PhD Thesis Proposal: Tianyu Bai

"Advanced Packaging Strategies for High-Density Flexible Neural Interfaces"

Abstract

Next-generation neural interfaces are critical for decoding complex brain function and enabling advanced brain–computer interfaces. These systems increasingly require high channel density, long-term stability, and multimodal sensing capabilities. Despite recent progress in soft microelectrode arrays (MEAs), two fundamental engineering challenges limit their chronic deployment. First, interfacing soft, high-density thin-film electrodes with rigid signal-processing electronics creates a mechanically fragile soft–hard interface. Conventional rigid connectors impose high insertion forces, strict alignment requirements, and bulky form factors, often leading to premature mechanical failure. Second, concurrent dual-modal sensing—specifically fast-scan cyclic voltammetry (FSCV) alongside electrophysiological recording—introduces severe electrical crosstalk, where large-amplitude FSCV currents overwhelm microvolt-level neural signals. To address these challenges, we present E-Link, an open-source, modular 256-channel mini-pedestal connector that employs an elastomeric conductive interposer and a compliant threaded compression mechanism for insertion-free assembly. The system is characterized in terms of contact impedance, mechanical durability, and thermal stability. In addition, we introduce a novel 3D microfabricated shielding wall (μWall) architecture that confines FSCV-induced interference and enables artifact-free dual-modal neural recording. Collectively, these packaging and microfabrication strategies provide a scalable framework for high-channel-count neural interfaces and advance the deployment of next-generation neural implants.

Thesis Committee

Hui Fang (Chair), Wei Ouyang, Peter Chin, and Yaoyao Jia (The University of Texas at Austin)

Contact

For more information, contact Thayer Registrar at thayer.registrar@dartmouth.edu.