We report on theoretical and experimental investigation of parametric amplification of acoustically excited vibrations in micromachined single-crystal silicon cantilevers electrostatically actuated by fringing fields. The device dynamics are analyzed using the Mathieu-Duffing equation, obtained using the Galerkin order reduction technique. Our experimental results show that omnidirectional acoustic pressure used as a noncontact source for linear harmonic driving is a convenient and versatile tool for the mechanical dynamic characterization of unpackaged, nonintegrated microstructures. The fringing field's electrostatic actuation allows for efficient parametric amplification of an acoustic signal. The suggested amplification approach may have applications in a wide variety of micromechanical devices, including resonant sensors, microphones and microphone arrays, and hearing aids. It can be used also for upward frequency tuning.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10891934 | PMC |
http://dx.doi.org/10.3390/mi15020257 | DOI Listing |
Nat Commun
January 2025
CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, CAS Center for Excellence in Complex System Mechanics, University of Science and Technology of China, Hefei, Anhui, China.
Control of crack propagation is crucial to make tougher heterogeneous materials. As a crack interacts with material heterogeneities, its front distorts and adopts complex tortuous configurations. While the behavior of smooth cracks with straight fronts in homogeneous materials is well understood, the toughening by rough cracks with tortuous fronts in heterogeneous materials remains unsolved.
View Article and Find Full Text PDFJ Acoust Soc Am
December 2024
Department of Mechanical Engineering, Rowan University, Glassboro, New Jersey 08028, USA.
Space-time modulation opens the door for unprecedented wave behavior control, such as nonreciprocal wave manipulation. Here is proposed a one-dimensional space-time modulated membrane system aiming to realize a kind of acoustic metamaterial with space-time modulated effective density. Three different approaches, namely, the effective medium method, transfer matrix method, and time-domain simulation, are applied to analyze the acoustic response of the system under a monochromatic incidence.
View Article and Find Full Text PDFJ Oral Pathol Med
November 2024
Human and Medical Genetics Laboratory, Federal University of Jataí, Jataí, Goiás, Brazil.
Background: Lip exposure to carcinogens lead to several disorders, such as actinic cheilitis (AC) and lower lip squamous cell carcinoma (LLSCC). Although several studies have described important pathways in lip carcinogenesis, the comprehension of association of target genes in this process and their association with tumor microenvironment still need to be better understood.
Methods: Tissue samples of 30 AC and 17 LLSCC cases were included for histopathological analysis, immunohistochemical expression of CD4, CD8, and PD-L1, and fluorescence in situ hybridization for AURKA, AURKB, TP53, PTEN, CCND1, and MYC.
In this study, we present the experimental proof of concept of the polarization-based filled-aperture coherent combination of two distinct broadband (sub-20 fs transform limited pulse duration at around 795 nm central wavelength) optical parametric chirped pulse amplification systems in free space. An average combination efficiency of 90% is demonstrated.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!