Ultra-low fractional area coverage flow diverter for treating aneurysms and vascular diseases

Abstract

The various embodiments described herein include methods for fabricating thin- film flow diversion apparatuses. In one aspect, a method includes: (1) creating a plurality of trenches using photolithography and deep reactive ion etching on a substrate; (2) depositing a metal sacrificial layer on the substrate; (3) forming a Nitinol layer with a plurality of fenestrations by depositing Nitinol on the metal sacrificial layer; (4) forming a thin-film of Nitinol by removing the metal sacrificial layer; (5) crystallizing the thin-film of Nitinol; and (6) elongating the thin-film of Nitinol.

What is claimed is: 
     
         1 . A method for fabricating a thin-film flow diversion apparatus, comprising:
 creating a plurality of trenches using photolithography and deep reactive ion etching on a substrate;   depositing a metal sacrificial layer on the substrate;   forming a Nitinol layer with a plurality of fenestrations by depositing Nitinol on the metal sacrificial layer;   forming a thin-film of Nitinol by removing the metal sacrificial layer;   crystallizing the thin-film of Nitinol; and   elongating the thin-film of Nitinol.   
     
     
         2 . The method of  claim 1 , wherein the substrate comprises a silicon substrate. 
     
     
         3 . The method of  claim 1 , wherein depositing the metal sacrificial layer comprises depositing a copper sacrificial layer via e-beam evaporation. 
     
     
         4 . The method of  claim 1 , further comprising depositing a silicon dioxide barrier layer by plasma-enhanced chemical vapor deposition on the metal sacrificial layer prior to the depositing of the Nitinol. 
     
     
         5 . The method of  claim 1 , wherein the depositing of the Nitinol comprises depositing the Nitinol by a direct current sputtering process. 
     
     
         6 . The method of  claim 1 , further comprising generating a super-hydrophilic surface on the thin-film of Nitinol utilizing hydrogen peroxide. 
     
     
         7 . The method of  claim 6 , wherein the super-hydrophilic surface has a water contact angle of less than 5 degrees. 
     
     
         8 . The method of  claim 6 , wherein the super-hydrophilic surface is configured to deter platelet adhesion at a rate of less than 3 parts per millimeter squared when subjected to platelet rich plasma for 3 or more hours. 
     
     
         9 . The method of  claim 1 , wherein the Nitinol is deposited via direct current sputtering. 
     
     
         10 . The method of  claim 1 , wherein the Nitinol is deposited via hot-target sputter deposition. 
     
     
         11 . The method of  claim 1 , wherein crystallizing the thin-film of Nitinol comprises heating the thin-film within a vacuum. 
     
     
         12 . The method of  claim 1 , wherein each fenestration of the plurality of fenestrations has a pore size of less than 500 microns. 
     
     
         13 . The method of  claim 1 , wherein each fenestration of the plurality of fenestrations has a pore size between 200 microns and 400 microns. 
     
     
         14 . The method of  claim 1 , wherein the thin-film flow diversion apparatus comprises a thin-film stent cover having a surface coverage of less than 30%. 
     
     
         15 . The method of  claim 1 , wherein the fenestrations comprise diamond-shaped apertures. 
     
     
         16 . The method of  claim 1 , wherein the thin-film has a thickness of less than 12 microns.