MagFace: Interference-Resistant Facial Gesture Recognition System on Cycling Glasses with Low-Power Magnetic SensingFacial interaction provides a safe, hands-free input method for cyclists. However, existing wearable facial gesture recognition suffers from severe interference in real-world conditions such as lighting, vibration, sweat, noise, and temperature changes. We present MagFace, an interference-resistant recognition system for cycling glasses using energy-efficient magnetic sensing. MagFace employs four pairs of magnetic silicone and magnetometers on the frame to capture subtle facial skin movements, operating at 30 Hz with a peak power of 150 mW. A tailored deep learning pipeline effectively learns magnetic signals for gesture classification. An evaluation (N=15) shows that MagFace required only one minute of training data to recognize six gestures across different cycling scenarios with high accuracy. A controlled conditions evaluation (N=8) shows MagFace's robustness against strong lighting, wind, bumpy roads, and uphills. Finally, an in-the-wild evaluation (N=14) shows the stable performance of MagFace's real-time system and demonstrates promising usability of MagFace.2026GWGuanyun Wang et al.Zhejiang UniversityHand Gesture RecognitionMotion Sickness & Passenger ExperienceContext-Aware ComputingCHI
TH-Wood: Developing Thermo-Hygro-Coordinating Driven Wood Actuators to Enhance Human-Nature InteractionWood has become increasingly applied in shape-changing interfaces for its eco-friendly and smart responsive properties, while its applications face challenges as it remains primarily driven by humidity. We propose TH-Wood, a biodegradable actuator system composed of wood veneer and microbial polymers, driven by both temperature and humidity, and capable of functioning in complex outdoor environments. This dual-factor-driven approach enhances the sensing and response channels, allowing for more sophisticated coordinating control methods. To assist in designing and utilizing the system more effectively, we developed a structure library inspired by dynamic plant forms, conducted extensive technical evaluations, created an educational platform accessible to users, and provided a design tool for deformation adjustments and behavior previews. Finally, several ecological applications demonstrate the potential of TH-Wood to significantly enhance human interaction with natural environments and expand the boundaries of human-nature relationships.2025GWGuanyun Wang et al.Zhejiang UniversityShape-Changing Interfaces & Soft Robotic MaterialsHuman-Nature Relationships (More-than-Human Design)CHI
Touch-n-Go: Designing and Fabricating Touch Fastening Structures by FDM 3D PrintingTouch 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.2024LSLingyun Sun et al.Zhejiang UniversityDesktop 3D Printing & Personal FabricationCustomizable & Personalized ObjectsCHI
All-in-One Print: Designing and 3D Printing Dynamic Objects Using Kinematic Mechanism Without AssemblyThe 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.2023JLJiaji Li et al.Zhejiang UniversityDesktop 3D Printing & Personal FabricationShape-Changing Materials & 4D PrintingCHI
4Doodle: 4D Printing Artifacts without 3D Printers4D 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.2023YTYe Tao et al.Zhejiang University City CollegeShape-Changing Interfaces & Soft Robotic MaterialsShape-Changing Materials & 4D PrintingDigital Art Installations & Interactive PerformanceCHI
X-Bridges: Designing Tunable Bridges to Enrich 3D Printed Objects' Deformation and StiffnessBridges 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.2022LSLingyun Sun et al.Desktop 3D Printing & Personal FabricationShape-Changing Materials & 4D PrintingUIST
Geodesy: Self-rising 2.5D Tiles by Printing along 2D Geodesic Closed PathThermoplastic and Fused Deposition Modeling (FDM) based 4D printing are rapidly expanding to allow for space- and material-saving 2D printed sheets morphing into 3D shapes when heated. However, to our knowledge, all the known examples are either origami-based models with obvious folding hinges, or beam-based models with holes on the morphing surfaces. Morphing continuous double-curvature surfaces remains a challenge, both in terms of a tailored toolpath-planning strategy and a computational model that simulates it. Additionally, neither approach takes surface texture as a design parameter in its computational pipeline. To extend the design space of FDM-based 4D printing, in Geodesy, we focus on the morphing of continuous double-curvature surfaces or surface textures. We suggest a unique tool path - printing thermoplastics along 2D closed geodesic paths to form a surface with one raised continuous double-curvature tiles when exposed to heat. The design space is further extended to more complex geometries composed of a network of rising tiles (i.e., surface textures). Both design components and the computational pipeline are explained in the paper, followed by several printed geometric examples.2019JGJianzhe Gu et al.Carnegie Mellon UniversityShape-Changing Interfaces & Soft Robotic MaterialsDesktop 3D Printing & Personal FabricationCHI
Morphlour: Personalized Flour-based Morphing Food Induced by Dehydration or Hydration MethodIn this paper, we explore personalized morphing food that enhances traditional food with new HCI capabilities, rather than replacing the chef and authentic ingredients (e.g., flour) with an autonomous machine and heterogeneous mixtures (e.g., gel). Thus, we contribute a unique transformation mechanism of kneaded and sheeted flour-based dough, with an integrated design strategy for morphing food during two general cooking methods: dehydration (e.g., baking) or hydration (e.g., water boiling). We also enrich the design space of morphing food by demonstrating several application cases. We end by discussing hybrid cooking between human and design tool to ensure accuracy while preserving customizability for morphing food.2019YTYe Tao et al.Human-Nature Relationships (More-than-Human Design)Food Culture & Food InteractionUIST
A-line: 4D Printing Morphing Linear Composite StructuresThis paper presents A-line, a 4D printing system for designing and fabricating morphing three-dimensional shapes out of simple linear elements. In addition to the commonly known benefit of 4D printing to save printing time, printing materials, and packaging space, A-line also takes advantage of the unique properties of thin lines, including their suitability for compliant mechanisms and ability to travel through narrow spaces and self-deploy or self-lock on site. A-line integrates a method of bending angle control in up to eight directions for one printed line segment, using a single type of thermoplastic material. A software platform to support the design, simulation and tool path generation is developed to support the design and manufacturing of various A-line structures. Finally, the design space of A-line is explored through four application areas, including line sculpting, compliant mechanisms, self-deploying, and self-locking structures.2019GWGuanyun Wang et al.Carnegie Mellon UniversityShape-Changing Interfaces & Soft Robotic MaterialsShape-Changing Materials & 4D PrintingCHI
Thermorph: Democratizing 4D Printing of Self-Folding Materials and InterfacesWe develop a novel method printing complex self-folding geometries. We demonstrated that with a desktop fused deposition modeling (FDM) 3D printer, off-the-shelf printing filaments and a design editor, we can print flat thermoplastic composites and trigger them to self-fold into 3D with arbitrary bending angles. This is a suitable technique, called Thermorph, to prototype hollow and foldable 3D shapes without losing key features. We describe a new curved folding origami design algorithm, compiling given arbitrary 3D models to 2D unfolded models in G-Code for FDM printers. To demonstrate the Thermorph platform, we designed and printed complex self-folding geometries (up to 70 faces), including 15 self-curved geometric primitives and 4 self-curved applications, such as chairs, the simplified Stanford Bunny and flowers. Compared to the standard 3D printing, our method saves up to 60% - 87% of the printing time for all shapes chosen.2018BAByoungkwon An et al.Carnegie Mellon University, Duke UniversityShape-Changing Materials & 4D PrintingCHI
Forte: User-Driven Generative DesignLow-cost fabrication machines (e.g., 3D printers) offer the promise of creating custom-designed objects by a range of users. To maximize performance, generative design methods such as topology optimization can automatically optimize properties of a design based on high-level specifications. Though promising, such methods require people to map their design ideas--often unintuitively--to a small number of mathematical input parameters, and the relationship between those parameters and a generated design is often unclear, making it difficult to iterate a design. We present Forte, a sketch-based, real-time interactive tool for people to directly express and iterate on their designs via 2D topology optimization. Users can ask the system to add structures, provide a variation with better performance, or optimize internal material layouts. Users can globally control how much to `deviate' from the initial sketch, or perform local suggestive editing, which interactively prompts the system to update based on the new information. Design sessions with 10 participants demonstrate that Forte empowers designers to create and explore a range of optimized designs with custom forms and styles.2018XCXiang 'Anthony' Chen et al.Carnegie Mellon UniversityDesktop 3D Printing & Personal FabricationCustomizable & Personalized ObjectsCHI
Printed Paper Actuator: A Low-cost Reversible Actuation and Sensing Method for Shape Changing InterfacesWe present a printed paper actuator as a low cost, reversible and electrical actuation and sensing method. This is a novel but easily accessible enabling technology that expands upon the library of actuation-sensing materials in HCI. By integrating three physical phenomena, including the bilayer bending actuation, the shape memory effect of the thermoplastic and the current-driven joule heating via conductive printing filament, we developed the actuator by simply printing a single layer conductive Polylactide (PLA) on a piece of copy paper via a desktop fused deposition modeling (FDM) 3D printer. This paper describes the fabrication process, the material mechanism, and the transformation primitives, followed by the electronic sensing and control methods. A software tool that assists the design, simulation and printing toolpath generation is introduced. Finally, we explored applications under four contexts: robotics, interactive art, entertainment and home environment.2018GWGuanyun Wang et al.Carnegie Mellon UniversityShape-Changing Interfaces & Soft Robotic MaterialsDesktop 3D Printing & Personal FabricationShape-Changing Materials & 4D PrintingCHI
4DMesh: 4D Printing Morphing Non-Developable Mesh SurfacesWe present 4DMesh, a method of combining shrinking and bending thermoplastic actuators with customized geometric algorithms to 4D print and morph centimeter- to meter-sized functional non-developable surfaces. We will share two end-to-end inverse design algorithms. With our tools, users can input CAD models of target surfaces and produce respective printable files. The flat sheet printed can morph into target surfaces when triggered by heat. This system saves shipping and packaging costs, in addition to enabling customizability for the design of relatively large non-developable structures. We designed a few functional artifacts to leverage the advantage of non-developable surfaces for their unique functionalities in aesthetics, mechanical strength, geometric ergonomics and other functionalities. In addition, we demonstrated how this technique can potentially be adapted to customize molds for industrial parts (e.g., car, boat, etc.) in the future.2018GWGuanyun Wang et al.Shape-Changing Interfaces & Soft Robotic MaterialsShape-Changing Materials & 4D PrintingUIST