Method of fabricating a microfluidic delivery system

• US 6,949,253 B2
• Filed: 08/05/2003
• Issued: 09/27/2005
• Est. Priority Date: 02/28/2001
• Status: Expired due to Term

• Current Assignee: Second Sight Medical Products, Inc.
• Original Assignee: Second Sight Medical Products, Inc.
• Inventors: Greenberg, Robert J., Mech, Brian V.
• Primary Examiner(s): Azpuru, Carlos A.
• Application Number:
  US10/635,633
• Publication Number:
  US 20050045592A1
• Time in Patent Office: 784 Days
• Field of Search: 424/423
• US Class Current: 424/423
• CPC Class Codes: A61K 9/0009 involving or responsive to electricity, magnetism or acoustic waves; Galenical aspects of sonophoresis, iontophoresis, electroporation or electroosmosis microelectromechanical systems A61K9/0097
• CPC Class Codes: A61K 9/0097 Micromachined devices; Microelectromechanical systems [MEMS]; Devices obtained by lithographic treatment of silicon; Devices comprising chips intradermal microneedle arrays A61K9/0021; MEMS in general B81B7/02
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C23C 16/274 using microwave discharges
• CPC Class Codes: C23C 16/277 using other elements in the gas phase besides carbon and hydrogen; using other elements besides carbon, hydrogen and oxygen in case of use of combustion torches; using other elements besides carbon, hydrogen and inert gas in case of use of plasma jets
• CPC Class Codes: C23C 16/278 doping or introduction of a secondary phase in the diamond
• CPC Class Codes: C23C 16/279 control of diamond crystallography

Abstract

An implantable biocompatible microchip drug delivery substrate is coated with a thin film of ultra-nanocrystalline diamond; assuring that the device is biocompatible and impermeably sealed, to prevent the substrate from being dissolved by the living tissue and to protect the drugs from premature release or undesired reaction with the body fluids. The coating is selectively patterned by doping to create electrically conductive areas that can be used as an electrically activated release mechanism for drug delivery. The conformal ultra-nanocrystalline diamond coating uniformly covers the device, providing relief from sharp edges and producing a strong, uniformly thick impermeable coating around sharp edges and on high aspect-ratio parts. The ultra-nanocrystalline diamond coating provides a conformal coating on the biocompatible device, which is of approximately uniform thickness around sharp corners and on high aspect-ratio parts. The conformal nature of the coating assures impermeability and strength despite the presence of difficult to coat shapes.

Claims

1. A method of fabricating a microfluidic delivery system for release of molecules having reservoirs containing the molecules for release comprising:

providing a substrate;

depositing an ultra-nanocrystalline diamond coating on the substrate for use as an impermeable and biocompatible protective coating;

filling the reservoirs with molecules to be release into living tissue; and

capping the reservoirs with a cap material which retains the molecules.

2. The method of claim 1 wherein said substrate is comprised of silicon.

3. The method of claim 1 wherein said cap material is selectively permeable to the molecules.

4. The method of claim 1 wherein said cap material disintegrates to release the molecules.

5. The method of claim 1 wherein said cap material is comprised of ultra-nanocrystalline diamond.