MEMS Safety Arming Device Raised Pattern Substrate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Adhesion phenomena between thick parts in micro-electro-mechanical systems (MEMS) safety and arming devices for projectiles hinder optimal and reliable functioning due to strong adhesion between plane surfaces, particularly when the mobile element is in contact with the MEMS substrate, affecting the isolation between the detonator and explosive load.
Innovation Solution
The implementation of raised patterns on the substrate layers, such as rails or studs, to reduce contact surfaces and friction between the mobile part and the substrate, ensuring the mobile part is always held immobile between these patterns, thereby minimizing adhesion and ensuring smooth movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thick barrier parts are used in MEMS safety and arming devices, then the isolation between detonator and explosive load is improved, but adhesion between plane surfaces increases hindering relative movements
Solution Approach 1:
The barrier is segmented into a mobile element and stationary substrate, with the mobile element divided into multiple segments that move independently. This segmentation reduces the contact area between the mobile element and substrate, thereby reducing adhesion forces while maintaining the barrier's isolation function.
Solution Approach 2:
The invention transitions from a planar contact interface to a three-dimensional configuration where the mobile element is supported by vertical pillars. This dimensional change reduces the contact surface from a large area to discrete point contacts at the pillar tops, significantly reducing adhesion while maintaining structural integrity.
2Ease of manufacture
If plane surfaces are used for the barrier and substrate contact, then the manufacturing is simplified, but adhesion and friction between surfaces increases
Solution Approach 1:
The contact surfaces are changed from flat plane surfaces to curved spherical or hemispherical surfaces. The mobile element features curved contact areas that reduce adhesion and friction compared to flat surfaces, while still being manufacturable using standard MEMS fabrication processes.
Solution Approach 2:
Vertical pillars or fingers act as intermediary structures between the mobile element and substrate. These intermediaries reduce the direct contact area between the mobile element's bottom surface and the substrate, thereby reducing adhesion and friction while maintaining structural support.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design significantly reduces friction and adhesion, ensuring reliable and safe operation of the safety and arming device by maintaining the mobile part's position between raised patterns on the bottom and top layers, enhancing the device's functionality and performance at the MEMS scale.
Implementation Method 1
The phenomena of adhesion for thick parts becomes determining. At the MEMS scale, two plane surfaces brought into contact with one another adhere to one another relatively strongly thereby hindering relative movements in these planes.
Implementation Method 2
The proposed solution consists in strongly reducing the contact surfaces between the barrier and other mobile elements of the SAD that are in contact with the surfaces of the substrate.
Data Source
AI summary
The invention consists of a safety and arming device for a projectile and using micro electro-mechanical technology that incorporates at least three layers of substrate: a bottom, a top and at least one intermediate layer incorporating at least one mobile part with respect to the different layers of substrate wherein the bottom and top incorporate raised patterns, the raised patterns being evenly spaced over the bottom and the top such that the mobile part is always, when in movement, held immobile between the raised patterns of the bottom and those of the top, the raised patterns of the bottom being in contact with a lower face of the mobile part and the raised patterns of the top being in contact with an upper face of the mobile part.