Shape-changing interfaces use physical changes of shape as input or output to convey information, and interact with users. Plants are natural shape-changing interfaces, expert in adjusting their shape or modality to adapt to the environment. In this paper, plant-derived natural shape-changing phenomena are systematically analyzed. Then, several corresponding plant-inspired design strategies for shape-changing interfaces are summarized with recent advancements including material selections and syntheses, fabrication methods, and actuating mechanisms. Practical applications across diverse domains aim to prove the advantages and potential of plant-inspired shape-changing interfaces in agriculture, healthcare, architecture, robotics, etc. Furthermore, the opportunities and challenges are also discussed, such as design thinking in interdisciplinary tasks, dynamic behavior and control principles, novel materials and processes, application scenario and functionality matching, and large-scale application requirements. This paper is expected to inspire in-depth research on plant-inspired shape-changing interfaces.

Touch fastening structures are widely used to quickly assemble and disassemble an object with multiple parts. However, such structures are under-explored in the context of additive manufacturing for personal fabrication. We proposed Touch-n-Go, a method for designing touch-fastening structures with customizable mechanical properties such as holding capacities or shearing strength. Additionally, the customization of fastener patterns enables both static and dynamic connections, and the dynamic connections grant the freedom of rotation and translation. To facilitate the customization process, we developed a design tool that allows the integration of fastening structures on the surface of a 3D-printed object. Furthermore, we validated the fastening properties of Touch-n-Go through a series of experiments, and the result exhibits performances that match or even surpass off-the-shelf fasteners. Finally, we demonstrated the implementation of Touch-n-Go through a collection of applications.

Snap-through instability, like the rapid closure of the Venus flytrap, is gaining attention in robotics and HCI. It offers rapid shape reconfiguration, self-sensing, actuation, and enhanced haptic feedback. However, conventional snap-through structures face limitations in fabrication efficiency, scale, and tunability. We introduce SnapInflatables, enabling safe, multi-scale interaction with adjustable sensitivity and force reactions, utilizing the snap-through instability of inflatables. We designed six types of heat-sealing structures enabling versatile snap-through passive motion of inflatables with diverse reaction and trigger directions. A block structure enables ultra-sensitive states for rapid energy release and force amplification. The motion range is facilitated by geometry parameters, while force feedback properties are tunable through internal pressure settings. Based on experiments, we developed a design tool for creating desired inflatable snap-through shapes and motions, offering previews and inflation simulations. Example applications, including a self-locking medical stretcher, interactive animals, a bounce button, and a large-scale light demonstrate enhanced passive interaction with inflatables.

In this paper, we present X-Hair, a method that enables 3D-printed hair with various forms, properties, and functions. We developed a two-step suspend printing strategy to fabricate hair-like structures in different forms (e.g. fluff, bristle, barb) by adjusting parameters including Extrusion Length Ratio and Total Length. Moreover, a design tool is also established for users to customize hair-like structures with various properties (e.g. pointy, stiff, soft) on imported 3D models, which virtually shows the results for previewing and generates G-code files for 3D printing. We demonstrate the design space of X-Hair and evaluate the properties of them with different parameters. Through a series of applications with hair-like structures, we validate X-hair’s practical usage of biomimicry, decoration, heat preservation, adhesion, and haptic interaction.

The field of Human-Computer-Interaction (HCI) has been consistently utilizing kinematic mechanisms to create tangible dynamic interfaces and objects. However, the design and fabrication of these mechanisms are challenging due to complex spatial structures, step-by-step assembly processes, and unstable joint connections resulting from the inevitable matching errors within separated parts. In this paper, we propose an integrated fabrication method for one-step FDM 3D printing (FDM3DP) kinematic mechanisms to create dynamic objects without additional post-processing. We describe the Arch-printing and Support-bridges method, which we call All-in-One Print, that compiles given arbitrary solid 3D models into printable kinematic models as G-Code for FDM3DP. To expand the design space, we investigate a series of motion structures (e.g., rotate, slide, and screw) with multi-stabilities and develop a design tool to help users quickly design such dynamic objects. We also demonstrate various application cases, including physical interfaces, toys with interactive aesthetics and daily items with internalized functions.

4D printing encodes transformability over time, which empowers users to create artifacts by on-demand deformation. The creative process of 4D printing shape-changing artifacts can be challenging because of its discontinuous fabrication steps, such as digital designing, specific path planning, automatic printing and manual triggering. We hypothesize that switching from typical 4D printing reliant on 3D printers to a more “handcrafted” method can allow users to understand and continuously reflect upon the artifact and its transformability. Towards this vision, we introduce 4Doodle, a hybrid craft approach that integrates unique deformation controllability and five techniques for freehand 4D printing, using a 3D pen. To tackle the shape-changing challenges of uncertain hands-on fabrication, we develop a mixed reality system to help novices master the manual skills of 4D printing. We also demonstrate a series of 4D printed artifacts with fully human intervention. Finally, our user study shows that 4Doodle lowers the skill-acquisition barrier associated with handcrafting 4D printed artifacts, and it has great potential for creative production and spatial ability.

Bridges are unique structures appeared in fused deposition modeling (FDM) that make rigid prints flexible but not fully explored. This paper presents X-Bridges, an end-to-end workflow that allows novice users to design tunable bridges that can enrich 3D printed objects' deformable and physical properties. Specifically, we firstly provide a series of deformation primitives (e.g. bend, twist, coil, compress and stretch) with three versions of stiffness (loose, elastic, stable) based on parametrized bridging experiments. Embedding the printing parameters, a design tool is developed to modify the imported 3D model, evaluate optimized printing parameters for bridges, preview shape-changing process, and generate the G-code file for 3D printing. Finally, we demonstrate the design space of X-Bridges through a set of applications that enable foldable, resilient, and interactive shape-changing objects.