MEMS variable stiffness spring and its application in fuze

MEMS processing technology can manufacture any complex structures in a plane, using this point, a variable stiffness design idea for the planar micro-spring is proposed. That is, using one type of structure named contact pairs to achieve stiffness change during the micro-spring’s stretching process. Using contact pairs, three types of variable stiffness springs are designed: stiffness increase spring, stiffness decrease spring and stiffness hump spring. Finally, the variable stiffness springs’ application for fuze setback arming device is discussed. When the three types of springs are used in setback arming device, the stiffness decrease spring is better than the other two springs from security analysis. Kinematic analysis shows that, if the variable stiffness spring’s design is reasonable, the setback arming device not only can effectively solve the safety and reliability issues for rocket fuze, but also applies in small caliber grenade fuze’s working environment without changing the setback arming device’s size and structure. Analysis result indicate that the setback arming device based on MEMS variable stiffness spring is universal for rocket fuze and small caliber grenade fuze.