By manipulating atomic disorder, entropy engineering is transforming how we create materials for future technologies.
In entropy engineering, scientists cleverly control or utilize disorder (entropy) to improve material performance. This means creating materials with the right balance of order and disorder to function optimally.
entropy, the measure of a system’s thermal energy per unit temperature that is unavailable for doing useful work
To illustrate, think of a tidy, organized room with low entropy. In contrast, a messy room has high entropy. Essentially, entropy measures the degree of disorder in a system. In science, the concept is often applied to discussions about energy and heat.
Entropy manipulation for better performance
Entropy engineering has shown promise in improving various material properties, such as thermoelectric efficiency.
For example, by introducing different types of atoms into a material, scientists can create a controlled amount of disorder (high entropy) that helps disperse heat-transferring particles while allowing electrical currents to flow.
This means the material can prevent heat movement while maintaining good electrical conductivity. Semi-Heusler alloys are an example of this principle in action. These metal mixtures, optimized by adding extra metals, exhibit high entropy that blocks heat transfer and enhances their ability to generate electricity from heat.
Entropy engineering also plays a role in understanding biological systems, such as protein folding—a key challenge in molecular biology and biophysics. Proteins transition from a chaotic, unfolded state (high entropy) to a stable, functional structure (low entropy).
The energy released during bond formation balances the decrease in entropy, stabilizing the protein. Misfolding can lead to diseases like Alzheimer’s, making research in this area crucial for developing better therapies.
Why promising high-entropy materials remain in the lab
Despite significant advancements, high-entropy materials face challenges in large-scale practical applications. A 2022 study led by Shifeng Zhou at the State Key Laboratory of Luminescent Materials and Devices highlighted the need to move beyond traditional material design principles, which focus primarily on enthalpy (energy content).
Conventional material design typically relies on a principle where one or two main ingredients form the foundation, with minor elements serving as supplementary components.
This approach inherently limits the scope of material innovation. As noted, “entropy engineering” introduces a paradigm shift: when the number of principal components surpasses a certain threshold, the structural evolution during material preparation becomes driven by entropic characteristics. In this scenario, materials avoid forming intercomponent compounds and instead develop into a single phase.
The study highlights that advancements in high-entropy alloys and ceramic materials have significantly broadened their applications.
However, is this approach cost-effective? “Although high-entropy materials have excellent material properties and theoretically hold significant value in multiple fields, current research on high-entropy materials is still primarily concentrated in laboratories. Due to limitations such as manufacturing cost and yield, high-entropy materials have not yet achieved large-scale application in practical engineering,” the researcher told Interesting Engineering.
He further emphasized that many countries now classify high-entropy materials as strategic resources.
New high-entropy materials push energy conversion boundaries
A 2022 study introduced the first quantum-confined high-entropy nanoparticles, unlocking new classes of nanomaterials for photonics, optoelectronics, photocatalysis, and thermoelectric energy conversion.
David Lewis, Head of the Department of Materials at the University of Manchester, highlighted their potential for energy-generating devices like solar cells and thermoelectrics.
“We recently reported the synthesis for the first time of a high entropy chalcogenide as a thin film. We are quite excited about this because this is the functional form taken for many energy-generating devices e.g. solar cells / thin-film thermoelectrics,” Lewis told IE.
The study developed high-entropy thin films with diverse metallic compositions, demonstrating versatility in catalytic and energy-related applications.
When asked about the effectiveness of entropy engineering and strategies to optimize materials for energy conversion and sustainability, Lewis highlighted numerous opportunities in sustainable energy production.
These include applications in thermoelectricity, electrocatalysis, batteries, energy storage, and elastic ceramics. He added that the list of novel and unexpected uses for these materials continues to expand daily.
Thermoelectric generators convert waste heat into electricity, making them useful for recovering energy from heat-producing machines. A study published in September 2024 revealed that these devices could soon rival other renewable energy sources in efficiency.
By leveraging high-entropy materials, researchers developed thermoelectric materials capable of achieving conversion efficiencies of up to 15 percent, a significant improvement over the current five to six percent. These advancements hold great potential for utilizing waste heat in industries and applications like space missions.
Future frontiers
Zhou explained that entropy engineering can be limited to crystalline alloys and ceramic materials. Advancing entropy engineering requires extending its principles to amorphous materials, such as photonic glass, and developing efficient methods for predicting material properties.
Theoretical simulations, artificial intelligence, and similar tools can identify the optimal components for high-performance materials, significantly shortening the research and development cycle. However, the relatively high material preparation cost remains a barrier to practical engineering applications.
To overcome this, innovative applications must drive the creation of new material requirements, guiding the engineering use of high-entropy materials and unlocking their full potential.
According to a market survey by Business Research, the global high-entropy alloy market is expected to grow from USD 54.7 million in 2022 to USD 486 million by 2032. This growth underscores the transformative potential of high-entropy materials in revolutionizing materials science and engineering.
High-entropy materials offer a new paradigm in material science by sustainably controlling chaos. From improving thermoelectric efficiency to pioneering applications in nanotechnology and biological systems, entropy engineering holds the key to unlocking innovative solutions for the future.
Source: IE
