Hybrid Shape Memory Alloy-Based Nanomechanical Resonators for Ultrathin Film Elastic Properties Determination and Heavy Mass Spectrometry

Abstract

Micro-/nanomechanical resonators are often used in material science to measure the elastic properties of ultrathin films or mass spectrometry to estimate the mass of various chemical and biological molecules. Measurements with these sensors utilize changes in the resonant frequency of the resonator exposed to an investigated quantity. Their sensitivities are, therefore, determined by the resonant frequency. The higher resonant frequency and, correspondingly, higher quality factor (Q-factor) yield higher sensitivity. In solution, the resonant frequency (Q-factor) decreases causing a significant lowering of the achievable sensitivity. Hence, the nanomechanical resonator-based sensors mainly operate in a vacuum. Identification by nanomechanical resonator also requires an additional reference measurement on the identical unloaded resonator making experiments, due to limiting achievable accuracies in current nanofabrication processes, yet challenging. In addition, the mass spectrometry by nanomechanical resonator can be routinely performed for light analytes (i.e., analyte is modelled as a point particle). For heavy analytes such as bacteria clumps neglecting their stiffness result in a significant underestimation of determined mass values. In this work, we demonstrate the extraordinary capability of hybrid shape memory alloy (SMA)-based nanomechanical resonators to i) notably tune the resonant frequencies and improve Q-factor of the resonator immersed in fluid, ii) determine the Young’s (shear) modulus of prepared ultrathin film only from frequency response of the resonator with sputtered film, and iii) perform heavy analyte mass spectrometry by monitoring shift in frequency of just a single vibrational mode. The procedures required to estimate the Young’s (shear) modulus of ultrathin film and the heavy analyte mass from observed changes in the resonant frequency caused by a phase transformation in SMA are developed and, afterward, validated using numerical simulations. The present results demonstrate the outstanding potential and capability of high frequency operating hybrid SMA-based nanomechanical resonators in sensing applications that can be rarely achieved by current nanomechanical resonator-based sensors.

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

“…Interestingly, recent studies have shown that NRs hold promise in the identification of even the larger masses (>GDa) (Dominguez-Medina et al, 2018;Stachiv and Gan., 2019;Stachiv et al, 2020;Erdogan et al, 2022). Moreover, there is a consensus among researchers that in order to gain more necessary information on the protein adsorption beyond its mass and position of attachment, a symbiosis of experiments with advanced theoretical modeling would be needed (Malvar et al, 2016;Stassi et al, 2019).…”

“…Hence, there is an ongoing dispute on the application limits of the NRs, especially the multimode method, in the identification and analysis of a single or multiple protein(s) adsorbed on the resonator surface ( Tamayo et al, 2013 ). Interestingly, recent studies have shown that NRs hold promise in the identification of even the larger masses (>GDa) ( Dominguez-Medina et al, 2018 ; Stachiv and Gan., 2019 ; Stachiv et al, 2020 ; Erdogan et al, 2022 ). Moreover, there is a consensus among researchers that in order to gain more necessary information on the protein adsorption beyond its mass and position of attachment, a symbiosis of experiments with advanced theoretical modeling would be needed ( Malvar et al, 2016 ; Stassi et al, 2019 ).…”

Anti-Symmetric Mode Vibration of Electrostatically Actuated Clamped–Clamped Microbeams for Mass Sensing

“…Due to their great potential and unique characteristics, microbeam resonant sensors have the advantages of small, fast, high sensitivity [4,5]. Besides, only a small amount of power is required to operate [6,7]. However, the structure nonlinearity and nonlinear electrostatic force seriously affect the performance of conventional micro-mass sensor [8][9][10].…”