Implantable clip-on micro-cuff electrode for functional stimulation and bio-potential recording

A method for fabricating a nerve cuff, comprising:

• depositing a commercially available mold release chemical onto a substrate via spin coating to form a mold release layer;
• depositing a first layer of silicone onto the mold release layer via spin coating and thermally curing the silicone layer;
• coating a metal wire with a mold release chemical and allowing the chemical to solidify;
• placing the coated metal wire in conformal contact with the thin layer of silicone;
• depositing a second layer of uncured silicone over the wire-foil assembly and thermally curing the layer, wherein the second silicon layer is thicker than the first silicone layer;
• dissolving the mold release layer on the substrate to release the silicone structure from the substrate;
• dissolving the mold release coating on the metal wire to yield a hollow cylindrical cuff in the silicone structure;
• forming the desired shape and dimensions of the nerve cuff features including the pinch hinge on the silicone structure;
• cutting a longitudinal slit on the cylindrical cuff opposite the pinch hinge in the silicone structure;
• inserting electrode wires into the cuff via a syringe needle, such that un-insulated parts of the wires serve the function of electrode leads inside the cuff, and the segments of the wires outside the cuff are insulated;
• holding the electrode wires in place by the cuff's silicone material after withdrawal of the needle;
• and
• reinforcing the point of exit of the electrode wires from the main body of the cuff device.

A method for fabricating a nerve cuff, comprising:

• making a master mold of plastic or metal consisting of two parts;
• machining the first part of the master mold to define a half cylinder wherein a pin with a suitable cross-section is placed at the bottom of the half cylinder;
• machining the first part to define a groove perpendicular to the half cylinder;
• machining the second part of the master mold to define a half cylinder wherein two grooves are made to form the two arms of the pinch hinge;
• coating both parts of the master mold by a mold release chemical layer and allowing the chemical to solidify;
• placing at least one metal foil electrode in contact with approximately half the circumference of the cylindrical pin in the first part of the mold;
• placing the second part of the master mold over the first part and securing them together via suitable clamps;
• placing the master mold assembly vertically on a base and pouring silicone pre-polymer into the cavity of the mold assembly;
• thermally curing the silicone inside the cavity of the master mold;
• separating the two parts of the master mold and dissolving the mold release coating in an appropriate solvent;
• releasing the cured silicone structure.

A nerve cuff, comprising:

• a member including an aperture having a longitudinal slit;
• a pinch hinge having a first arm and a second arm, the first arm spaced apart from the second arm, the first and second arms attached to the member;
• at least one electrode positioned in the member;
• wherein the longitudinal slit is configured to open when a compressive force is applied to an outer surface of the first arm and an outer surface of the second arm, whereby the first arm and second arm are squeezed together.