A rotor of a rotary machine includes a ring-like fixing member press-fit and fixed to a shaft so as to limit a position of a rotor core in a shaft axial direction and an end plate fixed to an outer peripheral side of the fixing member so as to limit a position of a magnet, embedded in the rotor core, in the shaft axial direction. Influences of a difference in thermal expansion between the shaft and the end plate are lessened by the fixing member. A material is selected so that a value of a coefficient of linear expansion of the fixing member becomes equal to an intermediate value between a coefficient of linear expansion of the shaft made of iron and a coefficient of linear expansion of the end plate made of a non-magnetic body.

Various shape memory polymer (SMP) devices are disclosed. Many of these SMP devices can be used as attachment and/or release mechanisms for any number of different applications. These SMP devices can use various characteristics of the SMP material to allow for various shape changes. These shape changes, in some embodiments, can be used to provide for release and/or attachment devices, for example, SMP bolts, SMP screws, SMP collars, SMP pillars, SMP panels, and/or SMP rivets, to name a few. An SMP device can include a first geometric state and a second geometric shape. The first geometric shape can restrict motion of two distinct objects relative to one another and the second geometrical shape can allow motion of two distinct objects relative to one another.