Flexible intracortical probes for stable neural recording: from the perspective of structure

Electrical neural interfaces provide direct communication pathways between living brain tissue and engineered devices to understand brain function. However, conventional neural probes have remained limited in providing stable, long-lasting recordings because of large mechanical and structural mismatches with respect to brain tissue. The development of flexible probes provides a promising approach to tackle these challenges. In this review, various structural designs of flexible intracortical probes for promoting long-term neural integration, including thin film filament and mesh probe structures that provide similar geometric and mechanical properties to brain tissue and self-deployable probe structure that enables moving the functional sensors away from the insertion trauma, are summarized, highlighting the important role of structural design in improving the long-term recording stability of neural probes.