This invention introduces soft, stretchable hydrogel microelectrodes reinforced with aligned carbon nanotubes (CNTs) to achieve tunable anisotropic conductivity and compliant mechanics. The system maintains low-impedance electrical performance during deformation while enabling integrated optical and microfluidic functionality for next-generation biointerfaces in chronic neural and muscular applications.
Background: Long-term biointerfaces face major limitations due to the mechanical mismatch between soft biological tissues and rigid or isotropic electrodes. Conventional flexible materials often exhibit poor conductivity under strain, fatigue failure, and instability in physiological environments. Furthermore, most systems are unable to support multifunctional operations such as simultaneous electrical recording, optical stimulation, and localized drug delivery—capabilities essential for chronic studies of dynamic tissues. A multifunctional, durable, and mechanically adaptive interface is needed to address these limitations.
Technology Overview: This technology features soft and stretchable microelectrodes fabricated from a semi-crystalline polyvinyl alcohol (PVA) hydrogel reinforced with carbon nanotubes (CNTs). Using a Tension Reinforced Anisotropic Nano-orientation (TRAN) process—combining controlled crosslinking, stretching, and annealing—the CNTs and PVA nanocrystals are aligned to produce tunable anisotropic conductivity and mechanical response. The electrodes preserve stable impedance around 1 kHz during repeated deformation and remain functional under strains up to 56.6%. Monolithically integrated microfluidic channels and hydrogel optical waveguides allow combined drug delivery and optogenetic stimulation in a compliant and biocompatible platform suitable for chronic implantation.
Advantages: • Tunable anisotropic conductivity aligned to tissue direction for high-fidelity signal capture • High fatigue resistance maintaining stable impedance during repetitive deformation • Soft hydrogel mechanics minimize tissue damage and inflammatory response • Stable electrical performance near 1 kHz for reliable chronic recordings • Stretchability up to 56.6% for dynamic organs and muscles • Integrated microfluidics and optics for multifunctional interfacing • Physiological water content and biocompatibility for long-term use • Scalable processing combining crosslinking, stretching, and annealing
Applications: • Chronic neural recording and stimulation in freely moving animal models • Clinical neuromuscular diagnostics and long-term monitoring • Targeted neuromodulation with combined electrical, optical, and drug delivery • Conformal cardiac electrophysiology mapping for arrhythmia management • Spinal cord and peripheral nerve interfaces for rehabilitation research • Implantable myoelectric sensing for advanced prosthetic control
Intellectual Property Summary: • United States – 67/772,623 – Provisional – Filed 04/23/2025 – Status: Filed
Stage of Development: In-vivo experiments with mice.
Licensing Status: This technology is available for licensing.
Licensing Potential: Strong potential for partners in neural engineering, biomedical device development, and implantable biosystems seeking durable, multifunctional, and biocompatible electrode technologies for chronic and dynamic interfacing applications.
Additional Information: Experimental impedance data, anisotropic conductivity profiles, and in-vivo performance results available upon request.
Inventors: Siyuan Rao, Sizhe Huang, Qianbin Wang, Ruobai Xiao