Failures on MEMS microphones placed on dummy smartphone are observed during a guided free fall test. The instants before and after the first impact are registered with a high-speed camera and the displacement/velocity signals are used as input for three-dimensional finite element analyses at different scales to obtain insights at local level to judge whether possible ruptures arise. The numerical procedure follows a multi-scale, top-down approach and it can adopt both fluid-structure interaction and purely mechanical analyses. Finally, two loadings are transferred at the micro-scale to the thin silicon membrane representing the microphone: it is found that, in some drop cases, failures depend from the combination of the fluid-induced (air over-pressure) and of the solid-induced input (relative displacements at the anchors), and not from a single domain loading condition.

在引导式自由落体测试期间，会观察到放置在虚拟智能手机上的MEMS麦克风出现故障。用高速摄像机记录第一次撞击之前和之后的瞬间，并将位移/速度信号用作不同比例的三维有限元分析的输入，以获取本地的见解，以判断是否可能发生破裂。数值过程遵循多尺度，自上而下的方法，可以同时进行流固耦合和纯机械分析。最后，两个载荷在微观尺度上传递到代表麦克风的硅薄膜上：发现在某些跌落情况下，失效取决于流体引起的（空气超压）和固体的结合。引起的输入（锚点处的相对位移），