Posters

CHARACTERIZATION OF TRANSIENT FIELDS AROUND ARBITRARILY SHAPED ORGANIC ELECTROLYTIC PHOTOCAPACITOR DEVICES

Anja Mioković1, Aleksandar Opančar1, Marta Nikić1, Vedran Đerek1

1Department of Physics, Faculty of Science, University of Zagreb, Zagreb, Croatia

Electrical neurostimulation is the targeted excitation of the neurons or parts of the central nervous system by electric field, with a well-defined therapeutic goal. Organic electrolytic photocapacitors (OEPC) are recently developed opto-bioelectronic devices based on organic semiconductors, with the purpose of capacitive and non-Faradaic neurostimulation. The absence of electrochemical Faradaic reactions on electrodes avoids the generation of free radicals and metal ions near the bioelectronic implant. For safe and efficient capacitive neurostimulation it is desirable to spatially limit its effect to the target area and limit unwanted current flow through sensitive areas of tissue. When choosing the geometry of a stimulating electrode, it is necessary to understand the spatial propagation of the electric field around it. In our laboratory, we have assembled an experimental setup which allows direct measurement of the transient potential in the electrolyte above a photocapacitor illuminated by pulsed light. By analyzing the measured 3D potential maps, a 3D electric field map can be determined. We will describe the architecture of the setup, possibilities, and limitations of measurement, and present the obtained results for some simple shapes of photocapacitors.

Acknowledgements: This work has been supported by the Croatian Science Foundation under the project 3Doptobio UIP-2019-04-1753 and the project CeNIKS, co-financed by the Croatian Government and the European Union through the European Regional Development Fund – Competitiveness and Cohesion Operational Programme (grant no. KK.01.1.1.02.0013), and the QuantiXLie Center of Excellence, a project co-financed by the Croatian Government and European Union through the European Regional Development Fund – the Competitiveness and Cohesion Operational Programme (grant no. KK.01.1.1.01.0004). Financial support by the Center of Excellence for Advanced Materials and Sensors, Croatia, is gratefully acknowledged.

Presenting author e-mail address: anja.miokovic@student.pmf.hr