Investigating thermal properties of 2D non-layered material using a NEMS-based 2-DOF approach towards ultrahigh-performance bolometer.

Two-dimensional (2D) non-layered materials in many aspects differ from their layered counterparts, and the exploration of their physical properties has produced many intriguing findings. However, due to challenges in applying existing experimental techniques to such nanoscale samples, their thermal properties have remained largely uncharacterized, hindering further exploration and device application using this promising material system. Here, we demonstrate an experimental study of thermal conduction in -InS, a typical non-layered 2D material, using a resonant nanoelectromechanical systems (NEMS) platform.

Identifying, Resolving, and Quantifying Anisotropy in ReS Nanomechanical Resonators.

As an emerging two-dimensional semiconductor, rhenium disulfide (ReS ) is renowned for its strong in-plane anisotropy in electrical, optical, and thermal properties. In contrast to the electrical, optical, optoelectrical, and thermal anisotropies that are extensively studied in ReS , experimental characterization of mechanical properties has largely remained elusive. Here, it is demonstrated that the dynamic response in ReS nanomechanical resonators can be leveraged to unambiguously resolve such disputes.

Electrically Tunable MXene Nanomechanical Resonators Vibrating at Very High Frequencies.

As an emerging class of two-dimensional (2D) layered nanomaterial, MXene exhibits a number of intriguing properties, such as good electrical conductivity and high elastic modulus, and has witnessed continued growth in related device research. However, nanoscale MXene devices which leverage both the intrinsic electrical and mechanical properties of these 2D crystals have not been experimentally studied. Here we demonstrate nanoelectromechanical resonators based on 2D MXene crystals, where TiCT drumheads with a wide range of thickness, from more than 50 layers all the way down to a monolayer, exhibit robust nanomechanical vibrations with fundamental-mode frequency up to >70 MHz in the very high frequency (VHF) band, a displacement noise density down to 52 fm/Hz, and a fundamental-mode frequency-quality factor product up to × ≈ 6.

LiDAR and Deep Learning-Based Standing Tree Detection for Firebreaks Applications.

Forest fire prevention is very important for the protection of the ecological environment, which requires effective prevention and timely suppression. The opening of the firebreaks barrier contributes significantly to forest fire prevention. The development of an artificial intelligence algorithm makes it possible for an intelligent belt opener to create the opening of the firebreak barrier.

Nanomechanical Resonators: Toward Atomic Scale.

The quest for realizing and manipulating ever smaller man-made movable structures and dynamical machines has spurred tremendous endeavors, led to important discoveries, and inspired researchers to venture to previously unexplored grounds. Scientific feats and technological milestones of miniaturization of mechanical structures have been widely accomplished by advances in machining and sculpturing ever shrinking features out of bulk materials such as silicon. With the flourishing multidisciplinary field of low-dimensional nanomaterials, including one-dimensional (1D) nanowires/nanotubes and two-dimensional (2D) atomic layers such as graphene/phosphorene, growing interests and sustained effort have been devoted to creating mechanical devices toward the ultimate limit of miniaturization─genuinely down to the molecular or even atomic scale.

Frequency Scaling, Elastic Transition, and Broad-Range Frequency Tuning in WSe Nanomechanical Resonators.

Nanomechanical resonators based on atomic layers of tungsten diselenide (WSe) offer intriguing prospects for enabling novel sensing and signal processing functions. The frequency scaling law of such resonant devices is critical for designing and realizing these high-frequency circuit components. Here, we elucidate the frequency scaling law for WSe nanomechanical resonators by studying devices of one-, two-, three-, to more than 100-layer thicknesses and different diameters.

Theoretical Investigation of a Highly Sensitive Refractive-Index Sensor Based on TM₀ Waveguide Mode Resonance Excited in an Asymmetric Metal-Cladding Dielectric Waveguide Structure.

This study proposes a highly sensitive refractive-index (RI) sensor based on a TM₀ waveguide mode resonance excited in an asymmetric metal-cladding dielectric waveguide structure, where the analyte serves as the guiding layer. By scanning the wavelength at fixed angles of incidence, the reflection spectra of the sensor were obtained. The results showed that the resonance wavelength redshifted dramatically with increases in the analyte RI, which indicates that this approach can be used to sense both the resonance wavelength and the analyte RI.