Nav: Home

Durable wood 'sponges' act as green sensors of mechanical strain

March 01, 2018

Striking just the right balance between softness and sturdiness, balsa wood is a choice material for crafting anything from model airplanes to full-size wind turbine blades. Scientists in the United States and China have opened up a new realm of possibilities for balsa by hijacking its natural structure with chemical and physical treatments to transform it into a "wood carbon sponge" capable of enduring repeated compression and other extreme mechanical conditions. Their work appears March 1 in the journal Chem.

"Our results reveal that rigid and incompressible balsa can be made highly compressible by a chemical treatment and carbonization process, yielding a wood carbon sponge with mechanical compressibility and fatigue resistance and electrical response sensitivity surpassing those of most reported compressible carbonaceous materials," says co-senior author Liangbing Hu, a nano-engineer and materials scientist at the University of Maryland, College Park (UMD)'s A. James Clark School of Engineering. "Since this wood carbon sponge is fabricated completely from natural wood with a simple and cost-effective method, the source material is also exceptionally renewable and sustainable, as opposed to popular options like carbon nanotubes or graphene."

The authors achieved the bendable yet resilient architecture of the wood carbon sponge by using common chemicals to destroy the stiff hemicellulose and lignin fibers that maintain the normal cell-wall structure of the balsa wood and then heating the treated wood to 1,000?C in order to turn the organic material into carbon alone. The net effect of the process was to collapse the repeated, regular, rectangular pockets typical of the microstructure of balsa and other woods and replace them with a stack of wavy, interlocking, arch-like carbon sheets, likened by Hu to a cross between a coiled spring and a honeycomb.

Whereas normal carbonized wood, obtained from only the heating step without any chemical modifications, is so fragile that any reasonable applied force pulverizes it irreversibly into ash and dust, the wood carbon sponge withstood and rebounded from substantial compression for up to 10,000 consecutive trials before deformation set in. Such a performance initially surprised the research team, which was also headed by Teng Li, a mechanical engineer at the University of Maryland, College Park, and Jia Xie, an electrical engineer at the Huazhong University of Science and Technology (China).

After conducting further mechanical and electrical tests on the sponge, the researchers were able to incorporate a slice of it into a strain sensor prototype suitable for attachment to a human finger, a quality desirable for use in wearable fitness or health-monitoring electronics.

The researchers believe that the wood carbon sponge material could also be incorporated into water-purification devices and energy storage and conversation technologies, such as supercapacitors and rechargeable batteries. "The abundant applications illustrate the value of a strategy that explores the hidden potentials of natural materials, such as trees, by drawing inspiration from other natural structures and sources," Hu says.
-end-
This work was supported by the Maryland NanoCenter.

Chem, Chen et al.: "Scalable and sustainable approach toward highly compressible, anisotropic, lamellar carbon sponge" http://www.cell.com/chem/fulltext/S2451-9294(17)30530-2

Chem (@Chem_CP) is the first physical science journal published by Cell Press. A sister journal to Cell, Chem, which is published monthly, provides a home for seminal and insightful research and showcases how fundamental studies in chemistry and its sub-disciplines may help in finding potential solutions to the global challenges of tomorrow. Visit: http://www.cell.com/chem. To receive Cell Press media alerts, contact press@cell.com.

Cell Press

Related Carbon Articles:

Can wood construction transform cities from carbon source to carbon vault?
A new study by researchers and architects at Yale and the Potsdam Institute for Climate Impact Research predicts that a transition to timber-based wood products in the construction of new housing, buildings, and infrastructure would not only offset enormous amounts of carbon emissions related to concrete and steel production -- it could turn the world's cities into a vast carbon sink.
Investigation of oceanic 'black carbon' uncovers mystery in global carbon cycle
An unexpected finding published today in Nature Communications challenges a long-held assumption about the origin of oceanic black coal, and introduces a tantalizing new mystery: If oceanic black carbon is significantly different from the black carbon found in rivers, where did it come from?
First fully rechargeable carbon dioxide battery with carbon neutrality
Researchers at the University of Illinois at Chicago are the first to show that lithium-carbon dioxide batteries can be designed to operate in a fully rechargeable manner, and they have successfully tested a lithium-carbon dioxide battery prototype running up to 500 consecutive cycles of charge/recharge processes.
How and when was carbon distributed in the Earth?
A magma ocean existing during the core formation is thought to have been highly depleted in carbon due to its high-siderophile (iron loving) behavior.
New route to carbon-neutral fuels from carbon dioxide discovered by Stanford-DTU team
A new way to convert carbon dioxide into the building block for sustainable liquid fuels was very efficient in tests and did not have the reaction that destroys the conventional device.
How much carbon the land can stomach with more carbon dioxide in the air
Researchers from 28 institutions in nine countries succeeded in quantifying carbon dioxide fertilization for the past five decades, using simulations from 12 terrestrial ecosystem models and observations from seven field carbon dioxide enrichment experiments.
'Charismatic carbon'
According to the Intergovernmental Panel on Climate Change (IPCC), addressing carbon emissions from our food sector is absolutely essential to combatting climate change.
Extreme wildfires threaten to turn boreal forests from carbon sinks to carbon sources
A research team investigated the impact of extreme fires on previously intact carbon stores by studying the soil and vegetation of the boreal forest and how they changed after a record-setting fire season in the Northwest Territories in 2014.
Can we still have fun if the UK goes carbon neutral?
Will Britain going carbon neutral mean no more fun? Experts from the University of Surrey have urged local policy makers to put in place infrastructure that will enable people to enjoy recreation and leisure while keeping their carbon footprint down.
Could there be life without carbon? (video)
One element is the backbone of all forms of life we've ever discovered on Earth: carbon.
More Carbon News and Carbon Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Dispatch 3: Shared Immunity
More than a million people have caught Covid-19, and tens of thousands have died. But thousands more have survived and recovered. A week or so ago (aka, what feels like ten years in corona time) producer Molly Webster learned that many of those survivors possess a kind of superpower: antibodies trained to fight the virus. Not only that, they might be able to pass this power on to the people who are sick with corona, and still in the fight. Today we have the story of an experimental treatment that's popping up all over the country: convalescent plasma transfusion, a century-old procedure that some say may become one of our best weapons against this devastating, new disease.   If you have recovered from Covid-19 and want to donate plasma, national and local donation registries are gearing up to collect blood.  To sign up with the American Red Cross, a national organization that works in local communities, head here.  To find out more about the The National COVID-19 Convalescent Plasma Project, which we spoke about in our episode, including information on clinical trials or plasma donation projects in your community, go here.  And if you are in the greater New York City area, and want to donate convalescent plasma, head over to the New York Blood Center to sign up. Or, register with specific NYC hospitals here.   If you are sick with Covid-19, and are interested in participating in a clinical trial, or are looking for a plasma donor match, check in with your local hospital, university, or blood center for more; you can also find more information on trials at The National COVID-19 Convalescent Plasma Project. And lastly, Tatiana Prowell's tweet that tipped us off is here. This episode was reported by Molly Webster and produced by Pat Walters. Special thanks to Drs. Evan Bloch and Tim Byun, as well as the Albert Einstein College of Medicine.  Support Radiolab today at Radiolab.org/donate.