Interfacing Neuronal Tissue with 3D Electrodes

Neuronal signals obtained from 3D neural tissue using various - in vitro or in vivo - approaches lack the spatial resolution and high signal-to-noise ratio (SNR) required for a detailed understanding of neural network function and synaptic plasticity. To overcome these limitations, we used a highly customizable 3D printing process in combination with thin film technology and templated assisted electrodeposition to fabricate 3D-printed based microelectrode arrays on stiff and flexible substrates. We show devices with design flexibility and physical robustness for recording neural activity in different in vitro and in vivo applications: our microelectrode arrays successfully recorded neural activity in 3D neuronal cultures, retinal explants, and the cortex of living mice, thereby demonstrating the versatility of the 3D microelectrode platform while maintaining high-quality neural recordings. Customizable 3D microelectrode arrays provide unique opportunities to study neural activity under regular or various pathological conditions, both in vitro and in vivo, and contribute to the development of drug screening and neuromodulation systems that can accurately monitor the activity of large neural networks over time.