Dynamic range enhancement of nonlinear nanomechanical resonant cantilevers for highly sensitive NEMS gas/mass sensor applications

• Published in: Journal of micromechanics and microengineering Vol. 20; no. 4; p. 045023
• Main Authors: Kacem, N, Arcamone, J, Perez-Murano, F, Hentz, S
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.04.2010; Institute of Physics
• Subjects: Amplitudes; Applied sciences; Cantilever beams; Electronics; Engineering Sciences; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mathematical analysis; Mathematical models; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Nanocomposites; Nanomaterials; Nanostructure; Nonlinearity; Physics; Precision engineering, watch making; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Density measurement; Lithography; Capacitive transducer; Measurement sensor; Nanoelectromechanical device; Large displacement; Bernoulli Euler model; Experimental study; Cantilever beam; Vibrations; Electrical measurement; Complementary MOS technology; Monolithic integrated circuits; Modelling; Silicon; Non linear effect; Gas sensors; Resonators; Gas detector; Multidisciplinary; Nanotechnology
• ISSN: 0960-1317; 1361-6439
• DOI: 10.1088/0960-1317/20/4/045023

This paper describes a comprehensive nonlinear multiphysics model based on the Euler--Bernoulli equation that remains valid up to large displacements in the case of electrostatically actuated nanocantilevers. This purely analytical model takes into account the fringing field effects which are significant for thin resonators. Analytical simulations show very good agreement with experimental electrical measurements of silicon nanodevices using wafer-scale nanostencil lithography (nSL), monolithically integrated with CMOS circuits. Close-form expressions of the critical amplitude are provided in order to compare the dynamic ranges of NEMS cantilevers and doubly clamped beams. This model allows designers to cancel out nonlinearities by tuning some design parameters and thus gives the possibility of driving the cantilever beyond its critical amplitude. Consequently, the sensor performance can be enhanced by being optimally driven at very large amplitude, while maintaining linear behavior.