MEMS Technology for Application

Question: Discuss about the MEMS Technology for Application. Answer: Introduction Cochlea is a part which is inside the ear of the human that transmits the mechanical signal into the electrical signal and further this signal is processed by the brain. Sense cells are located in the basilar membrane which decomposes the mechanical signal into simple frequency components. So in this way, the signal is decomposed mechanically. A dysfunctional cochlea is the reason of the loss of hearing. Cochlea implanting is used to correct this disorder. Cochlea implant is an electronic device that decomposes and transmits the signals into the speech processors. The signal then further transmits to the electrodes by the coil of the innermost part of the implanting. These electrodes are finally connected to the nerves responsible for human hearing. The full implantable cochlear implant constructed for reducing the losses of energy in signals transmitting from outer part to innermost ear. More efficient devices have been investigating that would be replacing the implanting of cochlea r of standard. In these MEMS constructed membrane of thin size with different width along with its entire length for breakdown the acoustic signal is implanted. (Zak, Zdenek, Dusek, Pekarek, Svatos, Janak, Prasek, 2015) Approach and Methodology The completely implantable cochlear implanting is the fundamental base of an acoustic signal detection which is located at the inside of the middle of the ear space. This is further connected to the ear drum by some middle ear prosthesis. This type of implanting is designed as MEMS sensors arranged in array. This includes a number of active membranes along with elements of piezoelectric that are made up in the frequency range of hearing by human. (Liu, 2005) Sensing system which is the array made of the electromechanical filters works for the detection of acoustic frequency which is dominant. The acoustic wave actuated the MEMS sensors are propagating by the vibration of the prosthesis in the middle ear. This propagation of waves are look like to the cochlea which is inside of the human ear. ( Conde, Gaspar, chu,2003,) The cochlear implanting is fabricated as the array of piezoelectric membranes which having the different width for achieving different values of Eigen frequencies. The piezoelectric element senses the vibration of the membranes and which act as an active sensor to decompose the excited feed acoustic signals. This has great benefits over the common speech system which is an energetically costly mathematical decomposition of the acoustic signal. Our design use the fluid medium for transferring the pressure to the MEMS sensors through the middle ear just like the human ear biomechanics. The MEMS sensors represent the each and every mechanical filter which is consists of a SixNy square membrane with four piezoelectric AIN elements placed at the edge of the membrane. Usually the cochlear implants used are in the range of twelve to twenty four channels but in improve design of the MEMS cochlear implantation has twenty four active MEMS sensors. 2 measurement methods are used for the characterization of acoustic sensor. The 1st real eign frequency was calculated by the first method and the deformation of the diaphragm was driven by the vibration table in the measurement. (Sze, 1981) Results and discussion For the analysis of the mechanical membrane having the layer of piezoelectric and behavior electrodes, the modal in ANSYS environment is used. Both the output electrical signal and dynamic of membrane are calculated. The 1st eign frequencies of resonant membrane with various dimensions are calculated in ANSYS and CoventorWare. The Covent or Ware are not for the analysis of interaction of the acoustic fluid structure with silicon oil that is being used for implant. The calculation also includes the edge membranes that are fixed. The result calculated in the finite elements analysis ANSYS and CoventorWare is shown in the table. The lowest eignfrequency is 1kHz and 7 kHz for the smallest and largest membrane respectively. The range in between 1 kHz to 4kHz is very sensitive for the human ear. So the dimensions of resonant membrane should be in between 2x2 mm and 1x1 mm. (DUSEK, HADAS, Pekarek, Svatos, Jaromir, Prasek, Hubalek, 2015) Figures and Tables Schematic of the cochlea signal processing electronics (DUSEK, HADAS, Pekarek, Svatos, Jaromir, Prasek, Hubalek, 2015) The workplace setup for MEMS sensor measurement during acoustic stimulation (Svatos, Pekarek, Dusek, Zak, Hadas, Prasek, 2014) Eigen frequencies calculated in Ansys Conventor Ware for resonant diaphagrams with different dimensions (DUSEK, HADAS, Pekarek, Svatos, Jaromir, Prasek, Hubalek, 2015) Comparison of data measured by vibration and acoustic driven method (Svatos, Pekarek, Dusek, Zak, Hadas, Prasek, 2014) Conclusions The thin film membrane sensor is rely on the silicon germanium boron was characterized, fabricated for the potential of the application for pressure variations. At low deposition temperature, the fabrication is done to accomplish the reliability silicon technology. The Prototype model of a-SiGeB sensor will be used as an innovative cochlear implant of a simple sensor design. The electrical characterization had shown that a-SiGe: B films are very suitable for this sensor with its reads out electronics circuit due to its less resistivity. Thus, the device presented a good sensitivity compared with other piezo-resistive strain sensors. (Heredia, Ambrosio, Moreno, Zuniga, Jimenez, Monfil, Hidalga, 2012) References Liu C., 2005,Foundation of MEMS, chapter 6, Prentice hall, USA, Accessed 19 April 2017 Conde J.P., Gaspar J., chu V.,2003, thin solid films 427 ,181-186, Accessed 19 April 2017 Sze S.M., 1981, Physics of Semiconductor Devices, John Wiley and sons, USA , Accessed 19 April 2017 Heredia. A, Ambrosio. R, Moreno. M, Zuniga. C, Jimenez. A, Monfil. K, Hidalga. J, 2012, Thin film membrane based on a SiGe: B and MEMS technology for application in cochlear implants, Journal of Non-Crystalline Solids, Elsevire, Accessed 19 April 2017 Zak. J, Zdenek. H, Dusek. D, Pekarek. J, Svatos. V, Janak. L, Prasek. J, 2015,Model based design of artificial zero power cochlear implant, Mechatronics, Elsevier, Accessed 19 April 2017 DUSEK. D, HADAS. Z, Pekarek. J, Svatos. V, Jaromir. Z, Prasek. J, Hubalek. J, 2015, Design of an Artificial Micro electro mechanical Cochlea, Central European Institute of Technology, Bmo University of Technology, Technocka 10, ISSN: 1662-9779, Vols. 220-221, pp 345-348, Accessed 19 April 2017 Svatos. V, Pekarek. J, Dusek. D, Zak. J, Hadas. Z, Prasek. J, 2014, Design and fabrication of fully implantable MEMS Cochlea, 5th DAAAM International Symposium on Intelligent Manufacturing and Automation, DAAAM, Science direct, Proccedia Engineering 100 (2015) 1224-1231, Accessed 19 April 2017