Title: Hexagonal boron nitride nanomechanical resonators with spatially visualized motion

Abstract

Atomic layers of hexagonal boron nitride (h-BN) crystal are excellent candidates for structural materials as enabling ultrathin, two-dimensional (2D) nanoelectromechanical systems (NEMS) due to the outstanding mechanical properties and very wide bandgap (5.9 eV) of h-BN. In this work, we report the experimental demonstration of h-BN 2D nanomechanical resonators vibrating at high and very high frequencies (from ~ 5 to ~ 70 MHz), and investigations of the elastic properties of h-BN by measuring the multimode resonant behavior of these devices. First, we demonstrate a dry-transferred doubly clamped h-BN membrane with ~ 6.7 nm thickness, the thinnest h-BN resonator known to date. In addition, we fabricate circular drumhead h-BN resonators with thicknesses ranging from ~ 9 to 292 nm, from which we measure up to eight resonance modes in the range of ~ 18 to 35 MHz. Combining measurements and modeling of the rich multimode resonances, we resolve h-BN’s elastic behavior, including the transition from membrane to disk regime, with built-in tension ranging from 0.02 to 2 N m^-1. The Young’s modulus of h-BN is determined to be EY≈392 GPa from the measured resonances. The ultrasensitive measurements further reveal subtle structural characteristics and mechanical properties of the suspended h-BN diaphragms, includingmore » anisotropic built-in tension and bulging, thus suggesting guidelines on how these effects can be exploited for engineering multimode resonant functions in 2D NEMS transducers.« less

Authors:

Zheng, Xu-Qian ^[1]; Lee, Jaesung ^[1]; Feng, Philip X. -L. ^[1]

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+ Show Author Affiliations

1. Case Western Reserve Univ., Cleveland, OH (United States)

Publication Date:

Mon Jul 31 00:00:00 EDT 2017

Research Org.:

Case Western Reserve Univ., Cleveland, OH (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE)

OSTI Identifier:

1425389

Grant/Contract Number:  

EE0006719

Resource Type:

Journal Article: Accepted Manuscript

Journal Name:

Microsystems & Nanoengineering (Online)

Additional Journal Information:

Journal Volume: 3; Journal ID: ISSN 2055-7434

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; 42 ENGINEERING; Hexagonal boron nitride (h-BN); multimode resonances; nanoelectromechanical systems (NEMS); resonators; spatial mapping; Young’s modulus