Implantable device using ultra-nanocrystalline diamond
View Patent ↗An implantable biocompatible device, that may be either a sensor or stimulator, having electronic circuitry and electrodes formed on a substrate, is uniformly covered with a coating approximately one-micron thick of ultra-nanocrystalline diamond, hermetically sealing the electronic circuitry. Selected electrodes are either left uncovered during coating or uncovered by conventional patterning techniques, allowing the electrodes to be exposed to living tissue and fluids. The ultra-nanocrystalline diamond coating may be doped to create electrically conductive electrodes. These approaches eliminate the need for a hermetically sealed lid or cover to protect hybrid electronic circuitry, and thus allow the device to be thinner than otherwise possible. The conformal ultra-nanocrystalline diamond coating uniformly covers the device, providing relief from sharp edges and producing a strong, uniformly thick hermetic coating around sharp edges and on high aspect-ratio parts.
1. A biocompatible device which communicates electrical signals with tissue in a living body, comprising:
an integrated circuit, said integrated circuit comprising a semiconductor substrate having at least one surface on which electronic circuitry is formed;
electrodes for contacting the living tissue which are formed on said at least one surface of said semiconductor substrate;
means for electrically connecting said stimulator electrodes with said electronic circuitry formed on said at least one surface of said semiconductor substrate;
an ultra-nanocrystalline diamond coating that covers all areas of said at least one surface of said semiconductor substrate, except for selected portions of said stimulator electrodes; and
means for making electrical connection with and providing operating power to said electronic circuitry formed on said at least one surface of said semiconductor substrate.
2. The biocompatible device according to claim 1 wherein said integrated circuit comprises a sensor.
3. The biocompatible device according to claim 1 wherein said integrated circuit comprises a stimulator.
4. The biocompatible device according to claim 1 wherein said ultra-nanocrystalline diamond coating is approximately constant in thickness over uneven portions of said device to provide a smooth coating with rounded edges.
5. The biocompatible device according to claim 1 wherein said ultra-nanocrystalline diamond coating is patterned by photolithography.
6. The biocompatible device according to claim 1 wherein said ultra-nanocrystalline diamond coating is patterned by selective seeding.
7. The biocompatible device according to claim 1 wherein said ultra-nanocrystalline diamond coating is patterned by oxygen etching.
8. A biocompatible device which communicates electrical signals with tissue in a living body, comprising:
an integrated circuit, said integrated circuit comprising a semiconductor substrate having at least one surface on which electronic circuitry is formed;
electrodes for contacting the living tissue which are formed on said at least one surface of said semiconductor substrate;
means for electrically connecting said stimulator electrodes with said electronic circuitry formed on said at least one surface of said semiconductor substrate;
a diamond coating that covers all areas of said at least one surface of said semiconductor substrate, except for selected portions of said stimulator electrodes; and
means for making electrical connection with and providing operating power to said electronic circuitry formed on said at least one surface of said semiconductor substrate.