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Lecture

Introduction to LEM and Equivalent Circuits

In course

MICRO-470: Scaling laws in micro & nanosystems

This class adresses scaling laws in MEMS/NEMS. The dominant physical effects and scaling effects when downsizing sensors and actuators in microsystems are discussed, across a broad range of actuation principles. ...

Description

This lecture introduces the concept of Lumped Element Model (LEM) as a way to simplify systems into discrete elements with energy exchange. It covers the process of 'lumping' a system, provides examples in mechanical and thermal systems, and explains the use of equivalent circuits for LEM. The slides also discuss the conversion between electrical, mechanical, fluidic, and thermal domains in equivalent circuits.

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Instructors (3)

Philippe Renaud

Philippe Renaud is Professor at the Microsystem Laboratory (LMIS4) at EPFL. He is also the scientific director of the EPFL Center of MicroNanoTechnology (CMI). His main research area is related to micronano technologies in biomedical applications (BioMEMS) with emphasis on cell-chips, nanofluidics and bioelectronics. Ph. Renaud is invloved in many scientifics papers in his research area. He received his diploma in physics from the University of Neuchâtel (1983) and his Ph.D. degree from the University of Lausanne (1988). He was postdoctoral fellow at University of California, Berkeley (1988-89) and then at the IBM Zürich Research Laboratory in Switzerland (1990-91). In 1992, he joined the Sensors and Actuators group of the Swiss Center for Electronics and Microtechnology (CSEM) at Neuchâtel, Switzerland. He was appointed assistant professor at EPFL in 1994 and full professor in 1997. In summer 1996, he was visiting professor at the Tohoku University, Japan. Ph. Renaud is active in several scientific committee (scientific journals, international conferences, scientific advisory boards of companies, PhD thesis committee). He is also co-founder of the Nanotech-Montreux conference. Ph. Renaud is committed to valorization of basic research through his involvement in several high-tech start-up companies.

Niels Quack

Prof. Dr. Niels Quack received the M.Sc. degree from Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, in 2005, and the Dr.Sc. degree from Eidgenössische Technische Hochschule Zürich (ETH), Zürich, Switzerland, in 2010. From 2011 to 2015, he was Postdoctoral Researcher and Visiting Scholar with the Integrated Photonics Laboratory, Berkeley Sensor and Actuator Center, University of California, Berkeley, CA, USA. From 2014 to 2015, he was Senior MEMS Engineer with Sercalo Microtechnology, Neuchâtel, Switzerland. He is currently an SNSF Assistant Professor with Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland. He has authored and co-authored more than 50 papers in leading technical journals and conferences. His research interests include photonic micro and nanosystems, with an emphasis on diamond photonics and silicon photonic MEMS. He is Steering Committee Member of the IEEE International Conference on Optical MEMS and Nanophotonics (OMN) and served as General Chair of the IEEE OMN 2018 and the Latsis Symposium 2019 on Diamond Photonics. He is a Senior Member of IEEE, Member of The Optical Society (OSA) and life member of SPIE.

Official source

Ontological neighbourhood

Physics

Electromagnetism: Electrical networks

Related concepts (15)

Lumped-element model

The lumped-element model (also called lumped-parameter model, or lumped-component model) is a simplified representation of a physical system or circuit that assumes all components are concentrated at a single point and their behavior can be described by idealized mathematical models. The lumped-element model simplifies the system or circuit behavior description into a topology. It is useful in electrical systems (including electronics), mechanical multibody systems, heat transfer, acoustics, etc.

Equivalent circuit

In electrical engineering, an equivalent circuit refers to a theoretical circuit that retains all of the electrical characteristics of a given circuit. Often, an equivalent circuit is sought that simplifies calculation, and more broadly, that is a simplest form of a more complex circuit in order to aid analysis. In its most common form, an equivalent circuit is made up of linear, passive elements. However, more complex equivalent circuits are used that approximate the nonlinear behavior of the original circuit as well.

Distributed-element model

In electrical engineering, the distributed-element model or transmission-line model of electrical circuits assumes that the attributes of the circuit (resistance, capacitance, and inductance) are distributed continuously throughout the material of the circuit. This is in contrast to the more common lumped-element model, which assumes that these values are lumped into electrical components that are joined by perfectly conducting wires.

Network analysis (electrical circuits)

In electrical engineering and electronics, a network is a collection of interconnected components. Network analysis is the process of finding the voltages across, and the currents through, all network components. There are many techniques for calculating these values; however, for the most part, the techniques assume linear components. Except where stated, the methods described in this article are applicable only to linear network analysis.

Thévenin's theorem

As originally stated in terms of direct-current resistive circuits only, Thévenin's theorem states that "Any linear electrical network containing only voltage sources, current sources and resistances can be replaced at terminals A–B by an equivalent combination of a voltage source Vth in a series connection with a resistance Rth." The equivalent voltage Vth is the voltage obtained at terminals A–B of the network with terminals A–B open circuited.

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