Lithium Niobate-based virtual microelectrods for neurons optical stimulation: a feasibility study

This thesis explores a novel technique at the intersection of materials science and neuroscience, focusing on the use of Lithium Niobate (LN) to advance neuron stimulation methods. The primary goal is to reduce unwanted effects when using light to influence biological matter, offering a new way to stimulate neurons in their natural state. This research is preliminary and serves as a feasibility study, but it sets the stage for future developments in understanding and treating neurodegenerative diseases. Neurodegenerative diseases are often linked to problems in how neurons generate and transmit signals. Effective treatment and a better understanding of these diseases require accurate models of neural signal transmission. Current techniques, such as patch clamping and optogenetics, are valuable but have limitations. They can be invasive, and there's often a mismatch between neuron growth and electrode placement. The PRIN22 project ASSONE aims to develop a new platform that allows neurons to be stimulated "as they are," using electrical fields tailored to their natural structures. This thesis contributes to the early stages of this project by designing and building two specialized devices. The first is a light generator that leverages the Bulk Photovoltaic Effect (BPVE) in LN, integrated into an electrophysiology microscope for precise light delivery in experiments. The second is a reconfigurable optical microscope that supports various imaging techniques and includes another BPVE light generator. These tools will enable advanced studies on BPVE and its potential for neuron stimulation. In the later stages, the thesis focuses on measuring the BPVE in different LN samples by observing the forces acting on microparticles placed on the LN surface. The final part of the research explores how Virtual MicroElectrodes (VMEs) created by the BPVE can be used to stimulate neurons. Although this work is exploratory, it provides a solid foundation for future research in neuroscience and materials science.