APOLLO: Acoustic Powering of Light-based Linked Opto-stimulators

Abstract

Neurostimulation has emerged as a transformative approach for the treatment and management of a broad range of neurological disorders, including depression and epilepsy. The increase in usage of neurostimulation also necessitates high spatial resolution and depth of penetration in order to inflict minimal damage to the surrounding tissue. Optical or light-based stimulation offers unique benefits in this regard, enabling highly spatially resolved neural activation and paving the way for innovative modalities in targeted neural modulation.
In this work, an electronic platform for wireless powering and data transmission is presented,
utilising organic P–N junctions as the core technology for mediating photo-electric stimulation. These junctions are selected for their capacity to provide non-genetic neural activation with excellent spatial resolution. Power delivery to the implantable device is achieved acoustically via ultrasound, taking advantage of ultrasound’s superior tissue penetration characteristics.
Comprehensive characterisation of the organic P–N junctions was performed, culminating in
the identification of the PDCBT/ITIC architecture as the most suitable P-N junction, based on its
favourable optical absorption profile and photocurrent generation capability. In parallel, a dedicated power management and stimulation platform was developed as the initial steps in incorporating acoustic energy harvesting and efficient signal demodulation. Validation experiments confirmed reliable device performance and established a functional basis for wireless optoelectronic neurostimulation.
The results of this thesis establish a promising system-level paradigm for minimally invasive,
wirelessly powered neurostimulation using organic photo-sensitive interfaces and acoustic power links. This approach contributes a viable pathway toward the development of next-generation neural therapies with enhanced implantability.