0000000000341566
AUTHOR
Liga Jasulaneca
Dielectrophoretic alignment and electrical characterization of CuO nanowire-based systems
Abstract Dielectrophoresis is used to assemble nanowires between metallic electrodes to form scalable functional interconnects. The dielectrophoresis parameters are investigated for semiconductor copper oxide (CuO) nanowires that are desirable for energy conversion and storage, gas sensors and nanoelectromechanical systems. Experimental yields of multiple- and single-nanowire interconnects are explored at dielectrophoresis frequencies from 500 Hz to 500 kHz. The electrical properties of nanowire-electrode physical contact interfaces formed by dielectrophoresis, metal deposition, and dry mechanical transfer are investigated. The electrical transport mechanism in these interconnects is determ…
Fabrication and Characterization of Double- and Single-Clamped CuO Nanowire Based Nanoelectromechanical Switches
Electrostatically actuated nanoelectromechanical (NEM) switches hold promise for operation with sharply defined ON/OFF states, high ON/OFF current ratio, low OFF state power consumption, and a compact design. The present challenge for the development of nanoelectromechanical system (NEMS) technology is fabrication of single nanowire based NEM switches. In this work, we demonstrate the first application of CuO nanowires as NEM switch active elements. We develop bottom-up and top-down approaches for NEM switch fabrication, such as CuO nanowire synthesis, lithography, etching, dielectrophoretic alignment of nanowires on electrodes, and nanomanipulations for building devices that are suitable f…
Cryogenic nanoelectromechanical switch enabled by Bi2Se3 nanoribbons
Abstract Nanoelectromechanical (NEM) switches are potential candidates for memory and logic devices for low standby-current and harsh environment applications. Cryogenic operation of these devices would allow to use them, e.g., in space probes and in conjunction with quantum computers. Herein, it is demonstrated that cryogenic application requirements such as good flexibility and conductivity are satisfied by using Bi2Se3 nanoribbons as active elements in NEM switches. Experimental proof of principle NEM switching at temperatures as low as 5 K is achieved in volatile and non-volatile reversible regimes, exhibiting distinct ON and OFF states, backed by theoretical modelling. The results open…
Young’s modulus and indirect morphological analysis of Bi2Se3nanoribbons by resonance measurements
An electrostatically induced resonance behaviour of individual topological insulator Bi2Se3 nanoribbons grown by a catalyst free vapour-solid synthesis was studied in situ by scanning electron microscopy. It was demonstrated that the relation between the resonant frequencies of vibrations in orthogonal planes can be applied to distinguish the nanoribbons with rectangular cross-sections from the nanoribbons having step-like morphology (terraces). The average Young's modulus of the Bi2Se3 nanoribbons with rectangular cross-sections was found to be 44 ± 4 GPa.
Determination of Young’s modulus of Sb2S3 nanowires by in situ resonance and bending methods
In this study we address the mechanical properties of Sb2S3 nanowires and determine their Young’s modulus using in situ electric-field-induced mechanical resonance and static bending tests on individual Sb2S3 nanowires with cross-sectional areas ranging from 1.1·104 nm2 to 7.8·104 nm2. Mutually orthogonal resonances are observed and their origin explained by asymmetric cross section of nanowires. The results obtained from the two methods are consistent and show that nanowires exhibit Young’s moduli comparable to the value for macroscopic material. An increasing trend of measured values of Young’s modulus is observed for smaller thickness samples.
Extra tension at electrode-nanowire adhesive contacts in nano-electromechanical devices
Abstract We report a strong tangential component of the reaction force at electrode to nanowire adhesive contact which was previously established using electrostatic attraction. The reaction force tangential component absolute value was found to be comparable to or even bigger than the corresponding normal component. This effect is important for understanding of the mechanics of nano-electromechanical devices. Both the experiment and the corresponding theory are presented. Fitting of the obtained analytical solutions to experimental data was used to measure the reaction force acting at the contact for several nanowire-electrode configurations.
High-Yield Growth and Tunable Morphology of Bi2Se3 Nanoribbons Synthesized on Thermally Dewetted Au
The yield and morphology (length, width, thickness) of stoichiometric Bi2Se3 nanoribbons grown by physical vapor deposition is studied as a function of the diameters and areal number density of the Au catalyst nanoparticles of mean diameters 8–150 nm formed by dewetting Au layers of thicknesses 1.5–16 nm. The highest yield of the Bi2Se3 nanoribbons is reached when synthesized on dewetted 3 nm thick Au layer (mean diameter of Au nanoparticles ~10 nm) and exceeds the nanoribbon yield obtained in catalyst-free synthesis by almost 50 times. The mean lengths and thicknesses of the Bi2Se3 nanoribbons are directly proportional to the mean diameters of Au catalyst nanoparticles. In contrast, the me…
Size Distribution, Mechanical and Electrical Properties of CuO Nanowires Grown by Modified Thermal Oxidation Methods
Size distribution, Young&rsquo
Review: Electrostatically actuated nanobeam-based nanoelectromechanical switches – materials solutions and operational conditions
This review summarizes relevant research in the field of electrostatically actuated nanobeam-based nanoelectromechanical (NEM) switches. The main switch architectures and structural elements are briefly described and compared. Investigation methods that allow for exploring coupled electromechanical interactions as well as studies of mechanically or electrically induced effects are covered. An examination of the complex nanocontact behaviour during various stages of the switching cycle is provided. The choice of the switching element and the electrode is addressed from the materials perspective, detailing the benefits and drawbacks for each. An overview of experimentally demonstrated NEM swi…
Nanowires for NEMS Switches
Nanoelectromechanical systems (NEMS) are a promising novel technology for operation in extreme conditions (e.g. high temperature and radiation levels), where complementary semiconductor technology devices might fail due to electronic instability. An example for a NEMS device is a nanowire-based switch, which employs mechanical deflection of a nanowire to open and close an electrical circuit. To date, assembly and operation of individual nanowire based NEMS switches have been successfully demonstrated at laboratory level, but their further technological development remains a challenge. This chapter gives an insight into the current advances in applications of nanowires for NEMS switches. Syn…
Resonance assisted jump-in voltage reduction for electrostatically actuated nanobeam-based gateless NEM switches.
Electrostatically actuated nanobeam-based electromechanical switches have shown promise for versatile novel applications, such as low power devices. However, their widespread use is restricted due to poor reliability resulting from high jump-in voltages. This article reports a new method for lowering the jump-in voltage by inducing mechanical oscillations in the active element during the switching ON process, reducing the jump-in voltage by more than three times. Ge0.91Sn0.09 alloy and Bi2Se3 nanowire-based nanoelectromechanical switches were constructed in situ to demonstrate the operation principles and advantages of the proposed method.
Electric current induced modification of germanium nanowire NEM switch contact.
We present an investigation of contact properties of a germanium (Ge) nanowire based nanoelectromechanical (NEM) switch in its ON state. The contact stiffness in the ON state was evaluated by detecting the nanowire's resonance frequency. It was found that the resonance frequency increases when electric current flows through the nanowire/counter electrode contact area. The reason for modification in the contact area is referred to as electric-current-induced processes in the native oxide layer covering the nanowires. The presented resonance shift method is a simple way to indicate strengthening of the nanowire/counter electrode contact area without disassembling the contact.