Parametrically excited structures are now extensively used in many fields of science and technology, especially in micro- and nanoscale applications. Term “parametric” implies that the excitation affects certain parameters of the structure, e.g. its stiffness, damping, or mass properties. This type of excitation can lead to relatively large vibration amplitudes of structures and many micro- and nanoscale sensors, amplifiers, and energy harvesters utilize it. Recently, it has been shown that employing parametric amplification, i.e. combining parametric excitation with the conventional direct excitation, can lead to even larger output vibration amplitudes. The present project concerns analysis of this phenomenon for a model micro electromechanical structure, e.g. a beam between two stationary electrodes. Direct excitation will be induced by applying an alternating voltage between the beam and the electrodes. Parametric excitation will be induced by a varying longitudinal force in the beam.
It is intended to study both experimentally and theoretically the response of the beam to the excitations and determine values of the parameters at which the maximum output can be achieved. Possible effects of frequency detuning between the excitations as well as of structural nonlinearity on the beam response are to be studied.
Undergraduate
Manufactured model micro electromechanical structure featuring combined direct and parametric excitations.
Values of parameters at which maximum vibration amplitudes can be achieved
Basic knowledge of electrical theory and dynamics and vibration theory.
Some experience with experimental testing of electromechanical systems is advantageous.
Microfabrication Lab (201.406B and 201.406, Lab)