–500  (22 September 2016) doi:10.1038/537499a Published online 21 September 2016

Both the paper and its companion piece are behind a paywall.

Inhibiting pathogens in meat with edible antimicrobial films

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Food poisoning is, at best, unpleasant and, at worst, lethal, so anything which helps people and other animals to avoid that condition is to be lauded, assuming there are no significant shortcomings with the solution to avoiding bad meat. According to a May 4, 2014 news item on Nanowerk a team at Penn (Pennsylvania) State University has developed an antimicrobial, edible film which may help solve the problem,

Antimicrobial agents incorporated into edible films applied to foods to seal in flavor, freshness and color can improve the microbiological safety of meats, according to researchers in Penn State’s College of Agricultural Sciences.

Using films made of pullulan — an edible, mostly tasteless, transparent polymer produced by the fungus Aureobasidium pulluns — researchers evaluated the effectiveness of films containing essential oils derived from rosemary, oregano and nanoparticles against foodborne pathogens associated with meat and poultry.

A May 1, 2014 Penn State University news release by Jeff Mulhollem, which originated the news item, describes the research in further detail,

In the study, which was published online in the April issue of the Journal of Food Science, researchers determined survivability of bacterial pathogens after treatment with 2 percent oregano essential oil, 2 percent rosemary essential oil, zinc oxide nanoparticles or silver nanoparticles.

The compounds then were incorporated into edible films made from pullulan, and the researchers determined the antimicrobial activity of these films against bacterial pathogens inoculated onto petri dishes.

Finally, the researchers experimentally inoculated fresh and ready-to-eat meat and poultry products with bacterial pathogens, treated them with the pullulan films containing the essential oils and nanoparticles, vacuum packaged, and then evaluated for bacterial growth following refrigerated storage for up to three weeks.

“The results from this study demonstrated that edible films made frompullulan and incorporated with essential oils or nanoparticles have the potential to improve the safety of refrigerated, fresh or further-processed meat and poultry products,” said Cutter. “The research shows that we can apply these food-grade films and have them do double duty — releasing antimicrobials and imparting characteristics to protect and improve food we eat.”

…

The edible films are a novelbut effective way to deliver antimicrobial agents to meats, Cutter explained, because the bacteria-killing action is longer lasting. Liquid applications run off the surface, are not absorbed and are less effective. The pullulan films adhere to the meat, allowing the incorporated antimicrobials to slowly dissolve, providing immediate and sustained kill of bacteria. In addition, the microorganisms do not have the opportunity to regrow.

There’s at least one problem with the pullulan films and its not, as far as the researcher is concerned, the silver or zinc oxide nanoparticles (from the news release),

Cutter conceded that pullulan films are not as oxygen-impermeable as plastic packaging now used to package meats, so the edible films are not likely to replace that material.

“The meat industry likes the properties of the polyethylene vacuum packaging materials that they are using now,” she said. “However, the one thing I really want to be able to do in the next few years is to figure out a way to co-extrude antimicrobial, edible films with the polyethylene so we have the true oxygen barrier properties of the plastic with the antimicrobial properties of the edible film.”

Knowing that edible films can release antimicrobials slowly over time and keep bacteria in meat at bay, further research will be aimed at creating what Cutter referred to as “active packaging” — polyethylene film with antimicrobial properties.

“Right now, we have two different packaging materials that are not necessarily compatible, leading to a two-step process. I keep thinking there’s a way to extrude edible, antimicrobial film in one layer with polyethylene, creating all-in-one packaging.

“The chemistry of binding the two together is the challenge, but we need to find a way to do it because marrying the two materials together in packaging would make foods — especially meat and poultry — safer to eat.”

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

Incorporation of Essential Oils and Nanoparticles in Pullulan Films to Control Foodborne Pathogens on Meat and Poultry Products by Mohamed K. Morsy, Hassan H. Khalaf, Ashraf M. Sharoba, Hassan H. El-Tanahi and Catherine N. Cutter. Journal of Food Science, April 2014, Volume 79, Issue 4, pages M675–M684. DOI: 10.1111/1750-3841.12400 Article first published online: 12 MAR 2014

© 2014 Institute of Food Technologists®

This is behind a paywall.

Nearby Nature GigaBlitz—Summer Solstice 2012—get your science out

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The June 20 – 26, 2012 GigaBlitz event is an international citizen science project focused on biodiversity. From the June 13, 2012 news item on physorg.com,

A high-resolution image of a palm tree in Brazil, which under close examination shows bees, wasps and flies feasting on nectars and pollens, was the top jury selection among the images captured during last December’s Nearby Nature GigaBlitz. It’s also an example of what organizers hope participants will produce for the next GigaBlitz, June 20-26 [2012].

Here’s a close up from the Brazilian palm tree image,

Bee close up from Palmeira em flor, by Eduardo Frick (http://gigapan.com/gigapans/95168/)

This bee close up does not convey the full impact of an image that you can zoom from a standard size to extreme closeups of insects, other animals, portions of palm fronds, etc. To get the full impact go here.

Here’s more about the Nearby Nature GigaBlitz events from the June 13, 2012 Carnegie Mellon University news release,

The Nearby Nature GigaBlitz events are citizen science projects in which people use gigapixel imagery technology to document biodiversity in their backyards — if not literally in their backyards, then in a nearby woodlot or vacant field. These images are then shared and made available for analysis via the GigaPan website. The events are organized by a trio of biologists and their partners at Carnegie Mellon University’s CREATE Lab.

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December’s GigaBlitz included contributors from the United States, Canada, Spain, Japan, South Africa, Brazil, Singapore, Indonesia and Australia. Ten of the best images are featured in the June issue of GigaPan Magazine, an online publication of CMU’s CREATE Lab.

The issue was guest-edited by the organizers of the GigaBlitz: Ken Tamminga, professor of landscape architecture at Penn State University; Dennis vanEngelsdorp, research scientist at the University of Maryland’s Department of Entomology; and M. Alex Smith, assistant professor of integrative biology at the University of Guelph, Ontario.

The inspiration for the gigablitz comes from the world of ornithology (bird watching), from the Carnegie Mellon University June 13, 2012 news release,

Tamminga, vanEngelsdorp and Smith envisioned something akin to a BioBlitz, an intensive survey of a park or nature preserve that attempts to identify all living species within an area at a given time, and citizen science efforts such as the Audubon Society’s Christmas Bird Count.

“We imagined using these widely separated, but nearby, panoramas as a way of collecting biodiversity data – similar to the Christmas bird count – where citizen scientists surveyed their world, then distributed and shared that data with the world through public GigaPans,” they wrote. “The plus of the GigaPan approach was that the sharing was bi-directional – not merely ‘This is what I saw,’ but also hearing someone say, ‘This is what I found in your GigaPan.'”

Here’s an excerpt from the Nearby Nature gigablitz June 20 -26, 2012 Call for Entries,

The challenge: Gigapixel imaging can reveal a surprising range of animal and plant species in the ordinary and sometimes extraordinary settings in which we live, learn, and work. Your challenge is to capture panoramas of Nearby Nature and share them with your peers at gigapan.org for further exploration. We hope that shared panoramas and snapshotting will help the GigaPan community more deeply explore, document, and celebrate the diversity of life forms in their local habitats.

Gigablitz timing: The event will take place over a 7-day period – a gigablitz – that aligns with the June solstice. Please capture and upload your images to the gigapan.org website between 6am, June 20 and 11pm, June 26 (your local time).

Juried selections:    Panoramas that meet the criteria below are eligible for inclusion in the science.gigapan.org Nearby Nature collection. The best panoramas will be selected by a jury for publication in an issue of GigaPan Magazine dedicated to the Nearby Nature collection.  Selection criteria are as follows:

  • Biodiversity: the image is species rich.
  • Uniqueness: the image contains particularly interesting or unique species, or the image captures a sense of the resilience of life-forms in human-dominated settings.
  • Nearby Nature context: image habitat is part of, or very near, the everyday places that people inhabit.
  • Image quality: the image is of high quality and is visually captivating.

Subjects and locations: The gigablitz subject may be any “nearby” location in which you have a personal interest:  schoolyard garden, backyard habitat, balcony planter, village grove, nearby remnant woods, vacant lot meadow next door and others.  Panoramas with high species richness (the range of different species in a given area) that are part of everyday places are especially encouraged.  It is the process of making and sharing gigapans that will transform the ordinary into the extraordinary.

Here are 3 things to keep in mind when choosing a place:

  • The panorama should focus on organisms in a habitat near your home, school or place of work.
  • Any life-forms are acceptable, such as plants, insects, and other animals.
  • Rich, sharp detail will encourage snapshotters to help identify organisms in your panorama.  Thus, your gigapan unit should be positioned close to the subject habitat – within 100 feet (30 meters) away, and preferably much closer.  Up close mini-habitats in the near-macro range are welcome.

Please do check the Call for Entries for additional information about the submissions.

As for the website which hosts the contest, I checked the About GigaPan page and found this,

What is a GigaPan?

Gigapans are gigapixel panoramas, digital images with billions of pixels. They are huge panoramas with fascinating detail, all captured in the context of a single brilliant photo. Phenomenally large, yet remarkably crisp and vivid, gigapans are available to be explored at GigaPan.com. Zoom in and discover the detail of over 50,000 panoramas from around the world.

A New Dimension for Photography

GigaPan gives experienced and novice photographers the technology to create high-resolution panorama images more easily than ever before, and the resulting GigaPan images offer viewers a new, unique perspective on the world.

GigaPan offers the first solution for shooting, viewing and exploring high-resolution panoramic images in a single system: EPIC series of robotic camera mounts capture photos using almost any digital camera; GigaPan Stitch Software automatically combines the thousands of images taken into a single image; and GigaPan.com enables the unique mega-high resolution viewing experience.

GigaPan EPIC

GigaPan EPIC robotic mounts empower cameras to take hundreds, even thousands of photos, which are combined to create one highly detailed image with amazing depth and clarity.

The GigaPan EPIC and EPIC 100 are compatible with a broad range of point-and-shoot cameras and small DSLRs to capture gigapans, quickly and accurately. Light and compact, they are easy-to-use, and remarkably efficient. The EPIC Pro is designed to work with DSLR cameras and larger lenses, features advanced technology, and delivers stunning performance and precision. Strong enough to hold a camera and lens combination of up to 10 lbs, the EPIC Pro enables users to capture enormous panoramas with crisp, vivid detail.

Bringing Mars Rover Technology to Earth

The GigaPan EPIC series is based on the same technology employed by the Mars Rovers, Spirit and Opportunity, to capture the incredible images of the red planet. Now everyone has the opportunity to use technology developed for Mars to take their own incredible images.

GigaPan was formed in 2008 as a commercial spin-off of a successful research collaboration between a team of researchers at NASA and Carnegie Mellon University. The company’s mission is to bring this powerful, high-resolution imaging capability to a broad audience.

The original GigaPan prototype and related software were devised by a team led by Randy Sargent, a senior systems scientist at Carnegie Mellon West and the NASA Ames Research Center in Moffett Field, Calif., and Illah Nourbakhsh, an associate professor of robotics at Carnegie Mellon in Pittsburgh.

If I understand this rightly, this commercial enterprise (GigaPan), which offers hardware and software,  also supports a community-sharing platform for the types of images made possible by the equipment they sell.

Liquid lenses and integrated research into nanotechnology safety

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A flexible, fluid micro lens has been created by engineers at Penn State University. Here’s why it’s interesting news (from Nanowerk News),

Like tiny Jedi knights, tunable fluidic micro lenses can focus and direct light at will to count cells, evaluate molecules or create on-chip optical tweezers, according to a team of Penn State engineers. They may also provide imaging in medical devices, eliminating the necessity and discomfort of moving the tip of a probe.

For more about the work, go here. On a sidenote, this is the first time I’ve seen a Star Wars metaphor used. Depending on the nature of the breakthrough, you usually get Spiderman, Harry Potter, or Star Trek if they’re using a science fiction metaphor.

In other news, the Institute of Occupational Medicine (IOM) in Scotland will be leading a multi-million Euro project, Engineered NanoParticle Risk Assessment (ENPRA). From Nanowerk News (again),

The 3 ½ year IOM-led project, worth €3.7 million, harnesses the knowledge and capabilities of 15 European and 6 US partners including three US Federal Agencies: EPA, NIOSH and NIH-NIEHS. Under the coordination of Dr Lang Tran, IOM’s Director of Computational Toxicology, ENPRA will utilise the latest advances within in vitro, in vivo and in silico approaches to nanotechnology environment, health & safety (EHS) research to realise its aims.

There’s more about the project here. For anyone not familiar with the US abbreviations, EPA = Environmental Protection Agency, NIOSH = National Institute of Occupational Safety and Health, and NIH-NIEHS = National Institutes of Health – National Institute of Environmental Health and Safety.

I don’t know but this seems like a lot of governments and it could take them years to figure out what the multiple agency abbreviations stand for. Even so, bravo for taking the first steps.