Electrostatic actuated mems for precision AC voltage references
The purpose of this paper is to present results on the design of electrostatic actuated micro- electromechanical systems (MEMS) aiming at developing AC voltage references through mechanical-electrical transduction for electrical metrology and more generally for miniaturized instrumentation. Several test MEMS architectures (targeted AC voltages from 10 V up to 100 V) for the vertical motion have been designed and are under fabrication by an epitaxial silicon on insulator (SOI) surface micromachining process with the aim to investigate the potentialities of the different structures with respect to the geometrical dispersion, the strain sensitivity and the electrical stability.
Advantages of alternative actuating signal for MEMS actuators
In this paper, we report the different advantages of using AC actuating signal for driving MEMS actuators. The study is based upon micro-mirror devices used in scanning or digital mode. In scanning mode, an AC signal can be used to overcome difficulties induced by the high voltages required in electrostatic systems by taking advantage of the double rectifying effect of electrostatic actuation within a second order system. On the other hand, when the pull-in effect is used, charge injection occurs after a long time in the deflected position except when the landing electrodes are electro-statically separated from the control electrodes. An AC signal also eliminates charge injection particularly if a bipolar signal is used. Long term experiments have demonstrated the reliability of such a signal command to avoid injection of electric charges.
La participacion de los stakeholders en las iniciativas de branding del hospital en las redes sociales: una propuesta de modelo para construir marcas colectivas
Introduction : All health organizations face many managerial and economic challenges such as the consolidation of private and international hospitals, the increasingly interest of society for health education issues or the development of telemedicine. In this framework, many organizations prioritize social media as the main corporate communication tool for building a reputed brand in a collective way along with stakeholders. Objectives : This paper aims to identify a communication model allowing hospitals to efficiently apply branding initiatives on social media in order to build a brand in a collective way with stakeholders. Methodology : We carried out a literature review about corporate communication, health communication, branding and social media; and, then, we proposed the PET Model for Branding Hospitals on Social Media. Results and Conclusion : We conclude that hospitals should create a multidisciplinar corporate communication department, implement management initiatives for allowing health professionals have more time for using social media and integrate health education and patient’s empowerment in every communication initiative.