Nanomechanical mass measurements through feature-based time series clustering

Adam P Neumann; Alfredo Gomez; Alexander R Nunn; John E Sader; Michael L Roukes

doi:10.1063/5.0176303

Nanomechanical mass measurements through feature-based time series clustering

Rev Sci Instrum. 2024 Feb 1;95(2):025001. doi: 10.1063/5.0176303.

Authors

Adam P Neumann¹, Alfredo Gomez¹, Alexander R Nunn¹, John E Sader², Michael L Roukes¹

Affiliations

¹ Department of Physics, California Institute of Technology, Pasadena, California 91125, USA.
² Graduate Aerospace Laboratories and Department of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA.

PMID: 38341716
DOI: 10.1063/5.0176303

Abstract

Recent years have seen explosive growth in miniaturized sensors that can continuously monitor a wide variety of processes, with applications in healthcare, manufacturing, and environmental sensing. The time series generated by these sensors often involves abrupt jumps in the detected signal. One such application uses nanoelectromechanical systems (NEMS) for mass spectrometry, where analyte adsorption produces a quick but finite-time jump in the resonance frequencies of the sensor eigenmodes. This finite-time response can lead to ambiguity in the detection of adsorption events, particularly in high event-rate mass adsorption. Here, we develop a computational algorithm that robustly eliminates this often-encountered ambiguity. A moving-window statistical test together with a feature-based clustering algorithm is proposed to automate the identification of single-event jumps. We validate the method using numerical simulations and demonstrate its application in practice using time-series data that are experimentally generated by molecules adsorbing onto NEMS sensors at a high event rate. This computational algorithm enables new applications, including high-throughput, single-molecule proteomics.