Dynamical Modeling and Simulation of a Laser-micromachined Vibration-based Micro Power Generator (original) (raw)
Related papers
A Laser-micromachined Vibrational to Electrical Power Transducer for Wireless Sensing Systems
Transducers ’01 Eurosensors XV, 2001
This paper presents the development of a vibration-induced power generator with total volume of ~1cm 3 which uses laser-micromachined springs to convert mechanical energy into useful electrical power by Faraday's Law of Induction. The goal of this project is to create a minimally sized electric power generator capable of producing enough voltage to drive low-power ICs and/or micro sensors for applications where ambient mechanical vibrations are present. Thus far, we have fabricated generators with total volume of 1cm 3 that are capable of producing up to 4.4V peak-to-peak, which have a maximum rms power of ~680ìW with loading resistance of 1500Ù. The mechanical vibration required to generate this electrical energy has frequencies ranging from 60 to 110Hz with ~200µm amplitude. We have demonstrated that this generator can drive an IR transmitter to send 140ms pulse trains every minute, or a 914.8MHz FM wireless temperature sensing system.
MEMS electrostatic micro-power generator for low frequency operation
This paper describes the analysis, simulation and testing of a microengineered motion-driven power generator, suitable for application in sensors within or worn on the human body. Micro-generators capable of powering sensors have previously been reported, but these have required high frequency mechanical vibrations to excite a resonant structure. However, body-driven movements are slow and irregular, with large displacements, and hence do not effectively couple energy into such generators. The device presented here uses an alternative, non-resonant operating mode. Analysis of this generator shows its potential for the application considered, and shows the possibility to optimise the design for particular conditions. An experimental prototype based on a variable parallel-plate capacitor operating in constant charge mode is described which confirms the analysis and simulation models. This prototype, when precharged to 30 V, develops an output voltage of 250 V, corresponding to 0.3 J per cycle. The experimental test procedure and the instrumentation are also described.
Design and performance of a microelectromagnetic vibration powered generator
2005
In this paper we report on the design, simulation and initial results of a microgenerator, which converts external vibrations into electrical energy. Power is generated by means of electromagnetic transduction with static magnets positioned either side of a moving coil located on a silicon structure designed to resonate laterally in the plane of the chip. In this paper the development and fabrication of a micromachined microgenerator that uses standard silicon based fabrication techniques and low cost, batch process is presented. Finite element simulations have been carried out using ANSYS to determine an optimum geometry for the microgenerator. Electromagnetic FEA simulations using Ansoft's Maxwell 2D software have shown voltage levels of 4 to 9V can be generated from the single beam generator designs. Initial results at atmospheric pressure yield 0.5µW at 9.81ms -2 and 9.5 kHz and emphasise the importance of reducing unwanted loss mechanisms such as air damping.
A micro electromagnetic generator for vibration energy harvesting
Vibration energy harvesting is receiving a considerable amount of interest as a means for powering wireless sensor nodes. This paper presents a small (component volume 0.1 cm 3 , practical volume 0.15 cm 3) electromagnetic generator utilizing discrete components and optimized for a low ambient vibration level based upon real application data. The generator uses four magnets arranged on an etched cantilever with a wound coil located within the moving magnetic field. Magnet size and coil properties were optimized, with the final device producing 46 µW in a resistive load of 4 k from just 0.59 m s −2 acceleration levels at its resonant frequency of 52 Hz. A voltage of 428 mVrms was obtained from the generator with a 2300 turn coil which has proved sufficient for subsequent rectification and voltage step-up circuitry. The generator delivers 30% of the power supplied from the environment to useful electrical power in the load. This generator compares very favourably with other demonstrated examples in the literature, both in terms of normalized power density and efficiency. (Some figures in this article are in colour only in the electronic version)
A scalable concept for micropower generation using flow-induced self-excited oscillations
2010
Inspired by music-playing harmonicas that create tones via oscillations of reeds when subjected to air blow, this paper entails a concept for microwind power generation using flow-induced self-excited oscillations of a piezoelectric beam embedded within a cavity. Specifically, when the volumetric flow rate of air past the beam exceeds a certain threshold, the energy pumped into the structure via nonlinear pressure forces offsets the system's intrinsic damping setting the beam into self-sustained limit-cycle oscillations. The vibratory energy is then converted into electricity through principles of piezoelectricity. Experimental and theoretical results are presented demonstrating the feasibility of the proposed concept.
2005
In this paper we report on the design, simulation and fabrication of a microgenerator, which converts external vibrations into electrical energy. Power is generated by means of electromagnetic transduction with static magnets positioned either side of a moving coil located on a silicon structure designed to resonate laterally in the plane of the chip. Previous millimetre scale electromagnetic generators have been fabricated using discrete components and traditional fabrication techniques. In this paper the development and fabrication of a micromachined microgenerator that uses standard silicon-based fabrication techniques and low-cost, batch process is presented. Finite element simulations have been carried out using ANSYS to determine an optimum geometry for the microgenerator. Electromagnetic FEA simulations using Ansoft's Maxwell 2D software have shown voltage levels of 4 to 9V can be generated from the single beam generator designs.
Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems, 2006
This paper presents a silicon microgenerator, fabricated using standard silicon micromachining techniques, which converts external ambient vibrations into electrical energy. Power is generated by an electromagnetic transduction mechanism with static magnets positioned on either side of a moving coil, which is located on a silicon structure designed to resonate laterally in the plane of the chip. The volume of this device is approximately 100 mm3. ANSYS finite element analysis (FEA) has been used to determine the optimum geometry for the microgenerator. Electromagnetic FEA simulations using Ansoft’s Maxwell 3D software have been performed to determine the voltage generated from a single beam generator design. The predicted voltage levels of 0.7–4.15 V can be generated for a two-pole arrangement by tuning the damping factor to achieve maximum displacement for a given input excitation. Experimental results from the microgenerator demonstrate a maximum power output of 104 nW for 0.4g (g=9.81 m s−1) input acceleration at 1.615 kHz. Other frequencies can be achieved by employing different geometries or materials.
Design and fabrication of a micro electromagnetic vibration energy harvester
This paper presents a new micro electromagnetic energy harvester that can convert transverse vibration energy to electrical power. It mainly consists of folded beams, a permanent magnet and copper planar coils. The calculated value of the natural frequency is 274 Hz and electromagnetic simulation shows that the magnetic flux density will decrease sharply with increasing space between the magnet and coils. A prototype has been fabricated using MEMS micromachining technology. The testing results show that at the resonant frequency of 242 Hz, the prototype can generate 0.55 W of maximal output power with peak-peak voltage of 28 mV for 0.5g (g D 9.8 m/s 2 / external acceleration.
Modeling and Simulation of a Piezoelectric Micro-Power Generator
Piezoelectric Micro-Power Generators (PMPGs) convert the deformations produced by kinetic energy harvested from mechanical vibrations to an electrical charge via the direct piezoelectric effect. The current surge in micro-scale and lowpower devices allows PMPGs to provide a convenient alternative power source to traditional sources in various applications. In this work we compare the PMPG modeling and simulation results obtained using four different approaches; (i) COMSOL Multiphysics 3.5a, (ii) Coventor, (iii) ANSYS and (iv) Lumped element analysis. Firstly, static deflection of the mass and the maximum stress in the support beams are obtained as functions of the voltage. Then, the eigenvalue problem of the MPG is solved to obtain the lowest four natural frequencies and mode shapes of the MPG. Finally the transient response of the PMPG is determined along with its power generation capacity. It is found that the four approaches closely agree with each other. The simulations provide the basis for optimal design and fabrication of the PMPG.
MEMS vibrational energy harvesters
Science and Technology of Advanced Materials
In this paper, we look into the fundamental mechanism to retrieve the power from physical vibrations by using microelectromechanical systems (MEMS) energy harvesters. An analytical model is presented for the velocity-damped resonant generator (VDRG) that delivers electrical power through the power enhancement mechanism using the mechanical resonance of a suspended mass. Deliverable power is also analytically discussed with respect to the theoretical limit, and a view to understand the VDRG behaviors is presented in association with the impedance matching condition and the quality factors. Mechano-electric power conversions including electrostatic induction, electromagnetic induction, and piezoelectric effect are discussed to study the scaling effect. Recent examples of MEMS VDRGs are reviewed and evaluated in terms of the power density.