Development of Biocompatible MEMS Wireless Capacitive Pressure Sensor

2005 ◽  
Vol 2 (4) ◽  
pp. 287-296
Author(s):  
Shankaran Janardhanan ◽  
Joan. Z. Delalic ◽  
Jeffrey Catchmark ◽  
Dharanipal Saini

The objective of this research was to develop a wireless pressure sensor useful for monitoring bladder pressure. The wireless sensor consists of an active capacitive element and an inductor coil. The changes in pressure are related to the changes in the resonant frequency of the internal sensor. The existing pressure sensors have inductors formed on both sides of the substrate. The changes in internal capacitance of these sensors are related to the changes in pressure by impedance matching of the internal LC circuit. The deviation in bladder pressure is an important variable in evaluating the diseased state of the bladder. The inductor designed for this application is a spirally wound inductor fabricated adjacent to the capacitor. The external sensing uses equivalent changes in internal LC. The resonant frequency of the internal sensor is defined by the deformation of the plate, causing the plate to touch the dielectric on the fixed capacitive plate, which is reflected as changes in capacitance(C). The deformation of the plate has been modeled using Finite Element Analysis. The finite element analysis optimizes the dimensions of the design. Remote sensing is achieved through inductive coupling and the changes in pressure are determined. The device is tested for pressures ranging from 0–150 mmHg, bladder pressure. The RF Telemetry system has been modeled using Sonnet. The frequency range is between 100–670 MHz which is in compliance to that specified by Federal Communications Commission (FCC) regulations.

2019 ◽  
Vol 86 (s1) ◽  
pp. 57-61 ◽  
Author(s):  
Sonia Bradai ◽  
Slim Naifar ◽  
Olfa Kanoun

AbstractHarvesting energy from ambient vibration sources is challenging due to its low characteristic amplitude and frequencies. In this purpose, this work presents a compact hybrid vibration converter based on electromagnetic and magnetoelectric principles working for a frequency bandwidth and under real vibration source properties. The combination of especially these two principles is mainly due to the fact that both converters can use the same changes of the magnetic field for energy harvesting. The converter was investigated using finite element analysis and validated experimentally. Results have shown that a frequency bandwidth up to 12 Hz with a characteristic resonant frequency at 24 Hz and a power density of 0.11mW/cm3 can be reached.


Author(s):  
Yusuke TSUJI ◽  
Yu NAKANO ◽  
Yoshikazu HIRAI ◽  
Ken-ichiro KAMEI ◽  
Toshiyuki TSUCHIYA ◽  
...  

1985 ◽  
Vol 107 (4) ◽  
pp. 375-377 ◽  
Author(s):  
Shen Zhong Han

A sandwich-type plate with metal facings and felt core, fastened by bolts, was studied using both test and finite-element analysis. This type of plate is cheap, light, damping-effective and without pollution; therefore, it is widely used in astronautical engineering. The tests were conducted for different felt thicknesses, bolt numbers, and fastening forces. The results show that the damping depends on friction between the plates and the felt. As compared with an identical stiffness solid plate, the damping of laminated plates can be increased up to 30 times. A mesh with rectangular elements was adopted in the finite-element analysis. In accordance with the slipping mechanism, a rectangular plate clamped on one edge was analyzed with the foregoing elements to determine the resonant frequency and the damping. The difference between the calculated and tested results was within 5 percent for the resonant frequency.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Weili Deng ◽  
Xinjie Huang ◽  
Wenjun Chu ◽  
Yueqi Chen ◽  
Lin Mao ◽  
...  

In order to investigate the interfacial tuning mechanism of electronic skin (e-skin), several models of the capacitive pressure sensors (CPS) with different microstructures and several sizes of microstructures are constructed through finite element analysis method. The simulative pressure response, the sensitivity, and the linearity of the designed CPS show that the sensor with micropyramids has the best performance in all the designed models. The corresponding theoretically predicted sensitivity is as high as 6.3 × 10−7 fF/Pa, which is about 49 times higher than that without any microstructure. Additionally, these further simulative results show that the smaller the ratios ofL/Hof pyramid, the better the sensitivity but the worse the linearity. When the ratio ofL/Hof pyramid is about2, the sensitivity and the linearity could reach a balance point. The simulative results evidently provide the important theoretically directive significance for the further development ofe-skin.


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