Design, simulation and fabrication of a novel contact-enhanced MEMS inertial switch with a movable contact point

Cai, Haogang; Ding, Guifu; Yang, Zhuoqing; Su, Zhongqing; Zhou, Jing; Hong, Wang

doi:10.1088/0960-1317/18/11/115033

Cited by 49 publications

(30 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compared to the accelerometer, the inertial microswitch is both a sensor and an actuator. Firstly, this purely mechanical trigger in the inertial switch is superior to the accelerometer because they can avoid the risk of mis-operation from electromagnetic interference [5]. Secondly, it is not necessary to measure the continuously varying acceleration signals in some long-lifetime or small scale systems because of the limited power supply, where accelerometers are not suitable because of the necessity for a continuous power supply [6].…”

Section: Introductionmentioning

confidence: 99%

“…Deng et al designed the inertial microswitch with double flexible electrodes based on the silicon bulk micromachining process, which can further improve the contact effect [16]. Several kinds of vertically-driven inertial microswitches with flexible contacts have been proposed and fabricated in our previous works [5,6,17,18,19]. In these cases, one elastic crossbeam was regarded as the stationary electrode instead of rigid electrode, which indicates that the contact duration has been extended to some extent.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Design and Optimization of a Stationary Electrode in a Vertically-Driven MEMS Inertial Switch for Extending Contact Duration

Yang

et al. 2017

Sensors

View full text Add to dashboard Cite

A novel micro-electro-mechanical systems (MEMS) inertial microswitch with a flexible contact-enhanced structure to extend the contact duration has been proposed in the present work. In order to investigate the stiffness k of the stationary electrodes, the stationary electrodes with different shapes, thickness h, width b, and length l were designed, analyzed, and simulated using ANSYS software. Both the analytical and the simulated results indicate that the stiffness k increases with thickness h and width b, while decreasing with an increase of length l, and it is related to the shape. The inertial micro-switches with different kinds of stationary electrodes were simulated using ANSYS software and fabricated using surface micromachining technology. The dynamic simulation indicates that the contact time will decrease with the increase of thickness h and width b, but increase with the length l, and it is related to the shape. As a result, the contact time decreases with the stiffness k of the stationary electrode. Furthermore, the simulated results reveal that the stiffness k changes more rapidly with h and l compared to b. However, overlarge dimension of the whole microswitch is contradicted with small footprint area expectation in the structure design. Therefore, it is unreasonable to extend the contact duration by increasing the length l excessively. Thus, the best and most convenient way to prolong the contact time is to reduce the thickness h of the stationary electrode while keeping the plane geometric structure of the inertial micro-switch unchanged. Finally, the fabricated micro-switches with different shapes of stationary electrodes have been evaluated by a standard dropping hammer system. The test maximum contact time under 288 g acceleration can reach 125 µs. It is shown that the test results are in accordance with the simulated results. The conclusions obtained in this work can provide guidance for the future design and fabrication of inertial microswitches.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Design and Optimization of a Stationary Electrode in a Vertically-Driven MEMS Inertial Switch for Extending Contact Duration

Yang

et al. 2017

Sensors

View full text Add to dashboard Cite

show abstract

“…It enabled the size of the switch to be reduced by a substantial amount, giving it a clear edge over conventional switches in automotive safety systems and transportation shock monitoring systems. Recently, a variety of methods, such as carbon nanotube contact pads (Lee, Song, Jung, Choi, Eun & Kim, 2011;, squeeze film effect (Matsunaga & Esashi, 2002) and movable contact pads (Cai, Ding, Yang, Su, Zhou & Wang, 2008), have been adopted in acceleration switches to increase the contact time or 'switch-ON' time; thus providing stability, reliability and easy detection of threshold acceleration. These characteristics are crucial in many commercial applications like airbag restraint systems in transportation and fall detection in the medical industry.…”

Section: Introductionmentioning

confidence: 99%

Sensitivity-Based Reliability Analysis of MEMS Acceleration Switch

Kansal¹,

Kasturi²,

Kim³

et al. 2017

MAS

View full text Add to dashboard Cite

MEMS acceleration switches have been used in many engineering applications. In this paper, the reliability of MEMS switch is evaluated under various uncertainties from materials and manufacturing process. First, the performance of MEMS switch is modeled using 1D mass-spring-damper-contact system. Different from conventional lumped element methods, the model includes the effect of geometric parameters as well as contact conditions. The parameters of 1D models are calibrated using a high-fidelity finite element model. For reliability assessment, four different methods are used in order to compare computational cost as well as accuracy in predicting reliability. It turned out that sensitivity-based reliability method has several benefits, such as computational time and identifying important parameters that contribute significantly to reliability. The sensitivity analysis showed that the cross-sectional height and the length of folded-beam contribute most significantly to the reliability of switch-on condition. After changing the length of the beam, the probability of failure was improved from 0.168 to 0.0003.

show abstract

“…To reduce the contact resistance, some new types of contact points are introduced in the design of the MEMS acceleration switch [26]- [29]. Tadao Matsunaga [30] utilized the squeeze film effect to extend the holding time.…”

Section: Introductionmentioning

confidence: 99%

A Novel Magnetic Actuated Bistable Acceleration Switch With Low Contact Resistance

et al. 2010

View full text Add to dashboard Cite

A novel unsymmetrical bistable mechanism with a parallel beam and three magnets arranged in the three-dimensional space is proposed, and the combined effect of the magnetic force and the mechanical force on the bistability of such a structure is analyzed based on the magnetic-charge model and the material mechanics theory. By employing the nonlinear combined force during the snap-through procedure to enhance the contact force, a novel fast response threshold acceleration switch with low contact resistance is designed and fabricated, which consists mainly of an inertial mass supported by two parallel elastic beams, one metal contact point, and three permanent magnets with one imbedded in the inertial mass and the other two fixed in the case along the vertical direction. The dynamic design model subjected to different shock pulses is proposed to optimize the design process, and the effect of the pulse shapes on the switch's sensing threshold and response time is investigated, and the simulation results show that the acceleration switch is closed in less than 9.0 ms after being triggered by the rectangular shock pulse of amplitude of 50.0 g, and also, the contact force is greater than 0.5 N, which can reduce the contact resistance to an acceptable value and guarantee the contact reliability.According to the working principle of the acceleration switch, a series of test benches are established to test the static and dynamic performance of the switch. The contact resistance is less than 1.9 with a minimum resistance only 0.5 . The average threshold acceleration of the switch sample is 51.4 g with only 2.8% deviation from the design value of 50.0 g. Both the dynamic simulation results and experiments validate the feasibility of introducing permanent magnetic actuated bistable structures in designing the threshold acceleration switch.

show abstract

Design, simulation and fabrication of a novel contact-enhanced MEMS inertial switch with a movable contact point

Cited by 49 publications

References 16 publications

Design and Optimization of a Stationary Electrode in a Vertically-Driven MEMS Inertial Switch for Extending Contact Duration

Design and Optimization of a Stationary Electrode in a Vertically-Driven MEMS Inertial Switch for Extending Contact Duration

Sensitivity-Based Reliability Analysis of MEMS Acceleration Switch

A Novel Magnetic Actuated Bistable Acceleration Switch With Low Contact Resistance

Contact Info

Product

Resources

About