MEMS electrical switch has the advantages of small volume and smart response, so it 5-aminosalicylic acid is promising for power supply controlling system application in varied forms. Farrington et al.  proposed a hybrid electrical switch which can deliver significant reductions in switching elements, cabling, cost and power consumption. Chui  put forward MEMS electrical switches used for interferometric modulator, which may form the row or column select functions for the display. Deylitz et al.  invented an electrical switch which includes a locking device. Verma and Kaushik  studied RF MEMS capacitive switch based on a fixed–fixed beam structure, which is designed to achieve low actuation voltage and good reliability. Baghchehsaraei et al.  presented a waveguide SPST switch based on a MEMS reconfigurable surface and its RF performances are superior attributed to the high level of processing circuit integration. Guo et al.  designed a MEMS acceleration switch with an easy-latching/difficult-releasing latching mechanism, in which all the contacts and support beams are separated from the proof mass to prevent the contacts from opening due to the impact resulting from the rebound or vibration once the switch is latched. Kim et al.  devised an acceleration switch capable of increasing the threshold acceleration, in which the comb drive actuators are used in the design to tune the threshold acceleration.
In recent years, MEMS technology also has been integrated closely with advanced weapon system due to the smart requirements for weapon system . Robinson et al. [9–11] proposed a MEMS safety and arming mechanism and carried out the demo launch and ballistic tests. Jing et al. come up with a MEMS safety mechanism of fuze in small caliber rocket round according to the amplitude and duration of acceleration. It can identify the launching environment and perform actions by the Z-shaped teeth, but it is not suitable for the fuze in medium and large caliber ammunition . Liu et al.  designed a MEMS zigzag slot which is applied to the safety and arming mechanism in small caliber projectile fuze of Objective Individual Combat Weapon (OICW), but zone of intolerance cannot be used in the fuze in medium and large caliber projectile.
Device structure and function
The switch proposed in this paper is a mechanical inertial electrical switch. The switch is normally in off-state. It is actuated to be in on-state only when fuze is launched smoothly, while it still holds an off-state in any accidental falling impact. It is designed with the performance of reacting to launching acceleration quickly and reliably. And it also needs to keep the on-state in order to ensure that the power and circuit work continuously. It consists of three parts, a spring–mass system with zigzag slot in mass, a latching and electrical connection mechanism, and a movement-limit mechanism. Fig. 1 shows the structure diagram of the MEMS inertial electrical switch.
The switch has the functions of acceleration response, acceleration amplitude and pulse width recognition, which is actuated by an inertial force. The MEMS spring–mass system is mainly used to detect acceleration undergone by fuze. When fuze is undergoing an acceleration, the mass will be moved. The zigzag slot in mass has damping effect on mass movement, which can be used reasonably to distinguish the fuze launching acceleration from accident falling impact .
The latching and electrical connection mechanism also reacts to acceleration load, and it can be impacted by moving mass. When the latching and electrical connection mechanism transforms from off-state to on-state, it can keep latching by its resilience. The movement-limit mechanism, including side board and stoppers, is used to prevent the proof mass from producing a large lateral jumping and limit the Y-axis displacement of the proof mass.
Model and theoretical analysis
Results and simulation analysis