PhD Thesis, Maria del Carmen Fuentes Dubra
Maria del Carmen Fuentes Dubra
Title: BioMEMS-Based Microfabrication Processes for Manufacturing Flat Flexible Microelectrode Arrays for Atraumatic Cochlear Implantation
Defense Date: 3/06/2019
Director: Isabel Ayerdi
Nowadays, commercial cochlear electrodes consist in handcrafted rigid wires. However, new electrode designs are emerging focusing on depth of insertion, flexibility and size of the electrode to ensure reliable and full atraumatic insertions, a great challenge of each cochlear implantation. Flexibility can ensure structure preservation, preservation of low-frequency hearing and the inclusion of subjects with less severe auditory pathologies to use this very successful rehabilitation treatment. Flexible cochlear electrodes reduces the insertion forces preserving the cochlear structure to keep also future new therapies viable which can be especially important for implanted children.
The proposed new electrode design replaces the bundles of wires by a flexible thin film microelectrode array to minimise insertion damage. In addition, microsystem technology can be used for manufacturing which allow also automation of the manufacturing process, increased reproducibility and reduced fabrication costs.
Developed microstructuring and metallisation processes allow to manufacture flat, flexible and biocompatible microelectrode arrays according to the dimensional requirements of the human cochlea. Electrical and mechanical behaviour show feasibility and reliability of flexible thin film microelectrodes and further potential for a new generation of atraumatic cochlear electrodes. Furthermore, the technical realisation of the electrode design offers the possibility to easily and cheaply adapt the manufacturing process to the dimensional requirements of electrodes for other neural implants