Tag Archives: polar bears

‘Polar bear wear’: 30% lighter than cotton and much warmer

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For the same reason some people like ‘Christmas in July’ events, I like to occasionally feature a nonseasonal story. Especially since the area where I live is going through an unseasonal cold snap and will be followed shortly by anomalously hot temperatures. So, more or less fittingly, an April 10, 2023 news item announces a new fabric,

Three engineers at the University of Massachusetts Amherst have invented a fabric that concludes the 80-year quest to make a synthetic textile modeled on Polar bear fur. The results, published recently in the journal ACS Applied Materials and Interfaces, are already being developed into commercially available products. [ACS is American Chemical Society.]

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Caption: Inspired by polar bears, this new textile creates an on-body “greenhouse” effect to keep you warm. Credit: Viola et al., 10.1021/acsami.2c23075

Nice to see a properly drawn polar bear. Back to the research, an April 10, 2023 University of Massachusetts Amherst news release (also on EurekAlert), which originated the news item, provides a brief history of the research and a few technical details about the current work, Note: Links have been removed,

Polar bears live in some of the harshest conditions on earth, shrugging off Arctic temperatures as low as -50 Fahrenheit. While the bears have many adaptations that allow them to thrive when the temperature plummets, since the 1940s scientists have focused on one in particular: their fur. How, the scientific community has asked, does a polar bear’s fur keep them warm?

Typically, we think that the way to stay warm is to insulate ourselves from the weather. But there’s another way: One of the major discoveries of the last few decades is that many polar animals actively use the sunlight to maintain their temperature, and polar bear fur is a well-known case in point.

Scientists have known for decades that part of the bears’ secret is their white fur. One might think that black fur would be better at absorbing heat, but it turns out that the polar bears’ fur is extremely effective at transmitting solar radiation toward the bears’ skin.

“But the fur is only half the equation,” says the paper’s senior author,  Trisha L. Andrew, associate professor of chemistry and adjunct in chemical engineering at UMass Amherst. “The other half is the polar bears’ black skin.”

As Andrew explains it, polar bear fur is essentially a natural fiberoptic, conducting sunlight down to the bears’ skin, which absorbs the light, heating the bear. But the fur is also exceptionally good at preventing the now-warmed skin from radiating out all that hard-won warmth. When the sun shines, it’s like having a thick blanket that warms itself up, and then traps that warmth next to your skin.

What Andrew and her team have done is to engineer a bilayer fabric whose top layer is composed of threads that, like polar bear fur, conduct visible light down to the lower layer, which is made of nylon and coated with a dark material called PEDOT [Poly(3,4-ethylenedioxythiophene)]. PEDOT, like the polar bears’ skin, warms efficiently.

So efficiently, in fact, that a jacket made of such material is 30% lighter than the same jacket made of cotton yet will keep you comfortable at temperatures 10 degrees Celsius colder than the cotton jacket could handle, as long as the sun is shining or a room is well lit.

“Space heating consumes huge amounts of energy that is mostly fossil fuel-derived,” says Wesley Viola, the paper’s lead author, who completed his Ph.D. in chemical engineering at UMass and is now at Andrew’s startup, Soliyarn, LLC. “While our textile really shines as outerwear on sunny days, the light-heat trapping structure works efficiently enough to imagine using existing indoor lighting to directly heat the body. By focusing energy resources on the ‘personal climate’ around the body, this approach could be far more sustainable than the status quo.”

The research, which was supported by the National Science Foundation, is already being applied, and  Soliyarn has begun production of the PEDOT-coated cloth.

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

Solar Thermal Textiles for On-Body Radiative Energy Collection Inspired by Polar Animals by Wesley Viola, Peiyao Zhao, and Trisha L. Andrew. ACS Appl. Mater. Interfaces 2023, 15, 15, 19393–19402 DOI: https://doi.org/10.1021/acsami.2c23075 Publication Date: April 5, 2023 Copyright © 2023 American Chemical Society

This paper is behind a paywall.

You can find Soliyarn here.

Want to help Arctic science and look at polar bears from the comfort of home?

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Two polar bears scored according to the Polar Bear Score Card Standard Fatness Index. The bear on the left is categorized as thin, a score of 2/5, while the bear on the right is considered very fat, 5/5. (Photo: Doug Clark, USask

A March 1, 2021 news item on phys.org announced a call for volunteers from University of Saskatchewan (USask) polar bear researcher Doug Clark (the response was tremendous),

University of Saskatchewan (USask) researcher Doug Clark is launching a first-of-its-kind research project that will engage citizen volunteers to help advance knowledge about polar bear behavior by analyzing a decade’s worth of images captured by trail cameras at Wapusk National Park in northern Manitoba.

“This is a totally different way to do polar bear research,” said Clark, an associate professor at USask’s School of Environment and Sustainability. “It’s non-invasive, it involves the public for the first time, and it’s being done in a way that can carry on through the pandemic without endangering anyone in northern communities.”

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A February 26, 2021 University of Saskatchewan news release by Sarath Peiris, which originated the news item, described the project

Clark is collaborating with Oxford University penguinologist Tom Hart on the project, which will be run on Zooniverse—a “people-powered” online platform that has more than two million volunteers worldwide who assist researchers in almost every discipline to sort and organize data.

Hart has been using Zooniverse to help with his Antarctic Penguin Watch and Seabird Watch projects. He’s helping Clark and his students to set up the polar bear project by aggregating and uploading data, and will work with Clark on the analysis. (The platform gets institutional support from Oxford University and the Adler Planetarium, and receives grants from a variety of sources.)

“This allows people, who might otherwise just passively consume images on TV and social media, to participate in polar bear research and understand how these bears are interacting with people and other wildlife in what we know is a rapidly changing environment,” said Clark.

The volunteers are supplied with a field guide and asked to count the number of bears in photos, their gender, cubs, body condition and other factors, choosing from provided options. Beta testing with more than 60 volunteers showed the process works well. The photos will be uploaded in tranches over the coming months, allowing volunteers to work through one batch before moving on to the next.

“Volunteers can help us process data in ways that are incredibly labour-intensive, which otherwise would take us and our students years to do. Frankly, Zooniverse produces more robust data and more robust analyses than if we were tiredly flipping through photos on our own.”

The project … launched Feb. 27 [2021\, on International Polar Bear Day.

The research project began in 2011 when Clark was asked by Parks Canada to find out if the field camps it established in Wapusk attracted or repelled polar bears—a question that still hasn’t been conclusively answered.

Other questions his team is trying to answer are:

  • What are the drivers of polar bear visits to human infrastructure/activity? (i.e. is it environmental, is it a result of a lack of sea ice/nutritional stress, or is it a response to human activity?)
  • Are there changes over time in where/when polar bears, and all the other Arctic and boreal species seen in the photos, are observed?

Researchers have installed five non-invasive trail cameras at each of three field camp sites, and eight more at the Churchill Northern Studies Centre that operate year round, and have captured more than 600 discrete polar bear observations over 10 years, along with images of other species such as wolf, caribou, grizzly bears, moose, Arctic and red foxes, and even occasional wolverines.

The four sites are along the Hudson Bay coast and are separated by almost 200 kilometres, across the ecological boundary between boreal forest and tundra providing invaluable data on multiple species in a changing environment.

Ryan Brook, an associate professor in USask’s College of Agriculture and Bioresources, is taking advantage of the lucky “by-catch” of Clark’s project—the images of caribou and wolves—to conduct research on these species, especially caribou populations, at a time of Arctic warming and changing weather patterns.

Here’s more about the project from The Arctic Bears Project on Zooniverse,

Work with us to understand how polar, grizzly, and black bears behave in a changing environment

About The Arctic Bears Project

We’re learning how polar, grizzly, and black bears behave in the changing Arctic environment, with special attention to how they interact with people. The images you’ll see come from remote cameras set up on the fences of field camps in Wapusk National Park, on the west coast of Hudson Bay in Manitoba, Canada. Wapusk means “white bear” in the Cree language, and the park was established in 1996. At the time the park was established the area was well-known for its importance as polar bear denning habitat, and local people knew black bears lived in the forests there, but the appearance of grizzly bears in the late 1990s was a surprise. Read more about our research findings here.

When we say “we”, that includes a whole lot of people who all contribute to making this project happen: and not just the researchers! Wapusk National Park’s staff in Churchill, Manitoba, got the ball rolling in 2010 and since then community members in Churchill and elsewhere have helped us shape this project. Their enthusiasm for non-invasive wildlife research tools, and for the unexpected things we see on the cameras, motivates our team. In the early days of this work we were just excited that our cameras survived over the winter, but pretty soon we were realizing just how many photos we were collecting. This is where you come in: Zooniverse volunteers. Your help processing a decade’s worth of pictures from a changing sub-Arctic landscape is a critical task, and we’re so grateful to have your assistance with this research. These photos are downloaded once a year from most cameras, and the days when we finally see those images are special treats that every one of our team enjoys. We hope you experience the same feeling.

As of Wednesday, March 3, 2021, The Arctic Bears Project is now out of data but hopefully there will be more in the future. In the meantime, you can check out the Zooniverse for other projects.