Hungarian Researchers Discover New State of Matter
-
Loading... - Benedikt Pavlov
- 11 Feb 2025
- 46 Views
- 0 Like
- 0 Comment
Researchers at the HUN-REN Wigner Research Centre for Physics have made a groundbreaking discovery of a new state of matter, where liquid droplets behave like actively moving, interacting particles when influenced by an electric field. This finding could pave the way for advancements in precision technology.
The team, led by Péter Salamon and Marcell Tibor Máthé, has been investigating a special type of liquid known as ferroelectric nematic liquid crystals. These materials consist of elongated, asymmetric molecules that are highly polar, meaning they possess opposite electrical charges at each end. The unique aspect of ferroelectric nematic liquids is that their molecular arrangement does not cancel out individual charge distributions; instead, the polarizations accumulate, resulting in spontaneous electric polarization.
Although the existence of ferroelectric nematic liquids was predicted over a century ago, they were first synthesized in 2017. The researchers observed that when a higher voltage was applied to the liquid droplets, they lost their droplet shape and formed complex, maze-like structures. Additionally, when an alternating voltage was applied within a specific frequency range, the droplets began to move and change shape, repelling and colliding with each other like active particles, reminiscent of swarming insects or microrobots.
The ability to control the motion of these droplets using voltage suggests potential applications in microfluidic devices, which could benefit fields such as medical diagnostics, chemical analysis, and biotechnology. Interestingly, the researchers also noted that this movement was accompanied by sound emissions, which were analyzed spectrally. The sound indicated that the droplets underwent mechanical vibrations when exposed to alternating voltage, with frequencies corresponding to the driving signal and its second harmonic.
In collaboration with Professor Antal Jákli from Kent State University, the researchers demonstrated the phenomenon of inverse piezoelectricity in three-dimensional liquids for the first time. This effect means that applying voltage to a ferroelectric nematic liquid causes mechanical displacement proportional to the voltage. Conversely, mechanical deformation generates electrical charges on the material's surface. The piezoelectric coupling constant of the studied material exceeds 1 nC/N in the kHz frequency range, indicating that a force of one newton generates at least one nanocoulomb of charge. This exceptional property is comparable to the strongest piezoelectric solid materials, showcasing the remarkable capabilities of this liquid state.
Understanding the electromechanical response of ferroelectric nematic liquid crystals opens up possibilities for harvesting mechanical energy and developing liquid actuators, micro-positioners, and electrically tunable optical lenses. The researchers published their findings in the prestigious journal Nature Communications and Advanced Functional Materials.
The HUN-REN organization aims to become a leading research institution in Europe, contributing significantly to Hungary’s social and economic success. The HUN-REN Act, effective from January 1, 2025, will provide a framework for transforming the organization into a more responsive and collaborative entity, ensuring the freedom of scientific research and fostering multidisciplinary solutions to complex challenges.
This discovery of a new state of matter by Hungarian researchers not only enhances our understanding of ferroelectric nematic liquids but also holds promise for innovative applications in various technological fields. As HUN-REN continues to advance its research capabilities, it positions itself as a key player in the European scientific community.
