We present an optomechanical device platform for characterization of rheological, optical and thermal properties of fluids on the micron scale. A suspended silicon microdisk resonator with a vibrating mass of 100 pg and an effective probing volume of less than a pL is used to monitor properties of different fluids at rest. By employing analytical models for fluid-structure interactions, thermo-optical effects and thermal diffusion, our platform determines the viscosity, density, compressibility, refractive index and thermal conductivity of the fluid, in a compact measurement setup. A single measurement takes as short as 70 μs, and the employed power can be less than 100 μW, guaranteeing measurement at rest and in thermal equilibrium.
We derive closed-form upper bounds on the power deliverable by Electrodynamic Wireless Power Transfer (EWPT) receivers using the near-limit methodology, originally developed for kinetic energy harvesters. By identifying the optimal trajectory of the receiver mass that maximizes energy transfer, we obtain the upper power bounds for various types of EWPT receivers. The results cover translational and rotational EWPT receivers under unidirectional and rotating magnetic fields and yield a global power bound set by the magnetic-field frequency and amplitude and the magnet volume. The bounds reveal simple scaling laws: the power density ceiling grows linearly with frequency and with field amplitude. From these bounds, we define a physically grounded figure of merit (FoM) enabling fair comparisons across receiver types. Measured prototypes from the literature lie below the predicted ceilings, quantifying headroom for future EWPT designs.
In this article, we present a new modeling approach to analyze the effect of pulsed stress frequency on the time to breakdown of high- $K$ metal gates in CMOS transistor devices. First, we compare DC time-dependent dielectric breakdown (TDDB) and AC TDDB results obtained from samples fabricated using 28 nm FDSOI technology from STMicroelectronics. Then, we review the possible hypotheses that could explain the improvement in gate dielectric time to breakdown under pulsed stress. We provide details of a trapping-based TDDB model and compare the modeled effects of stress frequency on key TDDB parameters, such as median time to breakdown and voltage acceleration exponent, with experimental results. Finally, we apply the model findings to digital and RF circuit test cases to investigate the impact of frequency effects on product reliability margins.
Hybrid beamforming for massive MIMO in FR3 is a key enabler for future 6G systems, offering a favorable tradeoff between performance and hardware complexity. In subarraybased hybrid architectures, the large antenna array is partitioned into multiple subarrays, each driven by a reduced number of RF chains, significantly lowering cost and power consumption. This article investigates how to efficiently dimension an over-the-air (OTA) testbed to synthesize realistic spatial correlation across the full array or selected subarrays under different channel models. Various optimization methods and probe configurations are analyzed to provide insights into practical OTA testbed design for FR3 massive MIMO systems.
The semantic and goal-oriented communication paradigm is a fundamental shift in the design of next-generation 6G networks, aiming to support an increasingly connected, intelligent, and sustainable digital ecosystem. This paper provides a comprehensive overview of the architecture and operational framework developed within the 6G-GOALS project, with particular emphasis on its core design pillars: ultra-low latency, semantic communications, AI-native integration, energy efficiency, and enhanced network resilience. The paper details the novel architectural components of the 6G-GOALS framework, which builds on and extends the O-RAN architecture by integrating semantic-aware entities and protocols. Key enablers, including distributed AI, real-time, goal-driven decision-making, and adaptive orchestration of network functions, are presented, illustrating how these capabilities work in concert to realize fully semantic-aware, intelligent, and self-adaptive network operations capable of meeting the demands of next-generation connectivity. Finally, we provide an evaluation of the architecture’s potential to meet key performance indicators (KPIs), its alignment with sustainability goals, and its readiness for the evolving digital ecosystem. This analysis is intended to serve as a foundational reference for researchers and industry stakeholders working to advance the 6G vision.
