Graphene as a Massless Electrode for Ultrahigh-Frequency Piezoelectric Nanoelectromechanical Systems

Abstract

Designing "ideal electrodes" that simultaneously guarantee low mechanical damping and electrical loss as well as high electromechanical coupling in ultralow-volume piezoelectric nanomechanical structures can be considered to be a key challenge in the NEMS field. We show that mechanically transferred graphene, floating at van der Waals proximity, closely mimics "ideal electrodes" for ultrahigh frequency (0.2 GHz < f0 < 2.6 GHz) piezoelectric nanoelectromechanical resonators with negligible mechanical mass and interfacial strain and perfect radio frequency electric field confinement. These unique attributes enable graphene-electrode-based piezoelectric nanoelectromechanical resonators to operate at their theoretically "unloaded" frequency-limits with significantly improved electromechanical performance compared to metal-electrode counterparts, despite their reduced volumes. This represents a spectacular trend inversion in the scaling of piezoelectric electromechanical resonators, opening up new possibilities for the implementation of nanoelectromechanical systems with unprecedented performance.

Acoustically actuated ultra-compact NEMS magnetoelectric antennas

“…The resonant bodies of the NEMS ME resonators were a 500 nm AlN thin film supporting a [Fe 7 Ga 2 B 1 (45 nm)/Al 2 O 3 (5 nm)] × 10 (hereafter termed FeGaB) thin-film ME heterostructures fully suspended on a Si substrate, where AlN and FeGaB (see Supplementary Note 1 for magnetic properties characterization) serve as the piezoelectric and magnetostrictive element of the ME heterostructure, respectively. The use of a NEMS resonator with an ultra-thin (thickness, T = 500 nm) AlN thin film enables efficient on-chip acoustic transduction with ultra-low energy dissipation 25 , 26 . In this work, the demonstrated ME antennas span a wide range of frequencies from 60 MHz to 2.5 GHz, which are realized by a geometric design of resonating plates that exhibit different mode of vibrations (Supplementary Note 6 ).…”

Manufacture and characterization of graphene membranes with suspended silicon proof masses for MEMS and NEMS applications

“…The atomically thin structure of graphene (atom-layer distance of ~0.335 nm) and its remarkable mechanical 1 and electrical properties 2 (Young's modulus of up to ~1 TPa and charge carrier mobility of up to 200,000 cm 2 V −1 s −1 ) make it a very promising membrane and transducer material for micro-and nanoelectromechanical system (MEMS & NEMS) applications [3][4][5][6][7][8][9] .…”

Topochemical transformation of two-dimensional single crystalline Na0.5Bi0.5TiO3–BaTiO3 platelets from Na0.5Bi4.5Ti4O15 precursors and their piezoelectricity

“…Energy harvesting (EH) [1][2][3] and nanoelectromechanical (NEM) systems [4][5][6][7] have attracted great interest in the scientific and engineering communities, due to their potential application in smart and portable electronic devices. Flexible and stretchable nanogenerators, which are capable of exhibiting strain induced piezoelectric polarization, are typically the core part of EH systems for scavenging small amounts of energy effectively, through mechanical action such as rolling, bending, or even applied pressure through human motion.…”