Search results for "Mechanical system"

Devices based on semiconductor nanowires

2009

Recently, nanoelectromechanical systems (NEMS) have attracted much attention due to their unique properties and possible applications that differ greatly from those of microelectromechanical systems. NEMS operating frequencies may achieve giga- and terahertz levels and their power consumption and heat capacity is extremely low. Moreover, integration levels may reach 1012 devices per cm−2. In this review, we present techniques for integrating semiconductor materials in NEMS. In particular, we examine fabrication, structure, properties and potential applications of two main classes of NEMS, namely, resonators and switches.

Nanomanufacturing/Nanotechnology

2017

This chapter provides comprehensive knowledge regarding the fabrication of nanoproducts and element of micro-electromechanical systems using various techniques and processes. Both well-established techniques, such as nanomachining (ultra-precision) and new trends in improving nanoprocesses taking into account AFM, laser beam machining, electron beam machining processes are overviewed. The background of nanomachining processes, including typical machining operations such as turning, milling and grinding and different construction materials (metallic and nonmetallic), is outlined. The physical mechanisms responsible for the transition from brittle to ductile regime machining are explained. Mo…

MEMS-Based System for Structural Health Monitoring and Earthquake Observation in Sicily

2021

The implementation of systems for Structural Health Monitoring and Earthquake Observation is increasing in the last years owing to the development of new technologies which enable low-cost and small-size devices to be installed in large-scale or high-density applications. This paper introduces the implementation of monitoring systems, either for structural health assessment and earthquake observation. The applications are based in Sicily (Italy), a region characterized by a high seismic hazard and where the buildings are often old and vulnerable. The system relies on a MEMS (Micro Electro-Mechanical Systems) sensor, a 3-axial accelerometer which has been specifically selected in order to en…

Nanophotonics and Optical MEMS: Building All-Optical Satellites

2006

Evidence of Magnetoresistance in the Prussian Blue Lattice during a Voltammetric Scan

2008

This manuscript reports evidence of magnetoresistance effects in the Prussian Blue lattice during a voltammetric scan at room temperature. Accordingly, the PB is a well-known semiconductor that becomes surprisingly an almost metallic conductor in the presence of an internal magnetic field induced during the voltammetric scan. This offers appealing perspectives for the control of this interesting phenomenon from electrochemical techniques that could be used for the fabrication of the recent phase-change computational memories, which are electronically configurable. Herein, the PB magnetic properties have been monitored in situ by means of resonating magnetic microsensors based on the shift i…

Urban MEMS based seismic network for post-earthquakes rapid disaster assessment

2014

Abstract. In this paper, we introduce a project for the realization of the first European real-time urban seismic network based on Micro Electro-Mechanical Systems (MEMS) technology. MEMS accelerometers are a highly enabling technology, and nowadays, the sensitivity and the dynamic range of these sensors are such as to allow the recording of earthquakes of moderate magnitude even at a distance of several tens of kilometers. Moreover, thanks to their low cost and smaller size, MEMS accelerometers can be easily installed in urban areas in order to achieve an urban seismic network constituted by high density of observation points. The network is being implemented in the Acireale Municipality (…

Response determination of linear dynamical systems with singular matrices: A polynomial matrix theory approach

2017

Abstract An approach is developed based on polynomial matrix theory for formulating the equations of motion and for determining the response of multi-degree-of-freedom (MDOF) linear dynamical systems with singular matrices and subject to linear constraints. This system modeling may appear for reasons such as utilizing redundant DOFs, and can be advantageous from a computational cost perspective, especially for complex (multi-body) systems. The herein developed approach can be construed as an alternative to the recently proposed methodology by Udwadia and coworkers, and has the significant advantage that it circumvents the use of pseudoinverses in determining the system response. In fact, ba…

Electrical Conduction in Carbon Nanotubes under Mechanical Deformations

2009

The enormous potential of carbon nanotubes (CNTs) as primary components in electronic devices and NEMS necessitates the understanding and predicting of the effects of mechanical deformation on electron transport in CNTs. In principle, detailed atomic/electronic calculations can provide both the deformed configuration and the resulting electrical transport behavior of the CNT. However, the computational expense of these simulations limits the size of the CNTs that can be studied with this technique and a direct analysis of CNTs of the dimension used in nano-electronic devices, particularly multi-wall CNTs (MWNTs), seems prohibitive at the present. Here a computationally effective mixed finit…

Dielectrophoretic alignment and electrical characterization of CuO nanowire-based systems

2021

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…

Nanowires for NEMS Switches

2020

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…