Biocompatible electrode component and method for fabrication thereof

Abstract

The present invention provides methods for fabricating an electrode device component, the method comprising the steps of: (i) providing a biocompatible carrier material, and (ii) performing an ablative method on the biocompatible carrier material to form a recess, the recess capable of receiving a biocompatible electrode material. The components so fabricated are useful as carriers for biological electrodes, such as cochlear electrodes and nerve cuff electrodes.

Description

technical field

[0001] The present invention generally relates to electrodes and methods for their manufacture. In particular, the invention relates to electrodes that can be used to provide electrical stimulation or sense electrical activity in biological tissue. Background technique

[0002] Electrical signals are important mediators in many biological systems, and this is especially true in the nervous system of animals. For example, skeletal muscle contraction is prompted by depolarization of cells of central nervous system origin that propagates to the peripheral neural membrane, which communicates electrically with the muscle.

[0003] Important sensory functions depend on the relay of electrical currents from the peripheral nerves to the central nervous system. For example, stimulation of photoreceptor cells in the eye activates neurons of the optic nerve, which in turn activates cells of the visual cortex in the brain. Similarly, sound waves mechanically stimulate...

Examples

example 1

[0131] Example 1: Fabrication of Electrode Parts Using Silicone as a Support and Platinum as Conductive Material

[0132] Silicone elastomer MED4860 was mixed and diluted in 40% by weight heptane ( figure 1 a).

[0133] A piece of substrate was placed on the chuck of the spin coater and the surface of the substrate was covered with silicone using a pipette.

[0134] Adjust the spin coating rate and duration to the viscosity of the silicone to obtain the desired thickness of about 15-20 microns. For MED4860 silicone diluted with 40% heptane, the following conditions were used: 2000 rpm for 20 seconds to obtain a 15 micron thick layer. Immediately after spin coating, the sample was placed on an electric furnace set at 100° C. and left to evaporate the solvent for 20 minutes, which was sufficient to obtain a cured silicone film. Spin coating can be repeated several times to build thicker films when needed.

[0135] When the desired film thickness is reached, the silicone fi...

example 2

[0145] Example 2: First Alternative Fabrication of Electrode Components Using Silicone as Support and Platinum as Conductive Material Substitution Method ("Design A")

[0146] The electrode components in this example were prepared in a manner similar to that disclosed in Example 1, except that the silicone support was solvent cast from a silicone solution. The mold was made of Teflon into which the silicone solution was poured. Solutions were prepared at lower viscosities than those typically used for spin coating.

[0147] After casting, any solvent is evaporated and the silicone is allowed to cure. Curing was accelerated by heating to 90° C., under which conditions curing was achieved in 30 minutes. After solidification and cooling, the sheets are peeled from the mold.

[0148] More variance in the electrode parts produced in this example is the use of a silicone protective layer instead of Kapton TM tape, and a silicone mask was used instead of the brass foil disclo...

example 3

[0154] Example 3: Second Alternative Fabrication of Electrode Components Using Silicone as a Support and Platinum as Conductive Material Alternative approach ("Design B").

[0155]In addition to the methods described in Examples 1 and 2, silicone substrates can be modified by laser machining of silicone to produce higher surface areas. In this example, the fused silica content in the silicone was increased. Alternatively, any other organic or inorganic (non-metallic) nanoparticles or microparticles can be used as fillers. The formulation and fraction of the filler is adjusted such that the silicone retains the desired elasticity. The particles are evenly distributed within the matrix, and these particles are not ablated by the laser when laser processing silicone. Thus, vaults are formed in the silicone carrier. Since the particles are not tightly embedded within the silicone matrix, they are washed away so that only the silicone remains on the surface. These domes inc...

technical field

[0001] The present invention generally relates to electrodes and methods for their manufacture. In particular, the invention relates to electrodes that can be used to provide electrical stimulation or sense electrical activity in biological tissue. Background technique

[0002] Electrical signals are important mediators in many biological systems, and this is especially true in the nervous system of animals. For example, skeletal muscle contraction is prompted by depolarization of cells of central nervous system origin that propagates to the peripheral neural membrane, which communicates electrically with the muscle.

[0003] Important sensory functions depend on the relay of electrical currents from the peripheral nerves to the central nervous system. For example, stimulation of photoreceptor cells in the eye activates neurons of the optic nerve, which in turn activates cells of the visual cortex in the brain. Similarly, sound waves mechanically stimulate...

Examples

example 1

[0131] Example 1: Fabrication of Electrode Parts Using Silicone as a Support and Platinum as Conductive Material

[0132] Silicone elastomer MED4860 was mixed and diluted in 40% by weight heptane ( figure 1 a).

[0133] A piece of substrate was placed on the chuck of the spin coater and the surface of the substrate was covered with silicone using a pipette.

[0134] Adjust the spin coating rate and duration to the viscosity of the silicone to obtain the desired thickness of about 15-20 microns. For MED4860 silicone diluted with 40% heptane, the following conditions were used: 2000 rpm for 20 seconds to obtain a 15 micron thick layer. Immediately after spin coating, the sample was placed on an electric furnace set at 100° C. and left to evaporate the solvent for 20 minutes, which was sufficient to obtain a cured silicone film. Spin coating can be repeated several times to build thicker films when needed.

[0135] When the desired film thickness is reached, the silicone fi...

example 2

[0145] Example 2: First Alternative Fabrication of Electrode Components Using Silicone as Support and Platinum as Conductive Material Substitution Method ("Design A")

[0146] The electrode components in this example were prepared in a manner similar to that disclosed in Example 1, except that the silicone support was solvent cast from a silicone solution. The mold was made of Teflon into which the silicone solution was poured. Solutions were prepared at lower viscosities than those typically used for spin coating.

[0147] After casting, any solvent is evaporated and the silicone is allowed to cure. Curing was accelerated by heating to 90° C., under which conditions curing was achieved in 30 minutes. After solidification and cooling, the sheets are peeled from the mold.

[0148] More variance in the electrode parts produced in this example is the use of a silicone protective layer instead of Kapton TM tape, and a silicone mask was used instead of the brass foil disclo...

example 3

[0154] Example 3: Second Alternative Fabrication of Electrode Components Using Silicone as a Support and Platinum as Conductive Material Alternative approach ("Design B").

[0155]In addition to the methods described in Examples 1 and 2, silicone substrates can be modified by laser machining of silicone to produce higher surface areas. In this example, the fused silica content in the silicone was increased. Alternatively, any other organic or inorganic (non-metallic) nanoparticles or microparticles can be used as fillers. The formulation and fraction of the filler is adjusted such that the silicone retains the desired elasticity. The particles are evenly distributed within the matrix, and these particles are not ablated by the laser when laser processing silicone. Thus, vaults are formed in the silicone carrier. Since the particles are not tightly embedded within the silicone matrix, they are washed away so that only the silicone remains on the surface. These domes inc...

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