One-Step Laser-Induced Dissolvable PVA Mask for 3D Soft Carbon Electrode Array

This paper introduces a 3D soft carbon electrode array, fabricated through a one-step laser-induced process integrating a water-dissolvable polyvinyl alcohol (PVA) mask. This approach achieves precise conical microstructures and robust conductive channels using hybrid MWCNT@PDMS conductive paste. The soft carbon electrode sites with a 3D conical microstructure are designed to enhance proximity to neural tissue, thereby enhancing electrocorticogram (ECoG) signal quality and enabling effective neural stimulation. The electrode array demonstrates remarkable stretchability (25% over 1,000 cycles without failure) and stability (equivalent to 66 days in vivo). Compared to conventional materials, our electrodes exhibit superior electrochemical properties, including lower impedance (9.7 kΩ at 1 kHz) and higher signal-to-noise ratio (SNR, 61.7 dB). Thus, this one-step process is a cost-effective, scalable solution for recording and modulating central or peripheral neural tissues.