A method of forming a single crystal in a thin film by progressively
rapidly heating (and cooling) a narrow band of amorphous material. The
amorphous thin film may be of shape memory alloy such as TiNi or CuAlNi.
Heating may be accomplished by a line-focused laser beam. The thin film
may be formed by sputter deposition on a substrate such as silicon. The
thin film crystal that is formed has non-isotropic stress/strain
characteristics, and very large recoverable strain in a preferred
direction. The single crystal SMA exhibits greater strain recovery;
Constant force deflection; Wider transition temperature range; Very
narrow loading hysteresis; and Recovery that is repeatable & complete.
Single Crystal SMA is manufactured by pulling a single crystal from melt,
a method similar to that used by the semiconductor industry to fabricate
silicon boules. This process enables manufacture of materials that
approach theoretical limits.