Method for sputtering tini shape-memory alloys
AssigneesTiNi Alloy Company, Smart Therapeutics, Inc.
InventorsA. David Johnson, Valery V. Martynov, Vikas Gupta, Arani Bose
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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.
Claims11
A method of forming a thin-fim device, comprising
- placing in a magnetron sputtering device, a mandrel having an exposed, etchable outer layer that corresponds to an open, interior volume of the thin-film device to be formed,
- providing the magnetron sputtering device with a TiNi alloy target composed of between 45-55% each of titanium and nickel,
- sputter depositing material from the TiNi alloy target to the mandrel under low-pressure, low-oxygen condition, the TiNi alloy target being adjacent to the mandrel,
- during said sputter depositing, moving the mandrel relative to the TiNi alloy target, to achieve substantially uniform sputter deposition over the exposed outer layer of the mandrel,
- continuing said sputtering until a desired thin-film alloy thickness between 0.5 and 100 microns is formed on the mandrel,
- heating the thin-film on the mandrel under annealing conditions, and
- releasing the thin-film device so formed from the mandrel.
Dependencies are inferred from the claim text.