A transport device (100) comprises a housing (110), an actuator (130) and a drive (150). The housing has a fluid inlet (111, 113) and a fluid outlet (113, 111). The actuator (130) comprises a magnetic shape-memory alloy, and the actuator (130) is arranged at least in sections in the housing (110). The actuator (130) can be deformed by the drive (150) in such a way that at least one cavity (135, 135) for the fluid is formed in the actuator (130), which cavity can be moved by the drive (150) in order to transport the fluid in the cavity (135, 135) from the fluid inlet (111, 113) to the fluid outlet (113, 111). At least one section of the actuator (130) has a separation layer (1380) by which a direct contact between the fluid and the actuator (130) is prevented in said section of the actuator (130).

A rigidity variable apparatus includes: one or a plurality of coil units including a spiral-shaped coil portion in which a plurality of SMA element wires made of a shape-memory alloy are wound around an axis at a first pitch in a state where the SMA element wires are overlapped with each other in a predetermined axis direction, each of the SMA element wires memorizing a spiral shape with a pitch narrower than the first pitch, one of the plurality of SMA element wires starting to deform to the memorized spiral shape with a predetermined pitch when at a predetermined temperature or higher, another of the plurality of SMA element wires starting to deform to the spiral shape with a different pitch; and an electrothermal heater configured to heat the coil portion.

Articles and methods in which an electric field is used to actuate a material are generally described. Provided in one embodiment is a method including applying an electric field to a ceramic material. Applying the electric field to the ceramic material can transform the ceramic material from a first solid phase to a second distinct solid phase. The applied electric field is less than a breakdown electric field of the ceramic material, according to certain embodiments.

A metal plate contains a shape memory alloy (e.g., a nitinol alloy) capable of exhibiting the one-way memory effect.