Advanced Architectures and Operating Principles for Electrochemical Neuro-Modulation

Technology

The prosthetic device uses ion-selective membranes (ISMs) to enable electrically controlled, local modulation of ion concentrations near targeted neural tissue. The device employs closed-loop feedback systems, including a configuration in which a single ISM both senses ion concentration via potentiometric measurement and modulates concentration via applied current, and a configuration that uses co-localized ISMs for separate sensing and modulation functions. In operation, the device begins by positioning neural tissue in proximity to an ISM interface such that an applied electric field drives selective ion transport through the membrane, producing ion concentration polarization. When an electric current is applied across the ISM, target ions are selectively transported, resulting in localized enrichment or depletion of those ions near the nerve. In another embodiment, the device maintains the concentration of a target ion using membrane transfer selectivity that effectively encodes a prescribed ion concentration in the device architecture.

Problem Addressed

Precise, localized control of neural activity remains a fundamental challenge in neuromodulation, particularly the ability to selectively modulate targeted neural populations without affecting surrounding tissue. Existing approaches, including conventional electrical stimulation and localized chemical neuromodulation, lack the specificity and controllability required for reliable therapeutic modulation. Electrical stimulation often activates large volumes of neural tissue, while prior chemical neuromodulation strategies typically rely on bulky micro electromechanical system-based reservoirs with finite ion supply and limited dynamic control. This technology addresses these challenges by enabling reservoir-free, localized electrochemical modulation of ion concentrations at the nerve interface, enabling both nerve blocking and facilitation with high spatial precision. By converting electrical input into controlled ionic transport, the system operates within electrode charge injection limits while supporting long-term and reversible implantable neuromodulation.

Advantages

• Closed-loop operation enabling real-time sensing and feedback to maintain ion concentrations at the nerve interface
• Highly localized neuromodulation enabling precise control of neural activity with reduced off-target effects
• Ability to both inhibit and facilitate neural activity through selective ion concentration control
• Lower current densities at the tissue interface and reservoir-free operation, facilitating extended electrode lifetime and compact implantable device designs
• Use of ISMs with established biocompatibility, enabling integration with existing neural interface technologies for long-term implantable use.

Publications

Flavin, Matthew T. Electrochemical Modulation of Peripheral Nerves Using Ion-Selective Membranes. PhD diss., Massachusetts Institute of Technology, 2021. Accessed January 22, 2026. https://dspace.mit.edu/handle/1721.1/139226

Flavin, Matthew T., Marek A. Paul, Alexander S. Lim, Charles A. Lissandrello, Robert Ajemian, Samuel J. Lin, and Jongyoon Han. “Electrochemical Modulation Enhances the Selectivity of Peripheral Neurostimulation In Vivo.” Proceedings of the National Academy of Sciences 119, no. 23 (June 7, 2022): e2117764119. https://doi.org/10.1073/pnas.2117764119