Thin-film shape memory alloy device and method
AssigneesStryker Corporation, Stryker NV Operations Limited
InventorsA. David Johnson, Valery V. Martynov, Vikas Gupta, Arani Bose
Life of this patent
Estimating the term…
Abstract
A thin film device, such as an intravascular stent, is disclosed. The device is formed of a seamless expanse of thin-film (i) formed of a sputtered nitinol shape memory alloy, defining, in an austenitic state, an open, interior volume, having a thickness between 0 5-50 microns, having an austenite finish temperature Af below 37° C.; and demonstrating a stress/strain recovery greater than 3% at 37° C. The expanse can be deformed into a substantially compacted configuration in a martensitic state, and assumes, in its austenitic state, a shape defining such open, interior volume. Also disclosed is a sputtering method for forming the device.
Claims20
A method of forming a thin-film device, comprising:
- placing a mandrel in a magnetron sputtering device, the mandrel having an etchable outer surface layer;
- disposing a plurality of structural members on the outer mandrel surface layer;
- sputter depositing material from an TiNi alloy target to the mandrel while moving the mandrel relative to the TiNi alloy target to thereby achieve substantially uniform sputter deposition of the TiNi alloy over the outer surface layer of the mandrel, until a layer of TiNi alloy having a desired thickness is deposited on the outer surface layer of the mandrel, with the structural members being embedded in the deposited layer of TiNi alloy;
- and
- heating to thereby anneal the deposited layer of TiNi alloy on the mandrel.
A method of forming a thin-film device, comprising:
- forming an etchable outer surface layer on a mandrel;
- disposing a plurality of structural members on the mandrel outer surface layer;
- sputter depositing material from an TiNi alloy target to the mandrel while moving the mandrel relative to the TiNi alloy target to thereby achieve substantially uniform sputter deposition of the TiNi alloy over the outer surface layer, until a layer of TiNi alloy having a desired thickness is deposited on the outer surface layer, with the structural members being embedded in the deposited layer of TiNi alloy;
- and
- heating to thereby anneal the deposited layer of TiNi alloy on the mandrel.
A method of forming a fenestrated thin-film device, comprising:
- placing a mandrel in a magnetron sputtering device, the mandrel having a polyimide layer and an etchable sacrificial outer surface layer disposed on the polyimide layer;
- sputter depositing material from TiNi alloy target onto the sacrificial outer surface layer of the mandrel while moving the mandrel relative to the TiNi alloy target to thereby achieve substantially uniform sputter deposition of the TiNi alloy over the outer surface layer of the mandrel until a layer of TiNi alloy having a desired thickness is deposited on the outer surface layer of the mandrel;
- heating to thereby anneal the deposited layer of TiNi alloy on the mandrel;
- forming on the annealed layer of TiNi alloy, a resist layer containing a pattern of openings;
- and
- exposing the layer of TiNi alloy and the resist layer to an etchant under conditions effective to create fenestrations in the layer of TiNi alloy corresponding to the pattern of openings.
Dependencies are inferred from the claim text.