Patent ID: 8641464

Claim:
A method of changing a lateral shape of a deformable fin having first and second laterally opposite side elements connected to a base by respective first and second hinges, the method comprising: causing a first distal end of a first spreader having a first proximal end coupled to the base to impose a first force on the fin in response to relative movement between the first spreader and the fin caused by a first longitudinal deflection of the fin relative to the base in a first deflection direction; and using the first force from the first spreader to spread the first and second laterally opposite side elements apart; wherein spreading the first and second laterally opposite side elements apart comprises rotating the first and second laterally opposite side elements about respective hinge axes of the first and second hinges, wherein each of the respective hinge axes extends away from a central longitudinal axis of the fin and away from the base at a respective acute angle from the central longitudinal axis of the fin, to impart a concave shape to the fin, opposite the first deflection direction, in response to the rotating the first and second laterally opposite side elements about the respective hinge axes of the first and second hinges caused by the first longitudinal deflection of the fin.