Nanomechanical Resonators: Toward Atomic Scale

Abstract

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 new 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 onedimensional (1D) nanowires/nanotubes, and two-dimensional (2D) atomic layers such as graphene/phosphorene, growing interests and sustained efforts have been devoted to creating mechanical devices toward the ultimate limit of miniaturization-genuinely down to the molecular or even atomic scale. These ultrasmall movable structures, particularly nanomechanical resonators that exploit the vibratory motion in these 1D and 2D nano-toatomic-scale structures, offer exceptional device-level attributes, such as ultralow mass, ultrawide frequency tuning range, broad dynamic range, and ultralow power consumption, thus holding strong promises for both fundamental studies and engineering applications. In this Review, we offer a comprehensive overview and summary of this vibrant field, present the state-of-the-art devices and evaluate their specifications and performance, outline important achievements, and postulate future directions for studying these miniscule yet intriguing molecular-scale machines.

Electrically Tunable MXene Nanomechanical Resonators Vibrating at Very High Frequencies

“…Here we demonstrate nanoelectromechanical system (NEMS) resonators based on 2D Ti 3 C 2 T x crystals with resonance reaching the very high frequency (VHF) bands, displacement noise down to 52 fm/Hz 1/2 , and a fundamental-mode frequency-quality factor product f 0 × Q up to 6.85 × 10 9 Hz, a figure of merit that rivals or even surpasses values in many graphene NEMS resonators. − We further elucidate frequency scaling law in 2D MXene resonators by measuring devices of a wide range of thickness from more than 50 layers all the way down to a monolayer, which reveals important design guidelines for future MXene devices toward microwave frequencies. By combining experimental results with theoretical calculations, we independently derive the Young’s modulus of 2D Ti 3 C 2 T x crystals to be 270–360 GPa, in excellent agreement with nanoindentation measurements, and device pretension levels of 0.05–0.5 N/m, highly consistent with other 2D NEMS resonators .…”

“…Here we demonstrate nanoelectromechanical system (NEMS) resonators 36 based on 2D Ti 3 C 2 T x crystals with resonance reaching the very high frequency (VHF) bands, displacement noise down to 52 fm/Hz 1/2 , and a fundamentalmode frequency-quality factor product f 0 × Q up to 6.85 × 10 9 Hz, a figure of merit that rivals or even surpasses values in many graphene NEMS resonators. 37−40 We further elucidate frequency scaling law in 2D MXene resonators by measuring devices of a wide range of thickness from more than 50 layers all the way down to a monolayer, which reveals important design guidelines for future MXene devices toward microwave frequencies.…”

Nonlinear Stiffness and Nonlinear Damping in Atomically Thin MoS2 Nanomechanical Resonators

“…Miniaturized nonlinear resonators, particularly those made in micro/nanoelectromechanical systems (M/NEMS), have received growing interest in recent years because of their small sizes and related advantages, including their nimble tunability, which opens the door to novel applications. , Nonlinearity plays an increasingly important role in describing the dynamic behavior of these devices, − due to their relatively small sizes and high vibration amplitudes. This has an impact on the performance of such resonators, for example, in engineering the quantum behavior of M/NEMS, force and mass sensing, and radio frequency (RF) signal processing applications. − These applications require very high precision, which necessitates performance improvements associated with high quality ( Q ) factors, large signal-to-noise ratio, very low phase noise, etc. To meet these demands, M/NEMS resonators are frequently operated at relatively large vibration amplitudes that can induce the onset of nonlinearity.…”

Protein adsorption by nanomechanical mass spectrometry: Beyond the real-time molecular weighting

“…The earlier studies on NR-based mass spectrometry have aimed to reach sensitivity comparable to that of commercial MS. We remind the reader that the achievable sensitivity of the NR depends on the resonant frequencies; that is, the higher operating frequencies of the NR yield the higher mass sensitivity ( Ekinci et al, 2004 ; Gruber et al, 2019 ). To date, the most promising strategies to achieve the ultra-high operating resonant frequencies and, correspondingly, to enhance the mass sensitivity include the miniaturization of NRs ( Yang et al, 2006 ; Xu et al, 2022 ), detection of the higher vibrational modes ( Dohn et al, 2005 ; Ghatkesar et al, 2007 ) or, more recently, the non-linear oscillations ( Yuksel et al, 2019 ; Lyu et al, 2020 ). It is noteworthy that during the past decade, the superb, that is, a Dalton, mass sensitivity has been experimentally demonstrated by using the one-dimensional carbon nanotube-based NR ( Chaste et al, 2012 ), while in the same period of time the mass spectrometry community were trying to improve the capability of the conventional MS for measurement of larger (>MDa) masses including the protein complexes ( Snijder et al, 2013 ).…”