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Publication MORF: Magnetic Origami Reprogramming and Folding System for Repeatably Reconfigurable Structures with Fold Angle Control(IEEE, 2025-05-19) Unger, Gabriel; Shenoy, Sridhar; Li, Tianyu; Figueroa, Nadia; Sung, CynthiaWe present the Magnetic Origami Reprogramming and Folding System (MORF), a magnetically reprogrammable system capable of precise shape control, repeated transformations, and adaptive functionality for robotic applications. Unlike current self-folding systems, which often lack reprogrammability or lose rigidity after folding, MORF generates stiff structures over multiple folding cycles without degradation in performance. The ability to reconfigure and maintain structural stability is crucial for tasks such as reconfigurable tooling. The system utilizes a thermoplastic layer sandwiched within a thin magnetically responsive laminate sheet, enabling structures to self-fold in response to a combination of external magnetic field and heating. We demonstrate that the resulting folded structures can bear loads over 40 times their own weight and can undergo up to 50 cycles of repeated transformations without losing structural integrity. We showcase these strengths in a reconfigurable tool for unscrewing and screwing bolts and screws of various sizes, allowing the tool to adapt its shape to different bolt sizes while withstanding the mechanical stresses involved. This capability highlights the system’s potential for task-varying, load-bearing applications in robotics, where both versatility and durability are essential.Publication Supplementary Materials: Reparametrization of 3D CSC Dubins Paths Enabling 2D Search(2024-10-08) Ling Xu; Yuliy Baryshnikov; Cynthia Sung; Sung, CynthiaThis paper addresses the Dubins path planning problem for vehicles in 3D space. In particular, we consider the problem of computing CSC paths – paths that consist of a circular arc (C) followed by a straight segment (S) followed by a circular arc (C). These paths are useful for vehicles such as fixed-wing aircraft and underwater submersibles that are subject to lower bounds on turn radius. We present a new parameterization that reduces the 3D CSC planning problem to a search over 2 variables, thus lowering search complexity, while also providing gradients that assist that search. We use these equations with a numerical solver to explore numbers and types of solutions computed for a variety of planar and 3D scenarios. Our method successfully computes CSC paths for the large majority of test cases, indicating that it could be useful for future generation of robust, efficient curvature-constrained trajectories.Publication Effect of Jet Coordination on Underwater Propulsion with the Multi-Robot SALP System(2025-04) Yang, Zhiyuan; Zhang, Yipeng; Herbert, Matthew; Hsieh, Mong-ying A; Sung, CynthiaSalps, marine invertebrates known for their collective swimming through coordinated jet propulsion, offer a unique model for efficient underwater movement. Inspired by this biological system, we develop the SALP (Salp-inspired Approach to Low-energy Propulsion) robot, a soft underwater robot that swims via jet propulsion similarly to a biological salp. The SALPs can be physically connected into SALP chains and coordinate their jets to achieve various propulsion modes. In our experiments, we compare the swimming performance of the individual SALP with the two-SALP system, focusing on power, acceleration, velocity, and energy efficiency. Results indicate that two SALPs swimming synchronously exhibit a 9.0% increase in steady-state velocity and a 16.6% improvement in transient acceleration compared to a single SALP. Additionally, our analysis of swimming efficiency implies that asynchronous swimming is potentially more energy efficient than the synchronous mode, as reflected by a decrease in the cost of transport (COT).Publication Supplementary Materials: Algorithmic Design of Kinematic Trees Based on CSC Dubins Planning for Link Shapes(2024-10-08) Feshbach, Daniel Adam; Chen, Wei-Hsi; Xu, Ling; Schaumburg, Emil; Huang, Isabella; Sung, CynthiaSupplementary materials for the paper "Algorithmic Design of Kinematic Trees Based on CSC Dubins Planning for Link Shapes", presented at The 16th International Workshop on the Algorithmic Foundations of Robotics (WAFR), 2024. Paper abstract: Computational tools for robot design require algorithms moving between several layers of abstraction including task, morphology, kinematics, mechanism shapes, and actuation. In this paper we give a linear-time algorithm mapping from kinematics to mechanism shape for tree-structured linkages. Specifically, we take as input a tree whose nodes are axes of motion (lines which joints rotate about or translate along) along with types and sizes for joints on these axes, and a radius r for a tubular bound on the link shapes. Our algorithm outputs the geometry for a kinematic tree instantiating these specifications such that the neutral configuration has no self-intersection. The algorithm approach is based on understanding the mechanism design problem as a planning problem for link shapes, and arranging the joints along their axes of motion to be appropriately spaced and oriented such that feasible, non-intersecting paths exist linking them. Since link bending is restricted by its tubular radius, this is a Dubins planning problem, and to prove the correctness of our algorithm we also prove a theorem about Dubins paths: if two point-direction pairs are separated by a plane at least 2r from each, and the directions each have non-negative dot product with the plane normal, then they are connected by a radius-r CSC Dubins path with turn angles <= pi. We implement our design algorithm in code and provide a 3D printed example of a tubular kinematic tree. The results provide an existence proof of tubular-shaped kinematic trees implementing given axes of motion, and could be used as a starting point for further optimization in an automated or algorithm-assisted robot design system.Publication Kinegami: Open-source Software for Creating Kinematic Chains from Tubular Origami(Springer, 2024-07-16) Feshbach, Daniel AdamArms, legs, and fingers of animals and robots are all examples of “kinematic chains" - mechanisms with sequences of joints connected by effectively rigid links. Lightweight kinematic chains can be manufactured quickly and cheaply by folding tubes. In recent work [Chen et al. 2023], we demonstrated that origami patterns for kinematic chains with arbitrary numbers of degrees of freedom can be constructed algorithmically from a minimal kinematic specification (axes that joints rotate about or translate along). The work was founded on a catalog of tubular crease patterns for revolute joints (rotation about an axis), prismatic joints (translation along an axis), and links, which compose to form the specified design. With this paper, we release an open-source python implementation of these patterns and algorithms. Users can specify kinematic chains as a sequence of degrees of freedom or by specific joint locations and orientations. Our software uses this information to construct a single crease pattern for the corresponding chain. The software also includes functions to move or delete joints in an existing chain and regenerate the connecting links, and a visualization tool so users can check that the chain can achieve their desired configurations. This paper provides a detailed guide to the code and its usage, including an explanation of our proposed representation for tubular crease patterns. We include a number of examples to illustrate the software’s capabilities and its potential for robot and mechanism design.Publication Re-programmable Matter by Folding: Magnetically Controlled Origami that Self-Folds, Self-Unfolds, and Self-Reconfigures On-Demand(Springer, 2024-07-24) Unger, Gabriel; Sung, CynthiaWe present a reprogrammable matter system that changes shape in a controllable manner in real-time and on-demand. The system uses origami inspired fabrication for self-assembly and repeated self-reconfiguration. By writing a magnetic program onto a thin laminate and applying an external magnetic field, we control the sheet to self-fold. The magnetic program can be written at millimeter resolution over hundreds of programming cycles and folding steps. We demonstrate how the same sheet can fold and unfold into multiple shapes using a fully automated program-and-fold process. Finally, we demonstrate how electronic components can be incorporated to produce functional structures such as a foldable display. The system has advantages over existing programmable matter systems in its versatility and ability to support potentially any folding sequence.Publication RAPID FABRICATION OF CUSTOMIZABLE MXENE/POLYDOPAMINE (MXPDA) ELECTRODES(2024-05-17) Daryl HurwitzIn the evolving field of neuroelectronics implants, several significant challenges persist. The rigidity of traditional devices often lead to substantial tissue damage and immune reactions, highlighting the urgent need for flexible, biomimetic designs that integrate more harmoniously with neural tissues, thereby enhancing biocompatibility and long-term stability. Most commercial neural implants are not customizable and feature a limited number of electrodes, which constrains the scope of neural data that can be captured. This limitation calls for the development of scalable technologies that can achieve higher spatial resolutions. Efficient wireless power and data transfer technologies are also essential to support fully implantable, untethered neural interfaces. Current implants generally lack the ability to incorporate multiple recording and stimulation modalities, restricting their application in diverse scientific studies. The development of multimodal interfaces could address this limitation, enabling more detailed studies of neural structure and function. This thesis explores the innovative use of MXene, specifically the two-dimensional nanomaterial TI3C2Tx, in conjunction with polydopamine (PDA) to develop customizable microelectrode arrays (MEAs) that can be rapidly fabricated for use in surgical settings. MXenes are selected for their exceptional conductivity, flexibility, and biocompatibility-qualities essential for effective neural interfaces. The addition of PDA enhances these interfaces’ mechanical and environmental stability while maintaining their excellent electrical properties. This research presents a novel method for the quick production of MEAs that can be adapted to individual surgical requirements potentially a day prior to or on the day of surgery, ultimately facilitating precise electrode placement for optimized neural recording and stimulation. By addressing the significant challenges of existing bioelectronic interfaces—such as the need for stable, safe, and functional integration with soft biological tissues—this thesis demonstrates a scalable approach to fabricate devices that combine the unique optical, electronic, and biocompatible properties of carbon-based nanomaterials. The outcomes of this work are expected to contribute significantly to the fields of neurology and bioelectronics by providing a robust platform for the advanced study of brain function across various spatial and temporal scales. This could lead to improved understanding and management of neurological conditions, thereby aligning with the broader goals of advancing neuroscientific research and clinical neurology.Publication Origami-Inspired Bistable Gripper with Self-Sensing Capabilities(7th IEEE-RAS International Conference on Soft Robotics (Robosoft) 2024, 2024-04) Kim, Christopher Y; Yang, Lele; Anbuchelvan, Ashwath; Garg, Raghav; Milbar, Niv; Vitale, Flavia; Sung, CynthiaAn origami-inspired bistable gripper, featuring a dual-function custom PET linear solenoid actuator that acts both as an actuator and a sensor, is presented. Movements in the permanent magnet plunger, which is directly mounted to the gripper, create induced electromotive force (emf) in the solenoid, and these induced emf measurements are used to detect snap-through actions and light contacts on the gripper. The fabrication methods for the gripper, actuator, and a gel-free soft wearable EMG electrode are outlined, and the actuator’s self-sensing method utilizing the time-integral of the induced emf measurements are explored. Because a self-sensing actuator eliminates the need for extra sensors, it allows for further miniaturization of the robot while maintaining its compactness and lightweight design. The paper also introduces a full humanin- the-loop system, allowing users to open or close the gripper with their biceps via a wearable EMG electrode. This system bridges human intent with robotic action, offering a more intuitive interaction model for robotic control.Publication Online Optimization of Soft Manipulator Mechanics via Hierarchical Control(2024) Misra, Shivangi; Sung, CynthiaActively tuning mechanical properties in soft robots is now feasible due to advancements in soft actuation technologies. In soft manipulators, these novel actuators can be distributed over the robot body to allow greater control over its large number of degrees of freedom and to stabilize local deformations against a range of disturbances. In this paper, we present a hierarchical policy for stiffness control for such a class of soft manipulators. The stiffness changes induce desired deformations in each segment, thereby influencing the manipulator’s end-effector position. The algorithm can be run as an online controller to influence the manipulator’s stable states – as we demonstrate in simulation – or offline as a design algorithm to optimize stiffness distributions – as we showcase in a hardware demonstration. Our proposed hierarchical control scheme is agnostic to the stiffness actuation method and can extend to other soft manipulators with nonuniform stiffness distributions.Publication ELECTRONICS DESIGN AND VERIFICATION FOR ROBOTS WITH ACTUATION AND SENSING REQUIREMENTS(ASME, 2023-08-29) Chen, Dongsheng; Huang, Zonghao; Sung, CynthiaRobot design is a challenging problem involving a balance between the robot’s mechanical design, kinematic structure, and actuation and sensing capabilities. Recentwork in computational robot design has focused on mechanical design while assuming that the given actuators are sufficient for the task. At the same time, existing electronics design tools ignore the physical requirements of the actuators and sensors in the circuit. In this paper, we present the first system that closes the loop between the two, incorporating a robot’s mechanical requirements into its circuit design process. We show that the problem can be solved using an iterative search consisting of two parts. First, a dynamic simulator converts the mechanical design and the given task into concrete actuation and sensing requirements. Second, a circuit generator executes a branch-and-bound search to convert the design requirements into a feasible electronic design. The system iterates through both of these steps, a process that is sometimes required since the electronics components add mass that may affect the robot’s design requirements. We demonstrate this approach on two examples – a manipulator and a quadruped – showing in both cases that the system is able to generate a valid electronics design.