Microfibrous Mesh and Polymer Damping of Micromachined Vibration Isolators

This article introduces the use of nickel (Ni) and copper (Cu) microfibrous meshes (MFMs) and Sorbothane and polydimethylsiloxane (PDMS) viscoelastic polymers to damp the dynamic response of a silicon micromachined vibration isolator (microisolator) for vibration reliability in mechanically harsh environments. The 9\times 9 mm 2 microisolator is designed to house a small, packaged MEMS sensor to be isolated from the surrounding environment. Microisolators are fabricated from \langle 100\rangle silicon-on-insulator (SOI) wafers using standard lithography and deep reactive ion etching (DRIE) procedures. The MFMs are attached to the microisolators post-fabrication via solder attachment. We then investigate the transmissibility of the undamped and damped vibration microisolators using laser Doppler vibrometry. The peak transmissibility of the microisolator is significantly reduced for all four cases of polymer or MFM damping. Experimental results are compared to the FEA simulated transmissibility and the analytically calculated transmissibility.