Tag Archives: fabrication-reconfigurable-deployable

Programmable Matter

This work explores innovative ways to enhance the control, reliability, and fabrication of programmable matter systems—systems with the ability to change their shape or mechanical properties in a controllable manner. By investigating how to improve the controllability and scalability of programmable matter, we aim to unlock its potential for a wide range of applications, from responsive materials to reconfigurable devices.

Self Folding

Self-folding, a self-assembly process where a structure autonomously transforms from a flat sheet into a 3D shape, is a key focus in our exploration of programmable matter. Inspired by origami principles, self-folding offers significant advantages over traditional methods of rapid fabrication for 3D objects, such as reduced material waste and improved cost-efficiency. These structures are particularly well-suited for robotic systems, as they allow for the integration of multiple materials, including actuators and sensors, directly into the sheet. This essentially creates a flexible printed circuit board capable of performing robotic tasks with minimal wiring and manual assembly. The logistical benefits of self-folding systems have garnered significant interest, as these devices can be transported in a flat state and deployed autonomously into complex geometries at scales ranging from millimeters to centimeters.

Re-Programmable Matter

Reprogrammable matter systems open new possibilities for on-demand device customization. The ability to change shape provides a machine with adaptability and robustness and a potential for more efficient task execution. Imagine new computer displays that morph to show objects in full 3D rather than 2D images on a flat screen, resulting in new intuitive modes of virtual interaction. Or, everyday objects that autonomously morph their form: furniture that can serve alternately as chairs, tables, or shelves; smartphones that grow legs and crawl away, then shrink back to fit in a pocket; or cars that change their tire size or treads to suit the terrain.

MORF (Magnetic Origami Reprogramming and Folding System)

To move closer to this reality, our lab has developed an autonomous system for real-time reprogramming of self-assembling, shape-changing, and reusable structures using an origami-inspired approach and magnetic forces. This system controllably folds complex 3D structures through magnetic writing. MORF (Magnetic Origami Reprogramming and Folding System) enables repeatable, fully automated print-and-fold manufacturing of intricate 3D structures, naturally integrating active materials and electromechanical components. By precisely writing a magnetic program onto a laminate sheet at the millimeter scale, the sheet can be programmed and reprogrammed to fold and unfold into multiple shapes at various sizes and resolutions.

Most recently we haven shown how MORF has evolved into a fully reconfigurable platform for robotic and engineering applications by integrating a thin thermoplastic “locking” layer. When heated, this layer softens to allow folding under magnetic control; once cooled, it stiffens to preserve the desired shape with no need for continuous actuation. Through this approach these new structures withstand repeated folding and unfolding cycles and reliably bear loads of more than forty times their own weight. We demonstrate how this can serve as a reprogrammable robotic tool—switching between multiple grip sizes for bolts or screws on the fly—highlighting its potential for adaptive, on-demand manufacturing and assembly tasks.

Zooming out, we expect that magnetic program-and-fold technology will enable new levels of complexity and customization for future reprogrammable matter. Although we have focused in this system on only rigidly foldable patterns where the bending of the sheet is localized at the folds, the same techniques can be applied to applications requiring other types of sheet deformation, such as bending, torsion, or shear.

Heat Based

One method of self-folding involves utilizing a multi-layer structure, where a heat-sensitive contraction film (polyvinyl chloride; PVC) is sandwiched between two rigid structural layers. The self-folding crease patterns feature differentiated gap widths on the front and back faces. Upon heating, the difference in these widths causes the PVC to contract disproportionately, resulting in a bending motion that drives the folding process.

As the complexity of the folding pattern increases, so too does the likelihood of errors due to the multiple potential pathways the folds can take. To address these challenges, we are investigating the self-foldability of non-rigid origami patterns, such as the origami hyperbolic paraboloid (hypar), which is known for its symmetry and bistability.

Recent Publications

	Unger, Gabriel; Shenoy, Sridhar; Li, Tianyu; Figueroa, Nadia; Sung, Cynthia MORF: Magnetic Origami Reprogramming and Folding System for Repeatably Reconfigurable Structures with Fold Angle Control (Conference) IEEE International Conference on Robotics and Automation (ICRA), Forthcoming. (Abstract \| BibTeX \| Links: ) @conference{unger2025morf, title = {MORF: Magnetic Origami Reprogramming and Folding System for Repeatably Reconfigurable Structures with Fold Angle Control}, author = {Gabriel Unger and Sridhar Shenoy and Tianyu Li and Nadia Figueroa and Cynthia Sung }, url = {https://www.youtube.com/watch?v=mUDFZ6hfgWs https://repository.upenn.edu/entities/publication/0c5b8627-d270-455a-9a74-0bd136f28eaa }, year = {2025}, date = {2025-05-19}, urldate = {2025-05-19}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA)}, abstract = { We 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 re-programmability 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.}, keywords = {}, pubstate = {forthcoming}, tppubtype = {conference} } Close We 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 re-programmability 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. Close
	Unger, Gabriel; Sung, Cynthia Re-programmable Matter by Folding: Magnetically Controlled Origami that Self-Folds, Self-Unfolds, and Self-Reconfigures On-Demand (Conference) 8th International Meeting on Origami in Science, Mathematics, and Education, 2024. (Abstract \| BibTeX \| Links: ) @conference{unger2024RMBF, title = {Re-programmable Matter by Folding: Magnetically Controlled Origami that Self-Folds, Self-Unfolds, and Self-Reconfigures On-Demand}, author = {Gabriel Unger and Cynthia Sung}, url = {https://www.youtube.com/watch?v=TuIq6ykfoOA&list=PLmM-rbrIwkWXFno8GbQYxiCcA3s8SaVJW&index=1 https://repository.upenn.edu/entities/publication/18d39cb9-f453-4cc7-9a68-47ddcc4a2924}, year = {2024}, date = {2024-07-16}, urldate = {2024-07-16}, booktitle = {8th International Meeting on Origami in Science, Mathematics, and Education}, abstract = {We 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.}, keywords = {}, pubstate = {published}, tppubtype = {conference} } Close We 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. Close
	Liu, Addison; Johnson, Mykell; Sung, Cynthia Increasing Reliability of Self-Folding of the Origami Hypar (Journal Article) In: ASME Journal of Mechanisms and Robotics, vol. 14, no. 6, pp. 061003, 2022. (Abstract \| BibTeX \| Links: ) @article{liu2022increasing, title = {Increasing Reliability of Self-Folding of the Origami Hypar}, author = {Addison Liu and Mykell Johnson and Cynthia Sung}, doi = {10.1115/1.4054310}, year = {2022}, date = {2022-06-01}, urldate = {2022-06-01}, journal = {ASME Journal of Mechanisms and Robotics}, volume = {14}, number = {6}, pages = {061003}, abstract = {Self-folding systems, which can transform autonomously from a flat sheet into a 3D machine, provide opportunities for rapidly fabricable robots that are deployable on-demand. Existing self-folding fabrication processes convert fold patterns into laminated structures that respond to external stimuli, most commonly heat. However, demonstrations of these approaches have been generally limited to simple fold patterns with little ambiguity in folding configuration, and the reliability of self-folding drops drastically with the fold pattern complexity. In this paper, we explore methods of biasing a symmetric fold pattern, the origami hyperbolic paraboloid (hypar), to fold into one of two possible configurations. The biasing methods are simulated using a bar-and-hinge inspired self-folding model that defines a single fold as a bending beam and the hypar crease pattern as an elastic spring network. Simulation results are also verified on physical samples. Based on these results, three techniques to bias the hypar by manipulating the target fold angles are proposed and tested. The results show that biasing a self-folding pattern can increase folding accuracy from 50% (purely random) to 70%, and provide insights for improving the reliability of future self-folding systems with complex fold patterns.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Self-folding systems, which can transform autonomously from a flat sheet into a 3D machine, provide opportunities for rapidly fabricable robots that are deployable on-demand. Existing self-folding fabrication processes convert fold patterns into laminated structures that respond to external stimuli, most commonly heat. However, demonstrations of these approaches have been generally limited to simple fold patterns with little ambiguity in folding configuration, and the reliability of self-folding drops drastically with the fold pattern complexity. In this paper, we explore methods of biasing a symmetric fold pattern, the origami hyperbolic paraboloid (hypar), to fold into one of two possible configurations. The biasing methods are simulated using a bar-and-hinge inspired self-folding model that defines a single fold as a bending beam and the hypar crease pattern as an elastic spring network. Simulation results are also verified on physical samples. Based on these results, three techniques to bias the hypar by manipulating the target fold angles are proposed and tested. The results show that biasing a self-folding pattern can increase folding accuracy from 50% (purely random) to 70%, and provide insights for improving the reliability of future self-folding systems with complex fold patterns. Close
	Cha, Wujoon; Campbell, Matthew F.; Popov, George A.; Stanczak, Christopher H.; Estep, Anna K.; Steager, Edward B.; Sung, Cynthia R.; Yim, Mark H.; Bargatin, Igor Microfabricated foldable wings for centimeter-scale microflyers (Journal Article) In: Journal of Microelectromechanical Systems, vol. 29, no. 5, pp. 1127-1129, 2020. (Abstract \| BibTeX \| Links: ) @article{cha2020microfabricated, title = {Microfabricated foldable wings for centimeter-scale microflyers}, author = {Wujoon Cha and Matthew F. Campbell and George A. Popov and Christopher H. Stanczak and Anna K. Estep and Edward B. Steager and Cynthia R. Sung and Mark H. Yim and Igor Bargatin}, doi = {10.1109/JMEMS.2020.3013813}, year = {2020}, date = {2020-10-01}, urldate = {2020-10-01}, journal = {Journal of Microelectromechanical Systems}, volume = {29}, number = {5}, pages = {1127-1129}, abstract = {Many micro-aerial vehicles can benefit from having compact and robust pre-deployment configurations that can later transform into larger and more capable forms. We demonstrate parylene-covered silicon frames that can be folded into origami-inspired aerodynamic shapes for structural applications in centimeter-scale aircraft. By changing the spacing between the frames, we can control the conformality of the parylene deposition, which determines the directionality of the fold (mountain or valley). We fabricated a foldable propeller from such polymer-coated frames and characterized its mass and thrust.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Many micro-aerial vehicles can benefit from having compact and robust pre-deployment configurations that can later transform into larger and more capable forms. We demonstrate parylene-covered silicon frames that can be folded into origami-inspired aerodynamic shapes for structural applications in centimeter-scale aircraft. By changing the spacing between the frames, we can control the conformality of the parylene deposition, which determines the directionality of the fold (mountain or valley). We fabricated a foldable propeller from such polymer-coated frames and characterized its mass and thrust. Close
	Sung, Cynthia; Lin, Rhea; Miyashita, Shuhei; Yim, Sehyuk; Kim, Sangbae; Rus, Daniela Self-folded soft robotic structures with controllable joints (Conference) IEEE International Conference on Robotics and Automation (ICRA), 2017. (Abstract \| BibTeX \| Links: ) @conference{sung2017self, title = {Self-folded soft robotic structures with controllable joints}, author = {Cynthia Sung and Rhea Lin and Shuhei Miyashita and Sehyuk Yim and Sangbae Kim and Daniela Rus}, doi = {10.1109/ICRA.2017.7989072}, year = {2017}, date = {2017-05-29}, urldate = {2017-05-29}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA)}, pages = {580-587}, abstract = {This paper describes additive self-folding, an origami-inspired rapid fabrication approach for creating actuatable compliant structures. Recent work in 3-D printing and other rapid fabrication processes have mostly focused on rigid objects or objects that can achieve small deformations. In contrast, soft robots often require elastic materials and large amounts of movement. Additive self-folding is a process that involves cutting slices of a 3-D object in a long strip and then pleat folding them into a likeness of the original model. The zigzag pattern for folding enables large bending movements that can be actuated and controlled. Gaps between slices in the folded model can be designed to provide larger deformations or higher shape accuracy. We advance existing planar fabrication and self-folding techniques to automate the fabrication process, enabling highly compliant structures with complex 3-D geometries to be designed and fabricated within a few hours. We describe this process in this paper and provide algorithms for converting 3-D meshes into additive self-folding designs. The designs can be rapidly instrumented for global control using magnetic fields or tendon-driven for local bending. We also describe how the resulting structures can be modeled and their responses to tendon-driven control predicted. We test our design and fabrication methods on three models (a bunny, a tuna fish, and a starfish) and demonstrate the method's potential for actuation by actuating the tuna fish and starfish models using tendons and magnetic control.}, keywords = {}, pubstate = {published}, tppubtype = {conference} } Close This paper describes additive self-folding, an origami-inspired rapid fabrication approach for creating actuatable compliant structures. Recent work in 3-D printing and other rapid fabrication processes have mostly focused on rigid objects or objects that can achieve small deformations. In contrast, soft robots often require elastic materials and large amounts of movement. Additive self-folding is a process that involves cutting slices of a 3-D object in a long strip and then pleat folding them into a likeness of the original model. The zigzag pattern for folding enables large bending movements that can be actuated and controlled. Gaps between slices in the folded model can be designed to provide larger deformations or higher shape accuracy. We advance existing planar fabrication and self-folding techniques to automate the fabrication process, enabling highly compliant structures with complex 3-D geometries to be designed and fabricated within a few hours. We describe this process in this paper and provide algorithms for converting 3-D meshes into additive self-folding designs. The designs can be rapidly instrumented for global control using magnetic fields or tendon-driven for local bending. We also describe how the resulting structures can be modeled and their responses to tendon-driven control predicted. We test our design and fabrication methods on three models (a bunny, a tuna fish, and a starfish) and demonstrate the method's potential for actuation by actuating the tuna fish and starfish models using tendons and magnetic control. Close
	Miyashita, Shuhei; Guitron, Steven; Ludersdorfer, Marvin; Sung, Cynthia; Rus, Daniela An untethered miniature origami robot that self-folds, walks, swims, and degrades (Conference) IEEE International Conference on Robotics and Automation (ICRA), IEEE, 2015. (Abstract \| BibTeX \| Links: ) @conference{miyashita2015untethered, title = {An untethered miniature origami robot that self-folds, walks, swims, and degrades}, author = {Shuhei Miyashita and Steven Guitron and Marvin Ludersdorfer and Cynthia Sung and Daniela Rus}, doi = {10.1109/ICRA.2015.7139386}, year = {2015}, date = {2015-05-26}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA)}, pages = {1490-1496}, publisher = {IEEE}, abstract = {A miniature robotic device that can fold-up on the spot, accomplish tasks, and disappear by degradation into the environment promises a range of medical applications but has so far been a challenge in engineering. This work presents a sheet that can self-fold into a functional 3D robot, actuate immediately for untethered walking and swimming, and subsequently dissolve in liquid. The developed sheet weighs 0.31 g, spans 1.7 cm square in size, features a cubic neodymium magnet, and can be thermally activated to self-fold. Since the robot has asymmetric body balance along the sagittal axis, the robot can walk at a speed of 3.8 body-length/s being remotely controlled by an alternating external magnetic field. We further show that the robot is capable of conducting basic tasks and behaviors, including swimming, delivering/carrying blocks, climbing a slope, and digging. The developed models include an acetone-degradable version, which allows the entire robot's body to vanish in a liquid. We thus experimentally demonstrate the complete life cycle of our robot: self-folding, actuation, and degrading.}, keywords = {}, pubstate = {published}, tppubtype = {conference} } Close A miniature robotic device that can fold-up on the spot, accomplish tasks, and disappear by degradation into the environment promises a range of medical applications but has so far been a challenge in engineering. This work presents a sheet that can self-fold into a functional 3D robot, actuate immediately for untethered walking and swimming, and subsequently dissolve in liquid. The developed sheet weighs 0.31 g, spans 1.7 cm square in size, features a cubic neodymium magnet, and can be thermally activated to self-fold. Since the robot has asymmetric body balance along the sagittal axis, the robot can walk at a speed of 3.8 body-length/s being remotely controlled by an alternating external magnetic field. We further show that the robot is capable of conducting basic tasks and behaviors, including swimming, delivering/carrying blocks, climbing a slope, and digging. The developed models include an acetone-degradable version, which allows the entire robot's body to vanish in a liquid. We thus experimentally demonstrate the complete life cycle of our robot: self-folding, actuation, and degrading. Close
	Miyashita, Shuhei; DiDio, Isabello; Ananthabhotla, Ishwarya; An, Byoungkwon; Sung, Cynthia; Arabagi, Slava; Rus, Daniela Folding angle regulation by curved crease design for self-assembling origami propellers (Journal Article) In: ASME Journal of Mechanisms and Robotics, vol. 7, no. 2, pp. 021013, 2015. (Abstract \| BibTeX \| Links: ) @article{miyashita2015folding, title = {Folding angle regulation by curved crease design for self-assembling origami propellers}, author = {Shuhei Miyashita and Isabello DiDio and Ishwarya Ananthabhotla and Byoungkwon An and Cynthia Sung and Slava Arabagi and Daniela Rus}, doi = {10.1115/1.4029548}, year = {2015}, date = {2015-02-27}, journal = {ASME Journal of Mechanisms and Robotics}, volume = {7}, number = {2}, pages = {021013}, abstract = {This paper describes a method for manufacturing complex three-dimensional curved structures by self-folding layered materials. Our main focus is to first show that the material can cope with curved crease self-folding and then to utilize the curvature to predict the folding angles. The self-folding process employs uniform heat to induce self-folding of the material and shows the successful generation of several types of propellers as a proof of concept. We further show the resulting device is functional by demonstrating its levitation in the presence of a magnetic field applied remotely.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close This paper describes a method for manufacturing complex three-dimensional curved structures by self-folding layered materials. Our main focus is to first show that the material can cope with curved crease self-folding and then to utilize the curvature to predict the folding angles. The self-folding process employs uniform heat to induce self-folding of the material and shows the successful generation of several types of propellers as a proof of concept. We further show the resulting device is functional by demonstrating its levitation in the presence of a magnetic field applied remotely. Close

Current Personnel

Gabriel Unger (MEAM PhD)

Acknowledgements

This work was supported in part by the Army Research Office (ARO) under MURI Award #W911NF1810327, by NSF Grant1845339, NSF Grant No. 1659190, ONR Award #N00014-23-1-2068 and the Johnson & Johnson WiSTEM2D program, by the Penn Health-Tech program, and by the Penn Center for Undergraduate Research and Fellowships. Any opinions, findings, conclusions, or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the funding source.

Medical Application of Origami and Soft Robotic Systems

Our lab’s research in origami‐inspired robotics extends into the medical arena through collaborations with the University of Pennsylvania Hospital and the Children’s Hospital of Philadelphia, including partnerships with the Departments of Cardiology and Plastic Surgery. We also work closely with faculty such as Prof. Jordan Raney (MEAM) and Prof. Flavia Vitale (Penn’s Center for Neuroengineering & Therapeutics). These efforts focus on reconfigurable implants, artificial muscles, and soft actuators for medical devices.

A central goal is to develop origami-inspired soft actuators that function as artificial muscles, leveraging advanced fabrication techniques to enable compact, flexible, and highly robust motion. By incorporating principles such as multistability and bistability from origami, we design actuator systems that can be easily reconfigured yet remain strong enough to perform clinically relevant tasks. Our lab also leads work on mechanical characterization of origami-inspired tubular structures for use as reconfigurable implants, aiming to reduce surgical invasiveness by creating implantable devices (e.g., heart or bile duct stents) that can be adjusted noninvasively.

In parallel, our lab is developing algorithms and interactive design tools for kinematic mechanisms, with the goal of enabling the rapid and affordable creation of customized orthotics and prosthetics. These computational tools are intended to streamline the design process for patient-specific assistive devices, broadening access to personalized care.

MORF in Medical Applications
Our MORF (Magnetic Origami Reprogramming and Folding) System—initially developed for general reconfigurable devices—has proven especially promising for medical stents. Recently, in Penn’s Y-Prize competition, the 2025 winners “Stentix” proposed a magnetically reconfigurable biliary stent based on MORF. By using magnetic forces, this stent can be adjusted in position and diameter from outside the body, helping maintain bile flow without repeat endoscopies.

Related Publications

C. Kim, L. Yang, A. Anbuchelvan, R. Garg, N. Milbar, F. Vitale, and C. Sung, “Origami-Inspired Bistable Gripper with Self-Sensing Capabilities,” 2024 IEEE-RAS 7th International Conference on Soft Robotics (RoboSoft), San Diego, CA, USA, 2024 (Accepted)
B. Leung, G. Unger, S. Escorza, J. Chen, M. Fogel, and C. Sung, “Mechanical Characterization of an Origami-Inspired Multistable Tube for Reconfigurable Implants,” Poster at the Biomedical Engineering Society’s (BMES) Annual Meeting, 2023

Kim, Christopher; Yang, Lele; Anbuchelvan, Ashwath; Garg, Raghav; Milbar, Niv; Vitale, Flavia; Sung, Cynthia

Origami-Inspired Bistable Gripper with Self-Sensing Capabilities (Conference)

IEEE-RAS International Conference on Soft Robotics (Robosoft), 2024.

(Abstract | BibTeX | Links: )

Current Personnel

Christopher Kim (MEAM PhD)
Gabriel Unger (MEAM PhD)
Harita Trivedi (BE Undergrad)
Kylie Autullo (MEAM Undergrad)
Serena Carson (ROBO Master's)

Acknowledgments

This work was supported in part by the Johnson & Johnson WiSTEM2D program, by the Penn Health-Tech program, and by the Penn Center for Undergraduate Research and Fellowships. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of funding source.

Self-Sensing Actuators

Abstract

This project thrust introduces self-sensing actuators that merge actuation and sensing into a single component, enabling reductions in the size and weight of soft robots. Three self-sensing actuators—the I-cord knitted SMA (ICKS) actuator, the custom PET solenoid actuator from the Facial Reanimation and Bistable Gripper project, and a miniaturized tunable stiffness solenoid actuator—will showcase the self-sensing actuation capability.

Videos

I-cord Knitted SMA (ICKS) Actuator

Origami-Inspired Bistable Gripper with the Custom PET Solenoid Actuator

Ongoing Work

Medical Device Development: Medical implant device development with an abiotic bistable actuation mechanism and a self-sensing custom linear solenoid actuator
Magnetic Tunable Stiffness Spring: Tunable stiffness spring which utilizes the change in magnetic force on a self-sensing custom PET solenoid actuator

Publications

Kim, Christopher; Yang, Lele; Anbuchelvan, Ashwath; Garg, Raghav; Milbar, Niv; Vitale, Flavia; Sung, Cynthia

Origami-Inspired Bistable Gripper with Self-Sensing Capabilities (Conference)

IEEE-RAS International Conference on Soft Robotics (Robosoft), 2024.

(Abstract | BibTeX | Links: )

Kim, Christopher; Chien, Athena; Tippur, Megha; Sung, Cynthia

Fabrication and characterization of I-cord knitted SMA actuators (Conference)

IEEE International Conference on Soft Robotics (RoboSoft), 2021.

(Abstract | BibTeX | Links: )

People

Christopher Kim
Kylie Autullo
Lele Yang
Brianna Leung
Athena Chien
Megha Tippur

Acknowledgement

Support for the ICKS Actuator Project has been provided in part by NSF grant #EEC-1659190 and by the Johnson \& Johnson WiSTEM2D program.

Support for the Custom PET Solenoid Actuator Project has been provided in part by the University of Pennsylvania through the Center for Precision Engineering for Health, Edwin and Fannie Gray Hall Center for Human Appearance Research and Education Fund, Penn Center for Undergraduate Research and Fellowships, and National Institutes of Health (Award No. R01AR081062 to F.V.).

CurveQuad: A Centimeter-Scale Origami Quadruped that Leverages Curved Creases to Self-Fold and Crawl with One Motor

Abstract

We present CurveQuad, a miniature curved origami quadruped that is able to self-fold and unfold, crawl, and steer, all using a single actuator. CurveQuad is designed for planar manufacturing, with parts that attach and stack sequentially on a flat body. The design uses 4 curved creases pulled by 2 pairs of tendons from opposite ends of a link on a 270deg servo. It is 8 cm in the longest direction and weighs 10.9 g. Rotating the horn pulls the tendons inwards to induce folding. Continuing to rotate the horn shears the robot, enabling the robot to shuffle forward while turning in either direction. We experimentally validate the robot’s ability to fold, steer, and unfold by changing the magnitude of horn rotation. We also demonstrate basic feedback control by steering towards a light source from a variety of starting positions and orientations, and swarm aggregation by having 4 robots simultaneously steer towards the light. The results demonstrate the potential of using curved crease origami in self-assembling and deployable robots with complex motions such as locomotion.

Publisher source: https://ieeexplore.ieee.org/document/10342339

Paper full text: https://repository.upenn.edu/handle/20.500.14332/58861

Fabrication Files

Laser Cut Files

3D Print Files

Battery and Servo mount: upper piece attaching to servo, lower piece holding battery, spacer
Servo Horn: upper piece attaching to servo, middle bar, lower cap

Circuit Design Files

Gerber files
EAGLE files: sch, brd, lbr

Funding Support

The work was supported in part by the Army Research Office (ARO) under MURI Award #W911NF1810327, by NSF Grant #1845339, by the Johnson & Johnson WiSTEM2D Scholars Program, and by ONR Award #N00014-23-1-2068. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of these organizations.

Reference this work:

Daniel Feshbach, Xuelin Wu, Satviki Vasireddy, Louis Beardell, Bao To, Yuliy Baryshnikov, Cynthia Sung: CurveQuad: A centimeter-scale origami quadruped that leverages curved creases to self-fold and crawl with one motor. IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2023.

BibTeX (Download)

@conference{feshbach2023curvequad,
title = {CurveQuad: A centimeter-scale origami quadruped that leverages curved creases to self-fold and crawl with one motor},
author = {Daniel Feshbach and Xuelin Wu and Satviki Vasireddy and Louis Beardell and Bao To and Yuliy Baryshnikov and Cynthia Sung},
url = {https://www.youtube.com/watch?v=RnSHG5F2Iek&ab_channel=SungRoboticsGroup
https://sung.seas.upenn.edu/publications/curvequad/},
doi = {10.1109/IROS55552.2023.10342339},
year  = {2023},
date = {2023-10-01},
urldate = {2023-10-01},
booktitle = {IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)},
abstract = {We present CurveQuad, a miniature curved origami quadruped that is able to self-fold and unfold, crawl, and steer, all using a single actuator. CurveQuad is designed for planar manufacturing, with parts that attach and stack sequentially on a flat body. The design uses 4 curved creases pulled by 2 pairs of tendons from opposite ends of a link on a 270deg servo. It is 8 cm in the longest direction and weighs 10.9 g. Rotating the horn pulls the tendons inwards to induce folding. Continuing to rotate the horn shears the robot, enabling the robot to shuffle forward while turning in either direction. We experimentally validate the robot’s ability to fold, steer, and unfold by changing the magnitude of horn rotation. We also demonstrate basic feedback control by steering towards a light source from a variety of starting positions and orientations, and swarm aggregation by having 4 robots simultaneously steer towards the light. The results demonstrate the potential of using curved crease origami in self-assembling and deployable robots with complex motions such as locomotion.},
keywords = {2023, origami, self-folding},
pubstate = {published},
tppubtype = {conference}
}

	Unger, Gabriel; Shenoy, Sridhar; Li, Tianyu; Figueroa, Nadia; Sung, Cynthia MORF: Magnetic Origami Reprogramming and Folding System for Repeatably Reconfigurable Structures with Fold Angle Control (Conference) IEEE International Conference on Robotics and Automation (ICRA), Forthcoming. (Abstract \| BibTeX \| Links: ) @conference{unger2025morf, title = {MORF: Magnetic Origami Reprogramming and Folding System for Repeatably Reconfigurable Structures with Fold Angle Control}, author = {Gabriel Unger and Sridhar Shenoy and Tianyu Li and Nadia Figueroa and Cynthia Sung }, url = {https://www.youtube.com/watch?v=mUDFZ6hfgWs https://repository.upenn.edu/entities/publication/0c5b8627-d270-455a-9a74-0bd136f28eaa }, year = {2025}, date = {2025-05-19}, urldate = {2025-05-19}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA)}, abstract = { We 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 re-programmability 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.}, keywords = {}, pubstate = {forthcoming}, tppubtype = {conference} } Close We 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 re-programmability 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. Close
	Unger, Gabriel; Sung, Cynthia Re-programmable Matter by Folding: Magnetically Controlled Origami that Self-Folds, Self-Unfolds, and Self-Reconfigures On-Demand (Conference) 8th International Meeting on Origami in Science, Mathematics, and Education, 2024. (Abstract \| BibTeX \| Links: ) @conference{unger2024RMBF, title = {Re-programmable Matter by Folding: Magnetically Controlled Origami that Self-Folds, Self-Unfolds, and Self-Reconfigures On-Demand}, author = {Gabriel Unger and Cynthia Sung}, url = {https://www.youtube.com/watch?v=TuIq6ykfoOA&list=PLmM-rbrIwkWXFno8GbQYxiCcA3s8SaVJW&index=1 https://repository.upenn.edu/entities/publication/18d39cb9-f453-4cc7-9a68-47ddcc4a2924}, year = {2024}, date = {2024-07-16}, urldate = {2024-07-16}, booktitle = {8th International Meeting on Origami in Science, Mathematics, and Education}, abstract = {We 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.}, keywords = {}, pubstate = {published}, tppubtype = {conference} } Close We 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. Close
	Liu, Addison; Johnson, Mykell; Sung, Cynthia Increasing Reliability of Self-Folding of the Origami Hypar (Journal Article) In: ASME Journal of Mechanisms and Robotics, vol. 14, no. 6, pp. 061003, 2022. (Abstract \| BibTeX \| Links: ) @article{liu2022increasing, title = {Increasing Reliability of Self-Folding of the Origami Hypar}, author = {Addison Liu and Mykell Johnson and Cynthia Sung}, doi = {10.1115/1.4054310}, year = {2022}, date = {2022-06-01}, urldate = {2022-06-01}, journal = {ASME Journal of Mechanisms and Robotics}, volume = {14}, number = {6}, pages = {061003}, abstract = {Self-folding systems, which can transform autonomously from a flat sheet into a 3D machine, provide opportunities for rapidly fabricable robots that are deployable on-demand. Existing self-folding fabrication processes convert fold patterns into laminated structures that respond to external stimuli, most commonly heat. However, demonstrations of these approaches have been generally limited to simple fold patterns with little ambiguity in folding configuration, and the reliability of self-folding drops drastically with the fold pattern complexity. In this paper, we explore methods of biasing a symmetric fold pattern, the origami hyperbolic paraboloid (hypar), to fold into one of two possible configurations. The biasing methods are simulated using a bar-and-hinge inspired self-folding model that defines a single fold as a bending beam and the hypar crease pattern as an elastic spring network. Simulation results are also verified on physical samples. Based on these results, three techniques to bias the hypar by manipulating the target fold angles are proposed and tested. The results show that biasing a self-folding pattern can increase folding accuracy from 50% (purely random) to 70%, and provide insights for improving the reliability of future self-folding systems with complex fold patterns.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Self-folding systems, which can transform autonomously from a flat sheet into a 3D machine, provide opportunities for rapidly fabricable robots that are deployable on-demand. Existing self-folding fabrication processes convert fold patterns into laminated structures that respond to external stimuli, most commonly heat. However, demonstrations of these approaches have been generally limited to simple fold patterns with little ambiguity in folding configuration, and the reliability of self-folding drops drastically with the fold pattern complexity. In this paper, we explore methods of biasing a symmetric fold pattern, the origami hyperbolic paraboloid (hypar), to fold into one of two possible configurations. The biasing methods are simulated using a bar-and-hinge inspired self-folding model that defines a single fold as a bending beam and the hypar crease pattern as an elastic spring network. Simulation results are also verified on physical samples. Based on these results, three techniques to bias the hypar by manipulating the target fold angles are proposed and tested. The results show that biasing a self-folding pattern can increase folding accuracy from 50% (purely random) to 70%, and provide insights for improving the reliability of future self-folding systems with complex fold patterns. Close
	Cha, Wujoon; Campbell, Matthew F.; Popov, George A.; Stanczak, Christopher H.; Estep, Anna K.; Steager, Edward B.; Sung, Cynthia R.; Yim, Mark H.; Bargatin, Igor Microfabricated foldable wings for centimeter-scale microflyers (Journal Article) In: Journal of Microelectromechanical Systems, vol. 29, no. 5, pp. 1127-1129, 2020. (Abstract \| BibTeX \| Links: ) @article{cha2020microfabricated, title = {Microfabricated foldable wings for centimeter-scale microflyers}, author = {Wujoon Cha and Matthew F. Campbell and George A. Popov and Christopher H. Stanczak and Anna K. Estep and Edward B. Steager and Cynthia R. Sung and Mark H. Yim and Igor Bargatin}, doi = {10.1109/JMEMS.2020.3013813}, year = {2020}, date = {2020-10-01}, urldate = {2020-10-01}, journal = {Journal of Microelectromechanical Systems}, volume = {29}, number = {5}, pages = {1127-1129}, abstract = {Many micro-aerial vehicles can benefit from having compact and robust pre-deployment configurations that can later transform into larger and more capable forms. We demonstrate parylene-covered silicon frames that can be folded into origami-inspired aerodynamic shapes for structural applications in centimeter-scale aircraft. By changing the spacing between the frames, we can control the conformality of the parylene deposition, which determines the directionality of the fold (mountain or valley). We fabricated a foldable propeller from such polymer-coated frames and characterized its mass and thrust.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Many micro-aerial vehicles can benefit from having compact and robust pre-deployment configurations that can later transform into larger and more capable forms. We demonstrate parylene-covered silicon frames that can be folded into origami-inspired aerodynamic shapes for structural applications in centimeter-scale aircraft. By changing the spacing between the frames, we can control the conformality of the parylene deposition, which determines the directionality of the fold (mountain or valley). We fabricated a foldable propeller from such polymer-coated frames and characterized its mass and thrust. Close
	Sung, Cynthia; Lin, Rhea; Miyashita, Shuhei; Yim, Sehyuk; Kim, Sangbae; Rus, Daniela Self-folded soft robotic structures with controllable joints (Conference) IEEE International Conference on Robotics and Automation (ICRA), 2017. (Abstract \| BibTeX \| Links: ) @conference{sung2017self, title = {Self-folded soft robotic structures with controllable joints}, author = {Cynthia Sung and Rhea Lin and Shuhei Miyashita and Sehyuk Yim and Sangbae Kim and Daniela Rus}, doi = {10.1109/ICRA.2017.7989072}, year = {2017}, date = {2017-05-29}, urldate = {2017-05-29}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA)}, pages = {580-587}, abstract = {This paper describes additive self-folding, an origami-inspired rapid fabrication approach for creating actuatable compliant structures. Recent work in 3-D printing and other rapid fabrication processes have mostly focused on rigid objects or objects that can achieve small deformations. In contrast, soft robots often require elastic materials and large amounts of movement. Additive self-folding is a process that involves cutting slices of a 3-D object in a long strip and then pleat folding them into a likeness of the original model. The zigzag pattern for folding enables large bending movements that can be actuated and controlled. Gaps between slices in the folded model can be designed to provide larger deformations or higher shape accuracy. We advance existing planar fabrication and self-folding techniques to automate the fabrication process, enabling highly compliant structures with complex 3-D geometries to be designed and fabricated within a few hours. We describe this process in this paper and provide algorithms for converting 3-D meshes into additive self-folding designs. The designs can be rapidly instrumented for global control using magnetic fields or tendon-driven for local bending. We also describe how the resulting structures can be modeled and their responses to tendon-driven control predicted. We test our design and fabrication methods on three models (a bunny, a tuna fish, and a starfish) and demonstrate the method's potential for actuation by actuating the tuna fish and starfish models using tendons and magnetic control.}, keywords = {}, pubstate = {published}, tppubtype = {conference} } Close This paper describes additive self-folding, an origami-inspired rapid fabrication approach for creating actuatable compliant structures. Recent work in 3-D printing and other rapid fabrication processes have mostly focused on rigid objects or objects that can achieve small deformations. In contrast, soft robots often require elastic materials and large amounts of movement. Additive self-folding is a process that involves cutting slices of a 3-D object in a long strip and then pleat folding them into a likeness of the original model. The zigzag pattern for folding enables large bending movements that can be actuated and controlled. Gaps between slices in the folded model can be designed to provide larger deformations or higher shape accuracy. We advance existing planar fabrication and self-folding techniques to automate the fabrication process, enabling highly compliant structures with complex 3-D geometries to be designed and fabricated within a few hours. We describe this process in this paper and provide algorithms for converting 3-D meshes into additive self-folding designs. The designs can be rapidly instrumented for global control using magnetic fields or tendon-driven for local bending. We also describe how the resulting structures can be modeled and their responses to tendon-driven control predicted. We test our design and fabrication methods on three models (a bunny, a tuna fish, and a starfish) and demonstrate the method's potential for actuation by actuating the tuna fish and starfish models using tendons and magnetic control. Close
	Miyashita, Shuhei; Guitron, Steven; Ludersdorfer, Marvin; Sung, Cynthia; Rus, Daniela An untethered miniature origami robot that self-folds, walks, swims, and degrades (Conference) IEEE International Conference on Robotics and Automation (ICRA), IEEE, 2015. (Abstract \| BibTeX \| Links: ) @conference{miyashita2015untethered, title = {An untethered miniature origami robot that self-folds, walks, swims, and degrades}, author = {Shuhei Miyashita and Steven Guitron and Marvin Ludersdorfer and Cynthia Sung and Daniela Rus}, doi = {10.1109/ICRA.2015.7139386}, year = {2015}, date = {2015-05-26}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA)}, pages = {1490-1496}, publisher = {IEEE}, abstract = {A miniature robotic device that can fold-up on the spot, accomplish tasks, and disappear by degradation into the environment promises a range of medical applications but has so far been a challenge in engineering. This work presents a sheet that can self-fold into a functional 3D robot, actuate immediately for untethered walking and swimming, and subsequently dissolve in liquid. The developed sheet weighs 0.31 g, spans 1.7 cm square in size, features a cubic neodymium magnet, and can be thermally activated to self-fold. Since the robot has asymmetric body balance along the sagittal axis, the robot can walk at a speed of 3.8 body-length/s being remotely controlled by an alternating external magnetic field. We further show that the robot is capable of conducting basic tasks and behaviors, including swimming, delivering/carrying blocks, climbing a slope, and digging. The developed models include an acetone-degradable version, which allows the entire robot's body to vanish in a liquid. We thus experimentally demonstrate the complete life cycle of our robot: self-folding, actuation, and degrading.}, keywords = {}, pubstate = {published}, tppubtype = {conference} } Close A miniature robotic device that can fold-up on the spot, accomplish tasks, and disappear by degradation into the environment promises a range of medical applications but has so far been a challenge in engineering. This work presents a sheet that can self-fold into a functional 3D robot, actuate immediately for untethered walking and swimming, and subsequently dissolve in liquid. The developed sheet weighs 0.31 g, spans 1.7 cm square in size, features a cubic neodymium magnet, and can be thermally activated to self-fold. Since the robot has asymmetric body balance along the sagittal axis, the robot can walk at a speed of 3.8 body-length/s being remotely controlled by an alternating external magnetic field. We further show that the robot is capable of conducting basic tasks and behaviors, including swimming, delivering/carrying blocks, climbing a slope, and digging. The developed models include an acetone-degradable version, which allows the entire robot's body to vanish in a liquid. We thus experimentally demonstrate the complete life cycle of our robot: self-folding, actuation, and degrading. Close
	Miyashita, Shuhei; DiDio, Isabello; Ananthabhotla, Ishwarya; An, Byoungkwon; Sung, Cynthia; Arabagi, Slava; Rus, Daniela Folding angle regulation by curved crease design for self-assembling origami propellers (Journal Article) In: ASME Journal of Mechanisms and Robotics, vol. 7, no. 2, pp. 021013, 2015. (Abstract \| BibTeX \| Links: ) @article{miyashita2015folding, title = {Folding angle regulation by curved crease design for self-assembling origami propellers}, author = {Shuhei Miyashita and Isabello DiDio and Ishwarya Ananthabhotla and Byoungkwon An and Cynthia Sung and Slava Arabagi and Daniela Rus}, doi = {10.1115/1.4029548}, year = {2015}, date = {2015-02-27}, journal = {ASME Journal of Mechanisms and Robotics}, volume = {7}, number = {2}, pages = {021013}, abstract = {This paper describes a method for manufacturing complex three-dimensional curved structures by self-folding layered materials. Our main focus is to first show that the material can cope with curved crease self-folding and then to utilize the curvature to predict the folding angles. The self-folding process employs uniform heat to induce self-folding of the material and shows the successful generation of several types of propellers as a proof of concept. We further show the resulting device is functional by demonstrating its levitation in the presence of a magnetic field applied remotely.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close This paper describes a method for manufacturing complex three-dimensional curved structures by self-folding layered materials. Our main focus is to first show that the material can cope with curved crease self-folding and then to utilize the curvature to predict the folding angles. The self-folding process employs uniform heat to induce self-folding of the material and shows the successful generation of several types of propellers as a proof of concept. We further show the resulting device is functional by demonstrating its levitation in the presence of a magnetic field applied remotely. Close