scholarly journals Encoding kirigami bi-materials to morph on target in response to temperature

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Lu Liu ◽  
Chuan Qiao ◽  
Haichao An ◽  
Damiano Pasini
Keyword(s):  
Chemical Cues ◽  
Environmental Stimulus ◽  
Active Materials ◽  
Responsive Materials ◽  
Shape Morphing ◽  
Material Chemistry ◽  
Shape Match ◽  
Temperature Stimulus ◽  
Response To Temperature ◽  
Shape Changes

AbstractShape morphing in response to an environmental stimulus, such as temperature, light, and chemical cues, is currently pursued in synthetic analogs for manifold applications in engineering, architecture, and beyond. Existing strategies mostly resort to active, namely smart or field responsive, materials, which undergo a change of their physical properties when subjected to an external stimulus. Their ability for shape morphing is intrinsic to the atomic/molecular structure as well as the mechanochemical interactions of their constituents. Programming shape changes with active materials require manipulation of their composition through chemical synthesis. Here, we demonstrate that a pair of off-the-shelf passive solids, such as wood and silicone rubber, can be topologically arranged in a kirigami bi-material to shape-morph on target in response to a temperature stimulus. A coherent framework is introduced to enable the optimal orchestration of bi-material units that can engage temperature to collectively deploy into a geometrically rich set of periodic and aperiodic shapes that can shape-match a predefined target. The results highlight reversible morphing by mechanics and geometry, thus contributing to relax the dependence of current strategies on material chemistry and fabrication.

scholarly journals Covalent organic framework nanofluidic membrane as a platform for highly sensitive bionic thermosensation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pengcheng Zhang ◽  
Sifan Chen ◽  
Changjia Zhu ◽  
Linxiao Hou ◽  
Weipeng Xian ◽  
...  
Keyword(s):  
Thermal Sensation ◽  
Biological Response ◽  
Covalent Organic Framework ◽  
Physiological Processes ◽  
Potential Applicability ◽  
Continuous Potential ◽  
Temperature Stimulus ◽  
Nanofluidic System ◽  
Response To Temperature ◽  
Organic Framework

AbstractThermal sensation, which is the conversion of a temperature stimulus into a biological response, is the basis of the fundamental physiological processes that occur ubiquitously in all organisms from bacteria to mammals. Significant efforts have been devoted to fabricating artificial membranes that can mimic the delicate functions of nature; however, the design of a bionic thermometer remains in its infancy. Herein, we report a nanofluidic membrane based on an ionic covalent organic framework (COF) that is capable of intelligently monitoring temperature variations and expressing it in the form of continuous potential differences. The high density of the charged sites present in the sub-nanochannels renders superior permselectivity to the resulting nanofluidic system, leading to a high thermosensation sensitivity of 1.27 mV K−1, thereby outperforming any known natural system. The potential applicability of the developed system is illustrated by its excellent tolerance toward a broad range of salt concentrations, wide working temperatures, synchronous response to temperature stimulation, and long-term ultrastability. Therefore, our study pioneers a way to explore COFs for mimicking the sophisticated signaling system observed in the nature.

scholarly journals Shape-morphing carbon fiber composite using electrochemical actuation

2020 ◽  
Vol 117 (14) ◽  
pp. 7658-7664 ◽  
Author(s):  
Wilhelm Johannisson ◽  
Ross Harnden ◽  
Dan Zenkert ◽  
Göran Lindbergh
Keyword(s):  
Solid State ◽  
Carbon Fibers ◽  
Fiber Composite ◽  
Lithium Ion ◽  
Proof Of Concept ◽  
Carbon Fiber Composite ◽  
Shape Morphing ◽  
Commercial Carbon ◽  
Structural Battery ◽  
Shape Changes

Structures that are capable of changing shape can increase efficiency in many applications, but are often heavy and maintenance intensive. To reduce the mass and mechanical complexity solid-state morphing materials are desirable but are typically nonstructural and problematic to control. Here we present an electrically controlled solid-state morphing composite material that is lightweight and has a stiffness higher than aluminum. It is capable of producing large deformations and holding them with no additional power, albeit at low rates. The material is manufactured from commercial carbon fibers and a structural battery electrolyte, and uses lithium-ion insertion to produce shape changes at low voltages. A proof-of-concept material in a cantilever setup is used to show morphing, and analytical modeling shows good correlation with experimental observations. The concept presented shows considerable promise and paves the way for stiff, solid-state morphing materials.

Robotic surfaces with reversible, spatiotemporal control for shape morphing and object manipulation

2021 ◽  
Vol 6 (53) ◽  
pp. eabf5116
Author(s):  
Ke Liu ◽  
Felix Hacker ◽  
Chiara Daraio
Keyword(s):  
Stimuli Responsive ◽  
Mechanical Stiffness ◽  
Responsive Materials ◽  
Shape Morphing ◽  
Deformation Response ◽  
Control Scheme ◽  
Out Of Plane ◽  
Passive Network ◽  
Liquid Crystal Elastomers ◽  
Layered Design

Continuous and controlled shape morphing is essential for soft machines to conform, grasp, and move while interacting safely with their surroundings. Shape morphing can be achieved with two-dimensional (2D) sheets that reconfigure into target 3D geometries, for example, using stimuli-responsive materials. However, most existing solutions lack the ability to reprogram their shape, face limitations on attainable geometries, or have insufficient mechanical stiffness to manipulate objects. Here, we develop a soft, robotic surface that allows for large, reprogrammable, and pliable shape morphing into smooth 3D geometries. The robotic surface consists of a layered design composed of two active networks serving as artificial muscles, one passive network serving as a skeleton, and cover scales serving as an artificial skin. The active network consists of a grid of strips made of heat-responsive liquid crystal elastomers (LCEs) containing stretchable heating coils. The magnitude and speed of contraction of the LCEs can be controlled by varying the input electric currents. The 1D contraction of the LCE strips activates in-plane and out-of-plane deformations; these deformations are both necessary to transform a flat surface into arbitrary 3D geometries. We characterize the fundamental deformation response of the layers and derive a control scheme for actuation. We demonstrate that the robotic surface provides sufficient mechanical stiffness and stability to manipulate other objects. This approach has potential to address the needs of a range of applications beyond shape changes, such as human-robot interactions and reconfigurable electronics.

Computational Design of Active Lattice Structures for 4D Printed Pneumatic Shape Morphing

2019 ◽  
Author(s):  
Cosima du Pasquier ◽  
Pascal Koller ◽  
Tino Stankovic ◽  
Kristina Shea
Keyword(s):  
Complex Shape ◽  
Lattice Structure ◽  
Design Method ◽  
Shape Change ◽  
Computational Design ◽  
Digital Fabrication ◽  
Computational Effort ◽  
Shape Morphing ◽  
Actuator Placement ◽  
Shape Changes

Abstract With advances in 3D printing and digital fabrication an opportunity is presented to realize highly customized designs whose shape can change and adapt to facilitate their functionality. A computational design method to determine the configuration of 2D pneumatic shape morphing lattices using a direct search method is implemented and assessed. The method is tested using a Kagome unit cell lattice structure, which is particularly well suited for shape morphing. To achieve shape change, beams are replaced by linear actuators such as those found in pneumatic 4D printing, whose number and placement are optimized to replicate a given target shape. The actuator placement and deformation accuracy are given for four main curvature changes: linear, convex, concave and the transition from one to the other. The results are assessed in terms accuracy of deformation and computational effort. It is shown that the method proposed produces structures that can replicate complex shape changes within 1% of the desired shape. Reducing the number of actuators for robustness purposes is shown to affect the results minimally.

scholarly journals Reconfigurable and programmable origami dielectric elastomer actuators with 3D shape morphing and emissive architectures

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiangxin Wang ◽  
Shaohui Li ◽  
Dace Gao ◽  
Jiaqing Xiong ◽  
Pooi See Lee
Keyword(s):  
Light Emission ◽  
Dielectric Elastomer ◽  
Electronic Systems ◽  
Shape Morphing ◽  
Dielectric Elastomer Actuators ◽  
New Strategy ◽  
3D Shape Morphing ◽  
Soft Actuators ◽  
Local Stiffness ◽  
Shape Changes

AbstractSoft actuators with the capability to generate programmable and reconfigurable motions without the use of complicated and rigid infrastructures are of great interest for the development of smart, interactive, and adaptive soft electronic systems. Here, we report a new strategy to achieve a transparent and reconfigurable actuator by using a dielectric elastomer actuator (DEA), which provides mechanical strains under electrical bias, integrated with origami ethyl cellulose (EC) paper that “instructs” the shape changes of the actuator. The actuator can be reconfigured and multiple mechanical motions can be programmed in the device by creating crease patterns that induce variations in the local stiffness to direct the actuations. With the versatile design and fabrication approach, a light emission device with dynamic shape changes was demonstrated.

The Load Capacity of a Kagome Based High Authority Shape Morphing Structure

2004 ◽  
Vol 73 (1) ◽  
pp. 128-133 ◽  
Author(s):  
S. L. dos Santos e Lucato ◽  
A. G. Evans
Keyword(s):  
Load Capacity ◽  
Failure Mechanisms ◽  
Additional Constraint ◽  
Numerical Examples ◽  
Shape Morphing ◽  
Truss Core ◽  
Morphing Structure ◽  
The Individual ◽  
External Loads ◽  
Shape Changes

A protocol for optimizing a high authority shape morphing plate is described. The design incorporates an active Kagome back-plane capable of changing the shape of a solid face by transmitting loads through a tetrahedral truss core. The optimization assesses the required geometric dimensions and actuator specifications in order to maximize the permissible shape changes and load capacity. The critical external loads for all failure mechanisms of the individual components are calculated and used as constraints in the optimization. Resistance of the structure to actuation is presented as an additional constraint. The ensuing relations are subsequently used to choose the best material for a given application. Numerical examples of the procedure are given for a defined structure.

Tensegrity Structures Incorporating Actuator and Pseudoelastic Shape Memory Alloys

2020 ◽  
Author(s):  
Gavin M. Butler ◽  
Edwin A. Peraza Hernandez
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Large Deformations ◽  
External Disturbances ◽  
Active Materials ◽  
Tensegrity Structures ◽  
Shape Morphing ◽  
New Class ◽  
Potential Applications ◽  
Accumulated Error

Abstract Tensegrity structures are networks of tensile and compressive truss members that have pre-stressability and shape-morphing capabilities. Potential applications of tensegrities in the aerospace, civil, and robotics fields require them to have actuation capabilities and adjustable stiffness. An approach to infuse these properties into tensegrities is to employ active materials. Shape memory alloys (SMAs) are active materials with the ability of exchanging mechanical and thermal energies. They have actuation capabilities enabled by the shape memory effect and large recoverable deformations enabled by the pseudoelastic effect. This paper presents a study on the integration of actuator and pseudoelastic SMAs into tensegrities to create a new class of stifftruss structures that exhibit controlled large deformations. A model for tensegrities that incorporates mechanical equilibrium, thermal equilibrium, and an SMA constitutive model is first developed. The tensile members in the tensegrities may be comprised of actuator or pseudoelastic SMA wires. The actuator wires can be manipulated through Joule heating to change the shape of the tensegrity structure on demand. The pseudoelastic wires provide high stiffness under moderate external disturbances, and become compliant and allow for large deformations as their stress is increased by the actuator wires. This unique combination of actuator and pseudoelastic SMA members in tensegrities is demonstrated through examples of controlled morphing of a tensegrity beam and a tensegrity plate. The results show that using pseudoelastic members antagonistic to the actuators, as opposed to elastic members, reduces the accumulated error and the energy required to control the tensegrities.

Multi-Functional 3D Curvilinear Self-Folding of Glassy Polymers

2020 ◽  
Author(s):  
Jae Gyeong Lee ◽  
Sukyoung Won ◽  
Jeong Eun Park ◽  
Jeong Jae Wie
Keyword(s):  
Light Absorption ◽  
Three Dimensional ◽  
Strain Engineering ◽  
Local Deformation ◽  
Glassy Polymers ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Shape Morphing ◽  
Curvilinear Structures ◽  
External Stimuli

Abstract The selective light absorption of pre-stretched thermoplastic polymeric films enables wireless photothermal shape morphing from two-dimensional Euclidean geometry of films to three-dimensional (3D) curvilinear architectures. For a facile origami-inspired programming of 3D folding, black inks are printed on glassy polymers that are used as hinges to generate light-absorption patterns. However, the deformation of unpatterned areas and/or stress convolution of patterned areas hinder the creation of accurate curvilinear structures. In addition, black inks remain in the film, prohibiting the construction of transparent 3D architectures. In this study, we demonstrate the facile preparation of transparent 3D curvilinear structures with the selection of the curvature sign and chirality via the selective light absorption of detachable tapes. The sequential removal of adhesive patterns allowed sequential folding and the control of strain responsivity in a single transparent architecture. The introduction of multiple heterogeneous non-responsive materials increased the complexity of strain engineering and functionality. External stimuli responsive kirigami-based bridge triggered the multi-material frame to build the Gaussian curvature. Conductive material casted on the film in a pattern retained the conductivity, despite local deformation. This type of tape patterning system, adopting various materials, can achieve multifunction including transparency and conductivity.

Molecular dynamics simulations and PRISM theory study of solutions of nanoparticles and triblock copolymers with solvophobic end blocks

2018 ◽  
Vol 3 (3) ◽  
pp. 453-472 ◽  
Author(s):  
Daniel J. Beltran-Villegas ◽  
Ivan Lyubimov ◽  
Arthi Jayaraman
Keyword(s):  
Molecular Dynamics ◽  
Phase Behavior ◽  
Triblock Copolymers ◽  
Inorganic Nanoparticles ◽  
Amphiphilic Block Copolymers ◽  
Active Materials ◽  
Rich Phase ◽  
Responsive Materials ◽  
The Rich ◽  
Dynamics Simulations

Hybrid materials composed of inorganic nanoparticles (NPs) and amphiphilic block copolymers (BCPs) combine desirable properties of NPs with the rich phase behavior of BCPs, making them attractive for use in biomaterials, responsive materials for sensing, active materials in robotics, etc.

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