3D Printing and Shape Memory Alloys

This paper presents a novel method combining the use of 3D printing (3DP) and shape memory alloys (SMAs) to compose kinetic architectural elements that are energy- and material-efficient within compact-integrated composites. Kinetic systems for architectural use have been explored since the late twentieth century using motor mechanics. However, the primary challenges of this method include maintenance of mechanical units, their high energy demand, and noise during actuation. To address these shortcomings, this research explores a hybrid of 3DP motion-optimized parts with embedded SMAs as a muscle that changes shape with temperature stimulus. This combination leverages 3DP to geometrically control shape-morphing behavior for material-efficient, compact-integrated parts, and SMA to allow for low maintenance and soundless actuation. However, current SMA applications permanently require energy to stabilize one geometric state. To reduce required energy to a minimum, we present a novel method that combines embedded SMA with 3DP bi-stable mechanism. This approach only requires energy for switching between states, dramatically reducing energy consumption. This could be the key to efficient architectural applications. As part of the evaluation, factors such as controllability of shape morphing behavior, repeatability, materials, and energy efficiency are investigated. An experimental program is developed with different SMA-embedded, 3D-printed specimens. The program then explores a possible approach to scaling up with two prototypes. The presented synthesis of smart materials with additive manufacturing of bi-stable geometries could contribute to the field of composites in kinetic architecture by reducing the operational energy, thus opening a path towards more sustainable real-world applications.