Acoustic Fresnel lens to focus ultrasound for in vitro neuromodulation

Abstract

In vitro neuromodulation studies play a crucial role in understanding the underlying interaction mechanisms between cells and ultrasound, which is important in the development of new therapies for various neurological disorders. Acoustic focusing, the ability to focus ultrasound at a specific focal length with high spatial resolution, provides a precise and effective way to stimulate cell cultures. In this way, researchers are able to stimulate specific cells or regions within a cell culture, leading to a better understanding of cellular behaviour and responses to ultrasound stimulation.

This thesis focuses on designing and developing a microfabricated acoustic Fresnel lens to focus ultrasound at a pre-determined focal length to fit into currently used Microelectrode Array (MEA) devices. Polydimethylsiloxane (PDMS) is used as lens material and microfabrication technologies are employed for the fabrication of a silicon mold. Experimental measurements have been conducted in an underwater configuration to evaluate the performance of the acoustic lens. The research highlights the potential of using acoustic Fresnel lenses on ultrasound transducers for in vitro neuromodulation. The results of the study demonstrate their capability to effectively focus ultrasound waves at the desired focal length. This advancement has significant implications for the field of in vitro neuromodulation, as it offers a cost-effective and promising method for achieving more accurate stimulation of cell cultures and for studying the impact of various acoustic parameters on cells.