A laterally-driven micromachined inertial switch with a compliant cantilever beam as the stationary electrode for prolonging contact time

A novel inertial micro-switch with polymer-metal composite fixed electrode has been designed based on non-silicon surface micromachining technology. The micro-switch can sense the applied accelerations from positive z-axis. It can realize a flexible contact between the electrodes, eliminate the bouncing phenomenon and prolong the contact time. The dynamic contact simulation of the micro-switch has been implemented under the half-sine wave shock with 80g peak value, and its vertical response time is about ~80μs.

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The Design, Simulation and Fabrication of an Omnidirectional Inertial Switch with Rectangular Suspension Spring

Micromachines ◽

10.3390/mi12040440 ◽

2021 ◽

Vol 12 (4) ◽

pp. 440

Author(s):

Wenguo Chen ◽

Rui Wang ◽

Huiying Wang ◽

Shulei Sun

Keyword(s):

Dynamic Response ◽

Contact Time ◽

Horizontal Direction ◽

Suspension Spring ◽

Threshold Distribution ◽

Spring Suspension ◽

Coupling Stiffness ◽

Inertial Switch ◽

High Consistency ◽

Sensitive Direction

An omnidirectional inertial switch with rectangular spring is proposed in this paper, and the prototype has been fabricated by surface micromachining technology. To evaluate the threshold consistency and stability of omnidirectional inertia switch, the stiffness of rectangular suspension springs is analyzed. The simulation result shows that the coupling stiffness of the rectangular spring suspension system in the non-sensitive direction is a little more than that in the sensitive direction, which indicated that the omnidirectional switching system’s stability is reinforced, attributed to the design of rectangular springs. The dynamic response simulation shows that the threshold of the omnidirectional inertial switch using the rectangular suspension spring has high consistency in the horizontal direction. The prototype of an inertial switch is fabricated and tested successfully. The testing results indicate even threshold distribution in the horizontal direction. The threshold acceleration of the designed inertial switch is about 58 g in the X direction and 37 g in the Z direction; the contact time is about 18 μs.

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Simulation and Experiment of a MEMS Omnidirectional Inertial Switch

Volume 10: Micro- and Nano-Systems Engineering and Packaging ◽

10.1115/imece2014-39737 ◽

2014 ◽

Author(s):

Y. Cao ◽

J. Wang ◽

Z. W. Xi ◽

W. R. Nie ◽

X. J. Wang ◽

...

Keyword(s):

Contact Time ◽

Threshold Value ◽

Shock Acceleration ◽

Test Device ◽

Fe Method ◽

Shock Test ◽

Simulation And Experiment ◽

Spring System ◽

Inertial Switch ◽

Mass Spring

A MEMS omnidirectional inertial switch was designed and fabricated based on non-silicon surface micromachining technology. The switch consists of mass-spring system, flexible radial electrodes and axial electrode. It has omnidirectional sensitivities in a half sphere. The modal analysis of the switch was performed. The system stiffness of the mass-spring system and the response displacement of the mass in all directions under the applied shock acceleration of 450g was obtained by using the FE method, as a result, the switch has good omnidirectional performance and small distributed threshold acceleration. The fabricated switches were tested by a shock test device. The results show that the threshold acceleration of the switches is within the range of 270g to 450g. As an acceleration exceeding the threshold value acting along the X-axis or Z-axis, the switch can be reliably closed and have a long contact time.

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A surface-micromachining-based inertial micro-switch with compliant cantilever beam as movable electrode for enduring high shock and prolonging contact time

Applied Surface Science ◽

10.1016/j.apsusc.2016.06.164 ◽

2016 ◽

Vol 387 ◽

pp. 569-580 ◽

Cited By ~ 13

Author(s):

Qiu Xu ◽

Zhuoqing Yang ◽

Bo Fu ◽

Jianhua Li ◽

Hao Wu ◽

...

Keyword(s):

Cantilever Beam ◽

Contact Time ◽

Surface Micromachining ◽

Movable Electrode ◽

High Shock

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Analysis of Closure Characteristics of a MEMS Omnidirectional Inertial Switch under Shock Loads

Shock and Vibration ◽

10.1155/2015/604047 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Yun Cao ◽

Zhanwen Xi ◽

Jiong Wang ◽

Weirong Nie

Keyword(s):

Contact Time ◽

Theoretical Method ◽

Dynamic Contact ◽

Shock Acceleration ◽

Fe Method ◽

Prolonged Contact ◽

Spring System ◽

Inertial Switch ◽

Mass Spring ◽

Theoretical Results

A preliminary theoretical method for calculating contact time of a dual mass-spring system applied to shock acceleration was proposed based on the MEMS omnidirectional inertial switch. The influence of relevant parameters on the contact time was analyzed, and the theoretical results were in agreement with the simulation predictions. The theoretical method could provide the design of MEMS inertial switch for prolonged contact time. The system stiffness of the mass-spring system in all directions was obtained by using the FE method. Dynamic contact simulation results of contact time in typical directions under the applied shock acceleration indicate that the switch has a contact time within the range of 33 μs to 95 μs and has an enhanced contact effect with the dual mass-spring system in the MEMS inertial switch. The fabricated switches were tested by a shock test device. The results show that the switch can be reliably closed in all directions under the applied shock acceleration and has a long contact time, which is basically in accordance with the theoretical results.

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The Elastic Contact and Stability Analysis of an Inertial Micro-Switch with a Spring Stationary Electrode

Sensors ◽

10.3390/s18124238 ◽

2018 ◽

Vol 18 (12) ◽

pp. 4238

Author(s):

Wenguo Chen ◽

Huiying Wang ◽

Dejian Kong ◽

Shulei Sun

Keyword(s):

Finite Element ◽

Contact Time ◽

Contact Process ◽

Experimental Tests ◽

Element Model ◽

Elastic Contact ◽

Element Analysis ◽

Stability Performance ◽

High Acceleration ◽

Stationary Electrode

A mechanical trigger inertial micro-switch with spring stationary electrode is proposed and fabricated by surface micromachining. The elastic contact process and stability performance are evaluated through experimental tests performed using a drop hammer. The test results show that the contact time is about 110 μs and 100 μs when the threshold acceleration is 480 g and the overload acceleration is 602 g, respectively. The vibration process of the electrodes is explained through an established physical mode. The elastic contact process is analyzed and discussed by Finite Element Analysis (FEA) simulations, which indicated that the contact time is about 65 μs when the threshold acceleration is 600 g. At the same time, this result also proved that the contact time could be extended effectively by the designed spring stationary electrode. The overload acceleration (800 g) has been applied to the Finite-Element model in ANSYS, the contact process indicated that the proof mass contacted with stationary electrode three times, and there was no bounce phenomenon during contact process, which fully proved that the stable contact process can be realized at high acceleration owing to the designed elastic stationary electrode.

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