Breaking the Dimension Barrier: Varidepth Neuroelectrode Array (VD-NEA) Enabled by a Novel Stereo Mask for Achieving Arbitrary Electrode Depth in Neural Recording

Implantable neural electrodes are crucial in neuroscience, clinical diagnosis, and human-machine interaction. However, current electrodes face challenges in achieving true 3D neural activity acquisition due to limitations in electrode point distribution. This paper presents the VariDepth Neuroelectrode Array (VD-NEA), a novel microelectrode array utilizing an innovative stereo-mask to achieve customizable arbitrary electrode depth distribution. Using projection microstereolithography (PμSL), microneedle arrays and stereo-masks were fabricated with customizable height distributions, demonstrating excellent fabrication stability and impedance consistency across different electrode heights. Implant experiments successfully recorded local field potentials (LFPs), highlighting superior spatial resolution and 3D recording capabilities. By overcoming the dimensional limitations of traditional arrays, VD-NEA offers flexible electrode placement tailored to the cerebral cortex’s complex structure, significantly enhancing neural signal accuracy and coverage. This innovation holds promise for advancing neuroscience research.