The Response of a Miniature Scale Cantilever Beam to High-G Impact Stimuli

Abstract

Many contemporary innovations in MEMS devices result from the miniaturization of existing macro-scale systems, exploiting changes in physical phenomena with scale. In terms of a system subject to mechanical stimuli, the response of the system changes significantly as scale decreases: in particular, natural frequencies increase and the system can sustain higher acceleration levels without damage. The objective of this paper is to investigate the response of a miniature scale cantilever beam to high-G impact stimuli in order to gain an understanding of its response. The test model is a machined aluminium cantilever-beam simply supported at one end. The beam cross section is 400 × 200 microns and has lengths of 4mm, 10mm and 20mm. The test bed is an Instron Dynatup 9250HV drop table. The beam response under impact is monitored using an IDT X-Stream XS-4 high-speed camera fitted with a telecentric 10x lenses. Theoretical and computer simulated models using ANSYS and LS-DYNA software are developed and compared with experimentally measured data to verify the accuracy of the techniques used to analyse the structural behaviour of the cantilever beams. The use of high-speed imaging when testing devices for short duration events proves to be beneficial for obtaining several data sets not achievable by post processing techniques.