Fully-Flexible Multifunctional Polydimethylsiloxane (PDMS) Neural Probe With a U-Turn Polyester Microchannel

作者：Akram MM, Aghajani A, Levesque J, Fontaine R, Nabki F, Shi W, Gosselin B · 发表于：IEEE transactions on bio-medical engineering · 年份：2026 · DOI：10.1109/tbme.2025.3641990 · 研究领域：Dimethylpolysiloxanes、Polyesters、Microfluidic Analytical Techniques、Electrodes, Implanted、Drug Delivery Systems、Animals、Equipment Design、Optogenetics

OBJECTIVE: This study aims to develop a flexible, implantable neural probe with tunable stiffness and multifunctionality for electrophysiology, drug delivery, and optogenetics, while minimizing immune response. METHODS: The probe was fabricated from polydimethylsiloxane (PDMS) with a U-turn polyester-filled microchannel (30 μm × 30 μm, 14.7 mm length). Polyester provides rigidity at room temperature and softens near body temperature for tissue compatibility. Mechanical simulations optimized probe dimensions (60 μm × 300 μm × 7 mm), ensuring insertion forces above 1.5 mN. A microfluidic mixer (90 μm × 30 μm, 7 mm) was integrated for controlled drug delivery. Heat transfer and fluid simulations assessed thermal stability and laminar flow. The device also included four gold electrodes, a bio-amplifier, and a blue μ-LED. RESULTS: Experiments confirmed stable channel performance with no leaks or bubbles, effective heat management at 37 °C, and a 60° tip angle as optimal for insertion. The probe consumed ∼46.6 mW and enabled reliable electrophysiological recordings and fluorescence activation in vitro. Biocompatibility testing validated its suitability for long-term implantation. CONCLUSION: The PDMS-polyester probe achieves thermally controlled stiffness, precise drug delivery, and integrated optogenetic stimulation while maintaining stable electrophysiological recording performance. SIGNIFICANCE: This work introduces a multifunctional neural probe that addresses limitations o...