Optimization of Capacitive Acoustic Resonant Sensor Using Numerical Simulation and Design of Experiment

Abstract

Optimization of the acoustic resonant sensor requires a clear understanding of how the output responses of the sensor are affected by the variation of different factors. During this work, output responses of a capacitive acoustic transducer, such as membrane displacement, quality factor, and capacitance variation, are considered to evaluate the sensor design. The six device parameters taken into consideration are membrane radius, backplate radius, cavity height, air gap, membrane tension, and membrane thickness. The effects of factors on the output responses of the transducer are investigated using an integrated methodology that combines numerical simulation and design of experiments (DOE). A series of numerical experiments are conducted to obtain output responses for different combinations of device parameters using finite element methods (FEM). Response surface method is used to identify the significant factors and to develop the empirical models for the output responses. Finally, these results are utilized to calculate the optimum device parameters using multi-criteria optimization with desirability function. Thereafter, the validating experiments are designed and deployed using the numerical simulation to crosscheck the responses.

Fabrication of Capacitive Acoustic Resonators Combining 3D Printing and 2D Inkjet Printing Techniques

“…Finally, the experimental observation is compared to the numerical result performed using COMSOL Multiphysics software. For details about numerical model building see [ 5 ].…”

“…In addition, the sensor should have selectivity with a Q-factor above 25 at its first resonance frequency. Haque et al [ 5 ] have presented the optimum range of parameters for the design that will satisfy the device requirements. According to the study, the best optimum set of parameters are a membrane radius of 8.1 mm, backplate radius of 871 µm, cavity height of around 3987 µm and air gap of around 80 µm and membrane thickness of 19.8 µm along with a membrane tension of 2158 N/m.…”

“…The capacitance variation (∆ C ) of the capacitive transducer can be expressed as: where C i represents the static capacitance of the transducer, h g is the air gap under an applied external DC potential and <ξ> Se represents the average small signal deformation of the effective membrane. For details see [ 5 ].…”

“…In recent times, to fulfill the industrial requirement of a cost efficient printed capacitive acoustic sensor having the proper sensitivity and selectivity to develop highly integrated RFID solutions [ 2 ], a new design to fabricate capacitive acoustic transducer has been proposed ( Figure 1 ) [ 3 , 4 ], which can also be used to fabricate capacitive acoustic resonant sensors with adequate selectivity and selectivity, as described by Haque et al [ 5 ].…”

Inkjet-Printed Membrane for a Capacitive Acoustic Sensor: Development and Characterization Using Laser Vibrometer

“…Recently, a new concept of fabricating a capacitive acoustic resonator has been presented using the inkjet printing technique [ 4 ]. To achieve good sensitivity and selectivity of the capacitive resonator, combining numerical simulation and design of experiment [ 24 ], optimization of six device parameters, namely membrane radius, back plate radius, cavity height, air gap, membrane tension and membrane thickness, is required. Amongst them, membrane tension is one of the most important parameters to tune the resonator.…”