Story tips from the Department of Energy’s Oak Ridge National Laboratory, December 2022

Naturally derived materials fit for 3D printing; Next-gen hydropower starts with testing; Long-haul trucking meets megawatt-scale charging; New insights advance atomic-scale manufacturing

Peer-Reviewed Publication

DOE/OAK RIDGE NATIONAL LABORATORY

 

IMAGE: RESEARCHERS FOUND THAT MODERATE LEVELS OF ASH — SOMETIMES FOUND AS SPHERES IN BIOMASS — DO NOT SIGNIFICANTLY AFFECT THE MECHANICAL PROPERTIES OF BIOCOMPOSITES MADE UP OF CORN STOVER, SWITCHGRASS AND PLA THERMOPLASTIC. view more 

CREDIT: ANDY SPROLES/ORNL, U.S. DEPT. OF ENERGY

Naturally derived materials fit for 3D printing

Biocomposites comprising corn stover, switchgrass prove their mettle

The presence of minerals called ash in plants makes little difference to the fitness of new naturally derived compound materials designed for additive manufacturing, an Oak Ridge National Laboratory-led team found.

When mixed with polylactic acid, fibers sourced from corn stover and switchgrass yielded biocomposites with satisfactory properties for 3D printing. In fact, the presence of ash spheres appeared to improve the flow of material for extrusion printing, said ORNL’s Xianhui Zhao.

“We went as high as 12% ash content on our corn stover biocomposite and found mechanical properties like stress and strain tolerance and tensile strength to be acceptable,” Zhao said.

The research enables a use for high-ash biomass residue from biorefining that could lower the overall cost of producing sustainable fuels and materials.

Next steps include exploring more biomass materials and testing the composites in a large-volume printer at ORNL. — Stephanie Seay

Technology to retrofit nonpowered dams such as the Lake Sequoyah Dam in North Carolina could be tested before deployment to ensure performance and reliability.

CREDIT

Scott DeNeale/ORNL, U.S. Dept. of Energy

Next-gen hydropower starts with testing

National full-scale test facilities could spur adoption of new clean energy technologies

Researchers at Oak Ridge National Laboratory have identified a key need for future hydropower innovations – full-scale testing – to better inform developers and operators before making major investments.

In a new report, ORNL outlines the benefits of establishing a network of national hydropower testing facilities to demonstrate new clean energy technologies and encourage early adoption.

To meet the growing demand for sustainable and renewable energy, existing hydropower facilities are investing in more flexible powertrains, expanding storage capabilities and improving their environmental footprint. New small hydropower development, such as retrofits of nonpowered dams, also aims to reduce costs through advanced manufacturing methods and innovative designs. These new technologies must be proven to first adopters, and testing at relevant scale is a critical step.

“Accessible testing would encourage operators to deploy water power technologies and fuel new research,” said ORNL’s Mirko Musa. “A national testing facility can provide validation or a safe place to fail, accelerating innovation and adoption.” — Mimi McHale

CAPTION

A multiport design allows a utility to easily interface with an EV truck stop to provide fast charging at megawatt scale.

CREDIT

Andy Sproles/ORNL, U.S. Dept. of Energy

Long-haul trucking meets megawatt-scale charging

Future EV truck stop designed to smooth high demand on electric grid

Transitioning long-haul trucks from diesel to electric power will require convenient ways to rapidly recharge electric vehicle batteries at power-plant scale. Researchers at Oak Ridge National Laboratory have designed architecture, software and control strategies for a futuristic EV truck stop that can draw megawatts of power and reduce carbon emissions.

The station’s design uses solar arrays and batteries, which generate and store enough power to handle the unpredictable load swings from recharging these large power plants on wheels. The software manages the system to draw a steady, predictable flow of power from the grid. The team fine-tuned the complex control hierarchy using real-time simulation, then verified those results with electronics in the lab.

“The next phase is looking at how to coordinate multiple stations in a network along the interstate,” said ORNL’s Radha Krishna Moorthy. Paired with advances in low- and zero-carbon fuels, electrification can help reduce the trucking industry’s carbon footprint.

When an electron beam drills holes in heated graphene, single-atom vacancies, shown in purple, diffuse until they join with other vacancies to form stationary structures and chains, shown in blue.

CREDIT

Ondrej Dyck/ORNL, U.S. Dept. of Energy

New insights advance atomic-scale manufacturing

Graphene’s unexpected resilience at higher temperatures results when single-atom vacancies roam

Oak Ridge National Laboratory researchers serendipitously discovered when they automated the beam of an electron microscope to precisely drill holes in the atomically thin lattice of graphene, the drilled holes closed up. They expected the heat to make atoms easier to remove, but they saw the opposite effect.

“Graphene appeared impervious to the electron beam,” said Ondrej Dyck, who co-led the study with Stephen Jesse at ORNL’s Center for Nanophase Materials Sciences. Jesse added, “It heals locally, like the (fictitious) liquid-metal T-1000 in the movie Terminator 2: Judgment Day.”

Theory-based computations performed on the lab’s Summit supercomputer, led by ORNL’s Mina Yoon, explained the quasi-metal’s healing ability: Single atomic vacancies zip through the heated graphene until they meet up with other vacancies and become immobilized.

“Similar processes are likely to extend to other 2D materials,” Dyck said.

“Controlling such processes could help us realize graphene’s promise for quantum information science,” said Jesse.

The researchers are applying this new knowledge to guide creation of atomic-scale devices.

Media contact: Dawn Levy, 865.202.9465, levyd@ornl.gov

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JOURNAL

Composites