Search results for "MEMS"
showing 10 items of 20 documents
Mechanical Bistable Structures for Microrobotics and Mesorobotics from Microfabrication to Additive Manufacturing
2018
International audience; The use of mechanical bistable structures in the design of microrobots and mesorobots has many advantages especially for flexible robotic structures. However, depending on the fabrication technology used, the adequacy of theoretical and experimental mechanical behaviors can vary widely. In this paper, we present the manufacturing results of bistable structures made with two extensively used contemporary technologies: MEMS and FDM additive manufacturing. Key issues of these fabrication technologies are discussed in the context of microrobotics and mesorobotics applications.
Reverberation reduction in capacitive micromachined ultrasonic transducers (CMUTs) by front-face reflectivity minimization
2015
Abstract Front-face acoustic reflectivity of ultrasonic imaging transducers, due to acoustic impedance mismatch with the propagation medium, may cause reverberation phenomena during wideband pulse-echo operation. Front-face reflectivity may be reduced by promoting the transmission of the echoes, received from the medium, to the transducer backing, and by maximizing the mechanical-to-electrical energy conversion and dissipation by tuning the electrical load impedance connected to the transducer. In Capacitive Micromachined Ultrasonic Transducers (CMUTs), the energy transfer from the medium to the backing is very low due to the large impedance mismatch between the medium and the transducer su…
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 (…
La rete museale intradiocesana di Erice
2014
L'esperienza di valorizzazione e musealizzazione dei beni mobili e immobili di pertinenza ecclesiastica di Erice maturata all'interno del progetto culturale diocesano "La Montagna del Signore". Nel contributo vengono illustrati i percorsi di fruizione e i metodi gestionali consolidati da oltre un decennio.
Analytical Solutions of Viscoelastic Nonlocal Timoshenko Beams
2022
A consistent nonlocal viscoelastic beam model is proposed in this paper. Specifically, a Timoshenko bending problem, where size- and time-dependent effects cannot be neglected, is investigated. In order to inspect scale phenomena, a stress-driven nonlocal formulation is used, whereas to simulate time-dependent effects, fractional linear viscoelasticity is considered. These two approaches are adopted to develop a new Timoshenko bending model. Analytical solutions and application samples of the proposed formulation are presented. Moreover, in order to show influences of viscoelastic and size effects on mechanical response, parametric analyses are provided. The contributed results can be usefu…
Optimization of Low-Cost Monitoring Systems for On-Site Earthquake Early-Warning of Critical Infrastructures
2020
In the last years, monitoring systems based on low-cost and miniaturized sensors (MEMS) revealed as a very successful compromise between the availability of data and their quality. Also applications in the field of seismic and structural monitoring have been constantly increasing in term of number and variety of functions. Among these applications, the implementation of systems for earthquake early warning is a cutting-edge topic, mainly for its relevance for the society as millions of peoples in various regions of the world are exposed to high seismic hazard. This paper introduces the optimization of an already established seismic (and structural) monitoring system, that would make it suit…
Reti sismiche urbane per monitoraggio sismico monitoraggio strutturale ed allerta precoce
2021
In questa tesi, viene effettuato un analisi preliminare in cui si mette in evidenza come l'italia sia un paese a rischio sismico, poichè possiede molti centri storici con strutture non progettate per eventi sismici di media entità. Si è prestato molta attenzione su quante vite umane vengono salvate dopo un terremoto catastrofico. L'analisi fa emergere come, è importante essere tempestivi nell'estrarre le persone rimaste sotto le macerie, poichè la percentuale di persone estratte vive si mantiene alta solo entro le 48 ore dall'evento. Dopo 96 ore questa percentule si attesta a 0. In eventi passati spesso i soccorsi sono arrivati con giorni di ritardo nelle zone più devastate. L'obbiettivo ch…
Mikrojärjestelmien virtausdynamiikka numeerisen mallintamisen näkökulmasta
2005
Aligned microcontact printing of biomolecules on microelectronic device surfaces
2001
Microcontact printing (/spl mu/CP) of extracellular matrix proteins is a fascinating approach to control cell positioning and outgrowth, which is essential in the development of applications ranging from cellular biosensors to tissue engineering. Microelectronic devices can be used to detect the activity from a large number of recording sites over the long term. However, signals from cells can only be recorded at small sensitive spots. Here, the authors present an innovative setup to perform aligned /spl mu/CP of extracellular matrix proteins on microelectronic devices in order to guide the growth of electrogenic cells specifically to these sensitive spots. The authors' system is based on t…
A novel device for assessing the health risk caused by hand-arm vibrations in olives harvesting
2012
The mechanization of olive harvesting is very important both to reduce the costs of production and to assure the oil quality because the manual harvest does not allow to operate at the right time and also need a long period to be completed. The use of portable shakers, that are spreading more than others typologies, can give a solution to the problem. However, the use of such equipment may involve risk of exposure to hand-transmitted vibration. The aim of this study was to assess the level of exposure to hand-arm vibration of the operators using portable shakers (reference standards UNI EN ISO 5349-1:2004, Italian Low Decree 81/2008). The research presented here concerns the definition of a…