MAROKO133 Eksklusif ai: Magnet-controlled soft metamaterial shifts shape, locks form for s

📌 MAROKO133 Hot ai: Magnet-controlled soft metamaterial shifts shape, locks form f

Researchers at Rice University have developed a soft metamaterial that can quickly change size and shape under remote control.

The team says the invention could open the door to safer, more versatile ingestible and implantable medical devices.

Their work, led by Yong Lin Kong, highlights a material that combines unusual flexibility with remarkable strength.

Designed for stability and strength

Metamaterials are engineered structures that gain their properties from geometry rather than chemistry.

The Rice team designed a material that remains stable while also deforming on command, a combination not previously seen in soft structures.

The material withstands compressive loads more than 10 times its weight. It also maintains performance under extreme temperatures and corrosive environments. Such resilience is essential for medical devices that must endure the acidic conditions of the human stomach.

Kong, an assistant professor of mechanical engineering at Rice’s George R. Brown School of Engineering and Computing, said the key was “programmed multistability.”

His group incorporated trapezoidal supports and reinforced beams to lock the structure into shape. “These elements create an energy barrier that locks the structure into its new shape even after the external actuation force is removed,” he said.

Built with microarchitectures

The researchers used 3D-printed molds to construct microarchitectures of tilted beams and supporting segments. This design enables the metamaterial to switch between open and closed states when triggered by a magnetic field.

The transformation holds even after the field is removed, giving the structure a form of memory. The team created larger 3D structures capable of complex movements by linking unit cells as building blocks.

These motions include peristaltic waves, which allow the material to move or deliver fluids in controlled ways.

Kong said this soft approach helps address risks such as ulcers, puncture injuries, and inflammation, which are often linked to rigid devices inside the body.

The team showed that the material continued to function after long exposure to stress and acidic corrosion, conditions similar to those in the gastrointestinal tract.

New frontiers in medical use

The ability to control the metamaterial remotely makes new medical applications possible.

“The metamaterial makes it possible to remotely control the size and shape of devices inside the body,” Kong said.

“This could enable lifesaving capabilities such as precisely controlling where a device stays, delivering medication where it’s needed or applying targeted mechanical forces deep inside the body.”

He added that his group is developing ingestible systems that could one day treat obesity in humans. The same designs may also support therapies for marine mammals.

Rice researchers are working with surgeons at the Texas Medical Center to build wireless fluidic control systems that address unmet clinical needs.

Kong’s first graduate student, Taylor Greenwood, served as the first author of the study and now teaches at Brigham Young University.

Graduate students Brian Elder and Jared Anklam, postdoctoral associates Jian Teng and Saebom Lee, and other collaborators contributed to the research.

Funding came from the National Institutes of Health and the Office of Naval Research.

The study is published in the journal Science Advances.

🔗 Sumber: interestingengineering.com

📌 MAROKO133 Update ai: Thermoelectric material hits record 13% waste heat-to-elect

Researchers have introduced a new material that offers more efficient conversion of waste heat into clean electricity.

Developed by researchers from Queensland University of Technology (QUT), the new material achieves record-high thermoelectric performance.

Scientists added manganese to silver, copper, and telluride to make it the most efficient material of its kind.

Team demonstrated the prototype device

The research team demonstrated the prototype device, which was used to convert electricity.

“We showed it could reach record efficiency levels for its class, and when tested in a prototype device it delivered more than 13 per cent conversion efficiency – putting it alongside the best current technologies,” said first author Dr Nan-Hai Li from the School of Chemistry and Physics.

Researchers revealed that the tiny change to the material resulted in a product far better at converting heat into electricity.

Conversion efficiency

The prototype delivered 13 per cent conversion efficiency, which, in simple terms, meant that with the prototype, for every 100 units of heat energy that went into the device, about 13 units were turned into electricity.

“That might not sound like much, but it is a very high number for thermoelectric materials, with most of them only managing a conversion efficiency of a few per cent,” said Professor Zhi-Gang Chen.

“Every day, huge amounts of heat from cars, factories and power stations simply vanish into the air. This material gives us a way to capture some of that lost energy and turn it into clean power.”

The research pointed to new opportunities for clean energy.

Published in Energy & Environmental Science, the study achieved a high dimensionless figure of merit (ZT) of ∼1.88 at 773 K in p-type manganese-doped polycrystalline AgCuTe, which is one of the highest reported values for AgCuTe-based materials and is comparable to other state-of-the-art medium-temperature thermoelectrics.

This enhancement stems from band convergence and valence band flattening without compromising the intrinsically low thermal conductivity, as per the study.

Manganese doping effectively optimizes the electronic band structure

The research team revealed that manganese doping effectively optimizes the electronic band structure to improve the power factor and simultaneously reduces lattice thermal conductivity through intensified lattice defects.

“Every day, huge amounts of heat from cars, factories and power stations simply vanish into the air. This material gives us a way to capture some of that lost energy and turn it into clean power,” said Chen.

“Unlike many other options, this compound doesn’t rely on toxic elements. It’s stable, simple to produce, and therefore a strong candidate for real-world use,” said Dr Xiao-Lei Shi from QUT’s School of Chemistry and Physics.

The system yields superior thermoelectric performance and higher average ZT values than previously reported p-type AgCuTe materials.

Researchers revealed that their work highlights the effectiveness of electronic band structure engineering in enhancing the thermoelectric performance of superionic conductors.

🔗 Sumber: interestingengineering.com