Microwave neural network; electric ice; sputtering ScAlN.
Researchers from Cornell University designed an on-chip microwave neural network that can perform real-time frequency domain computation for tasks like radio signal decoding, radar target tracking, and digital data processing. By using interconnected modes produced in tunable waveguides, the device can handle data streams in the tens of gigahertz while consuming less than 200 milliwatts of power.
“Because it’s able to distort in a programmable way across a wide band of frequencies instantaneously, it can be repurposed for several computing tasks. It bypasses a large number of signal processing steps that digital computers normally have to do,” said Bal Govind, a doctoral student at Cornell, in a press release. “In traditional digital systems, as tasks get more complex, you need more circuitry, more power, and more error correction to maintain accuracy. But with our probabilistic approach, we’re able to maintain high accuracy on both simple and complex computations, without that added overhead.”
The chip achieved at or above 88% accuracy on multiple classification tasks involving wireless signal types, a result comparable to larger, more power-hungry digital neural networks. The researchers expect the chip could excel at hardware security applications like sensing anomalies in wireless communications across multiple bands of microwave frequencies. [1]
Researchers from the Universitat Autónoma de Barcelona, Xi’an Jiaotong University, and Stony Brook University discovered that ice can generate electricity when subjected to irregular mechanical deformation.
“We discovered that ice generates electric charge in response to mechanical stress at all temperatures. In addition, we identified a thin ‘ferroelectric’ layer at the surface at temperatures below -113ºC (160K). This means that the ice surface can develop a natural electric polarization, which can be reversed when an external electric field is applied—similar to how the poles of a magnet can be flipped. The surface ferroelectricity is a cool discovery in its own right, as it means that ice may have not just one way to generate electricity but two: ferroelectricity at very low temperatures, and flexoelectricity at higher temperatures all the way to 0 °C,” said Xin Wen, a member of the ICN2 Oxide Nanophysics Group at UAB, in a statement.
The researchers suggest the discovery could provide new insights into the formation of lightning as well as potentially lead to the development of electronic devices that could be fabricated directly in cold environments and use ice as an active material. [2]
Researchers from the Tokyo University of Science, University of Tokyo, and Sumitomo Electric Industries grew scandium aluminum nitride (ScAlN) thin films on aluminum gallium nitride/gallium nitride (AlGaN/GaN) heterostructures using sputtering to determine key growth conditions. ScAlN has the potential to enhance the performance of GaN HEMTs when used as a barrier material and could serve as a gate material in ferroelectric HEMTs, but growing it typically involves complex techniques and high processing temperatures.
The team used sputtering to epitaxially grow ScAlN films with 10% scandium content at temperatures from 250 °C. Surface flatness of the films improved with increasing temperature to 750 °C, and samples grown at this temperature had three times the carrier density in two-dimensional electron gas compared to AlGaN/AlN/GaN heterostructures without ScAlN. However, the researchers noted that electron mobility was reduced compared to the initial heterostructure, likely due to the roughness and structural imperfections.
“Compared to expensive and complex deposition techniques, sputtering, widely used in electronics manufacturing, can enable the mass production of ScAlN thin films at much lower costs, making high-performance devices more accessible,” said Atsushi Kobayashi, an associate professor in the Department of Materials Science and Technology at TUS, in a statement. “Our study demonstrates the viability of sputtering for growing high-quality ScAlN layers on GaN, offering a practical path towards the commercialization of high-performance GaN HEMTs with ScAlN barriers. This will lead to the widespread use of these transistors, which are fundamental to the development of highly efficient, energy-saving devices that can operate under harsh conditions, including electric vehicles and space vehicles.” [3]
[1] B. Govind, M.G. Anderson, F.O. Wu, et al. An integrated microwave neural network for broadband computation and communication. Nat Electron 8, 738–750 (2025). https://doi.org/10.1038/s41928-025-01422-1
[2] X. Wen, Q. Ma, A. Mannino, et al. Flexoelectricity and surface ferroelectricity of water ice. Nat. Phys. (2025). https://doi.org/10.1038/s41567-025-02995-6
[3] S. Ota, T. Okuda, K. Kubota, et al. Effect of growth temperature on the structural and electrical properties of sputter-epitaxial ScAlN on AlGaN/AlN/GaN heterostructures. APL Mater. 1 August 2025; 13 (8): 081112. https://doi.org/10.1063/5.0281540
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