Vibration Analysis Of Electrically Excited Microbeams Under Non-Ideal Boundary Conditions
by
Hakan Boyaci
Celal Bayar University, Department of Mechanical Engineering, 45140 Muradiye-Manisa, Turkey
Coauthors: H.Onur Ekici, Celal Bayar University, Department of Mechanical Engineering, 45140 Muradiye-Manisa, Turkey; onur.ekici@bayar.edu.tr

Microbeam models used in MEMS applications have many advantages. Weight and inertia forces become negligible at micro-scale, so it becomes possible to manufacture sensors resistant to high accelerations and high frequency switches.

In analysis of electrically driven microbeam models ideal boundary conditions have been employed and solutions have been obtained accordingly till now. But there are always small deviations from ideal conditions. Non-ideal boundary conditions mentioned here refer to deflections and/or moments which do not meet ideal values. Various axial strains acting on microbeam and non-ideal boundary conditions cause changes on frequencies. While minor changes in ideal boundary conditions for normal beams cause deviations on frequency-response curves, more apparent deviations are expected for sensitive microbeams.

Microbeams can be excited in various ways. In our analysis it was assumed that microbeam had been electrically excited. Also stretching effects because of axially unmovable boundary conditions were accounted during vibration of microbeam. Primary resonance behavior of electrically excited microbeam was investigated by Multiple Time Scale Method, a perturbation technique. Phase-modulation equations were derived and using these equations frequency-response graphs were contrasted. It was seen on these graphs that there had been significant deviations caused by non-ideal boundary conditions with respect to ideal cases.

Keywords : microbeam vibrations, electrically excited microbeams, non-ideal boundary conditions, method of multiple time scales

Date received: February 16, 2007