ShrinkCells: Localized and Sequential Shape-Changing Actuation of 3D-Printed Objects via Selective Heating

The unique behaviors of thermoplastic polymers enable shapechanging interfaces made of 3D printed objects that do not require complex electronics integration. While existing techniques rely on external trigger, such as heat, applied globally on a 3D printed object initiating all at once the shape-changing response (e.g., hot water, heat gun, oven), independent control of multiple parts of the object becomes nearly impossible. We introduce ShrinkCells, a set of shape-changing actuators that enables localized heat to shrink or bend, through combining the properties of two materialsconductive PLA is used to generate localized heat which selectively triggers the shrinking of a Shape Memory Polymer. The unique beneft of ShrinkCells is their capability of triggering simultaneous or sequential shape transformations for diferent geometries using a single power supply. This results in 3D printed rigid structures that actuate in sequence, avoiding self-collisions when unfolding. We contribute to the body of literature on 4D fabrication by a systematic investigation of selective heating with two diferent materials, the design and evaluation of the ShrinkCells shape-changing primitives, and applications demonstrating the usage of these actuators.

• Human-centered computing → Human computer interaction (HCI).