Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userFiber-based shape-morphing architectures
63
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We describe a combined experimental and theoretical investigation of shape-morphing structures assembled by actuating composite (Janus) fibers, taking into account multiple relevant factors affecting shape transformations, such as strain rate, composition, and geometry of the structures. Starting with simple bending experiments, we demonstrate the ways to attain multiple out-of-plane shapes of closed rings and square frames. Through combining theory and simulation, we examine how the mechanical properties of Janus fibers affect shape transitions. This allows us to control shape changes and to attain target 3D shapes by precise tuning of the material properties and geometry of the fibers. Our results open new perspectives of design of advanced mechanical metamaterials capable to create elaborate structures through sophisticated actuation modes.
rate research
Read More
Shape morphing magnetic soft materials, composed of magnetic particles in a soft polymer matrix, can transform shapes reversibly, remotely, and rapidly, finding diverse applications in actuators, soft robotics, and biomedical devices. To achieve on-demand and sophisticated shape morphing, the manufacturing of structures with complex geometry and magnetization distribution is highly desired. Here, we report a magnetic dynamic polymer composite composed of hard-magnetic microparticles in a dynamic polymer network with thermal-responsive reversible linkages, which permit functionalities including targeted welding, magnetization reprogramming, and structural reconfiguration. These functions not only provide highly desirable structural and material programmability and reprogrammability but also enable the manufacturing of structures with complex geometry and magnetization distribution. The targeted welding is exploited for modular assembling of fundamental building modules with specific logics for complex actuation. The magnetization reprogramming enables altering the morphing mode of the manufactured structures. The shape reconfiguration under magnetic actuation is coupled with network plasticity to remotely transform two-dimensional tessellations into complex three-dimensional architectures, providing a new strategy of manufacturing functional soft architected materials such as three-dimensional kirigami. We anticipate that the reported magnetic dynamic polymer provides a new paradigm for the design and manufacturing of future multifunctional assemblies and reconfigurable morphing architectures and devices.
Adaptation to various scene configurations and object properties, stability and dexterity in robotic grasping manipulation is far from explored. This work presents an origami-based shape morphing fingertip design to actively tackle the grasping stability and dexterity problems. The proposed fingertip utilizes origami as its skeleton providing degrees of freedom at desired positions and motor-driven four-bar-linkages as its transmission components to achieve a compact size of the fingertip. 3 morphing types that are commonly observed and essential in robotic grasping are studied and validated with geometrical modeling. Experiments including grasping an object with convex point contact to pivot or do pinch grasping, grasped object reorientation, and enveloping grasping with concave fingertip surfaces are implemented to demonstrate the advantages of our fingertip compared to conventional parallel grippers. Multi-functionality on enhancing grasping stability and dexterity via active adaptation given different grasped objects and manipulation tasks are justified. Video is available at youtu.be/jJoJ3xnDdVk/.
The bistability of embedded elements provides a natural route through which to introduce reprogrammability to elastic meta-materials. However, attempts to leverage this programmability in objects that can change shape, or morph, have been limited by the tendency for the deformations induced by multiple elastic elements to be incompatible --- deformation is frustrated by geometry. We study the root cause of this frustration in a particular system, the soft morphable sheet, which is caused by an azimuthal buckling instability of bistable elements embedded within a sheet. With this understanding we show that, for this system at least, the root of frustration can itself be frustrated by an appropriate design of the lattice on which bistable elements are placed.
Flexible robotics are capable of achieving various functionalities by shape morphing, benefiting from their compliant bodies and reconfigurable structures. Here we construct and study a class of origami springs generalized from the known interleaved origami spring, as promising candidates for shape morphing in flexible robotics. These springs are found to exhibit nonlinear stretch-twist coupling and linear/nonlinear mechanical response in the compression/tension region, analyzed by the demonstrated continuum mechanics models, experiments, and finite element simulations. To improve the mechanical performance such as the damage resistance, we establish an origami rigidization method by adding additional creases to the spring system. Guided by the theoretical framework, we experimentally realize three types of flexible robotics -- origami spring ejectors, crawlers, and transformers. These robots show the desired functionality and outstanding mechanical performance. The proposed concept of origami-aided design is expected to pave the way to facilitate the diverse shape morphing of flexible robotics.
Active structures have the ability to change their shape, properties, and functionality as a response to changing operational conditions, which makes them more versatile than their static counterparts. However, most active structures currently lack the capability to achieve multiple, different target states with a single input actuation or require a tedious material programming step. Furthermore, the systematic design and fabrication of active structures is still a challenge as many structures are designed by hand in a trial and error process and thus are limited by engineers knowledge and experience. In this work, a computational design and fabrication framework is proposed to generate structures with multiple target states for one input actuation that dont require a separate training step. A material dithering scheme based on multi-material 3D printing is combined with locally applied copper coil heating elements and sequential heating patterns to control the thermo-mechanical properties of the structures and switch between the different deformation modes. A novel topology optimization approach based on power diagrams is used to encode the different target states in the structure while ensuring the fabricability of the structures and the compatibility with the drop-in heating elements. The versatility of the proposed framework is demonstrated for four different example structures from engineering and computer graphics. The numerical and experimental results show that the optimization framework can produce structures that show the desired motion, but experimental accuracy is limited by current fabrication methods. The generality of the proposed method makes it suitable for the development of structures for applications in many different fields from aerospace to robotics to animated fabrication in computer graphics.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
