Executive Summary : | Sensorineural hearing loss is a type of hearing loss where the sensory epithelium along with the basilar membrane is non-functional. At present, this hearing loss or nerve deafness is only treated by Cochlear Implant (CI)surgically. A cochlear implant is an electronic device that restores partial hearing to the deaf. It is surgically implanted in the inner ear and activated by a device worn outside the ear. A major drawback of the system is, the middle and outer ear is bypassed even though it is functioning in most cases. Multichannel Acoustic Nano Biosensor as Artificial Basilar Membrane is the solution proposed in this project when the outer and middle ear is functioning. A patent is granted by the Indian Patent Office on "Flexible Artificial Basilar Epithelium" (No: 359557 granted on 25/02/2021) to the PI and Co-PI submitting this project. The objective of this project is to develop an Artificial Basilar Membrane (ABM) to mimic the functionality of the basilar membrane and testing the model by interfacing with an electronic system. The ABM is a Nano Acoustic Biosensor that works on the principle of piezoelectric acoustic sensor tuned to different audio frequencies ranging from 300 Hz to 4000Hz. The membrane model will be simulated in COMSOL and will be fabricated using a biocompatible polymer with Nano dopants. The developed piezoelectric PVDF films from the electrospinning method will be characterized to evaluate the beta phase of thin-film and will be tested for the functionality of the film as ABM. XRD, FTIR, Raman, AFM, and nanoindentation are the characterization studies that will be carried out to ensure the properties of the thin film. Mechanical stiffness, electrical impedance, and pH measurement will be conducted. The thin films will be tested for various frequencies with LDV testing. A microcontroller-based electronics system will be developed to test the film for various frequencies. From the experiments carried out, 25 pC/N of d33 is obtained and the film is able to generate a voltage of 0.532 v. This piezoelectric property will be enhanced by adding nano dopants to the polymer by setting various process parameters. 20 microW power is required to activate the hair cells with displacement from 30nm to 90 nm. The highlights of the work carried out include the usage of novel dopants using electrospinning to improve the sensitivity that includes Graphene and CNT. A device was fabricated with 20nm displacement for 1KHz frequency, which validates the proof of concept. The electrospinning method adopted is providing us with nanofibers in the range of 30 nm, the lowest diameter of the nanofiber reported in the literature. An Indian patent has been filed on the developed nanofibers. |