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Materials for photovoltaic neurostimulators based on silicon photodiodes
Kunovský, Ondřej ; Weiter, Martin (oponent) ; Glowacki, Eric Daniel (vedoucí práce)
This thesis is focused on the possibilities of neurostimulators with wireless energy transfer, specifically it explores optical power transfer. Commonly used neurostimulators comprise battery-powered implantable pulse generators, and suffer from the problem of bulky batteries, accounting for more invasive surgery and requirement of periodic replacement. In this work, the alternative of photovoltaic power transfer is explored. Monocrystalline silicon photovoltaic diodes are modified and used as energy transducers. These diodes were cut into different sizes of active surface area, and they were connected into series or parallel connections. These photovoltaic cells were coupled with electrodes made from eight different materials and four different sizes to cover a wide range of possible neurostimulation applications. Next, a prototype photovoltaic stimulator consisting of flexible electrodes and a photovoltaic driver was fabricated. This prototype was successfully tested on small animal models, which they were Hirudo verbena and Locusta migratoria. This work characterizes a range of combinations of individual electrode sizes and materials with photovoltaic diodes for different light intensities and frequencies, creating a map of relevant parameters which can be used to design a prototype stimulator for a specific application. This work lays a foundation for further development of photovoltaic powered neurostimulators to enable novel experiments and one day maybe less invasive clinical devices.
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