Photo-Dissociable Fe3+-Carboxylate Coordination: A General Approach toward Hydrogels with Shape Programming and Active Morphing Functionalities

Shape programming of polymeric based electrothermal actuator (ETA) via artificially induced stress relaxation

Scientific Reports ◽

10.1038/s41598-019-47949-0 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Yu-Chen Sun ◽

Benjamin D. Leaker ◽

Ji Eun Lee ◽

Ryan Nam ◽

Hani E. Naguib

Keyword(s):

Stress Relaxation ◽

Electrothermal Actuator ◽

Induced Stress ◽

Shape Programming

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Shape Programming Using Triangular and Rectangular Soft Robot Primitives

Micromachines ◽

10.3390/mi10040236 ◽

2019 ◽

Vol 10 (4) ◽

pp. 236

Author(s):

Phone Khin ◽

Jin Low ◽

Marcelo Ang ◽

Chen-Hua Yeow

Keyword(s):

State Transition ◽

Position Control ◽

Angular Displacement ◽

Rotary Joint ◽

Different Types ◽

Shape Programming ◽

Mobility Unit ◽

Pneumatic Structures ◽

System Movement ◽

Position Control System

This paper presents fabric-based soft robotic modules with primitive morphologies, which are analogous to basic geometrical polygons—trilateral and quadrilateral. The two modules are the inflatable beam (IB) and fabric-based rotary actuator (FRA). The FRA module is designed with origami-inspired V-shaped pleats, which creates a trilateral outline. Upon pressurization, the pleats unfold, which enables propagation of angular displacement of the FRA module. This allows the FRA module to be implemented as a mobility unit in the larger assembly of pneumatic structures. In the following, we examine various ways by which FRA modules can be connected to IB modules. We studied how different ranges of motion can be achieved by varying the design of the rotary joint of the assemblies. Using a state transition-based position control system, movement of the assembled modules could be controlled by regulating the pneumatic pressurization of the FRA module at the joint. These basic modules allow us to build different types of pneumatic structures. In this paper, using IB and FRA modules of various dimensions, we constructed a soft robotic limb with an end effector, which can be attached to wheelchairs to provide assistive grasping functions for users with disabilities.

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Shape-programming of hyperelastic plates through differential growth: an analytical approach

Soft Matter ◽

10.1039/c9sm00160c ◽

2019 ◽

Vol 15 (11) ◽

pp. 2391-2399 ◽

Cited By ~ 3

Author(s):

Jiong Wang ◽

Qiongyu Wang ◽

Hui-Hui Dai ◽

Ping Du ◽

Danxian Chen

Keyword(s):

Plane Strain ◽

Analytical Approach ◽

Differential Growth ◽

Shape Programming ◽

Analytical Formulas

In this work, we study the plane-strain deformations of hyperelastic plates induced by differential growth, aiming to derive some analytical formulas for 2D shape-programming of hyperelastic plates.

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Deterministic Line-Shape Programming of Silicon Nanowires for Extremely Stretchable Springs and Electronics

Nano Letters ◽

10.1021/acs.nanolett.7b03658 ◽

2017 ◽

Vol 17 (12) ◽

pp. 7638-7646 ◽

Cited By ~ 20

Author(s):

Zhaoguo Xue ◽

Mei Sun ◽

Taige Dong ◽

Zhiqiang Tang ◽

Yaolong Zhao ◽

...

Keyword(s):

Silicon Nanowires ◽

Line Shape ◽

Shape Programming

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Cation-induced shape programming and morphing in protein-based hydrogels

Science Advances ◽

10.1126/sciadv.aba6112 ◽

2020 ◽

Vol 6 (18) ◽

pp. eaba6112

Author(s):

Luai R. Khoury ◽

Marina Slawinski ◽

Daniel R. Collison ◽

Ionel Popa

Keyword(s):

Serum Albumin ◽

Smart Materials ◽

Room Temperature ◽

Marked Change ◽

Innovative Strategy ◽

Innovative Method ◽

Ring Shape ◽

Shape Programming ◽

And Robotics ◽

Shape Changes

Smart materials that are capable of memorizing a temporary shape, and morph in response to a stimulus, have the potential to revolutionize medicine and robotics. Here, we introduce an innovative method to program protein hydrogels and to induce shape changes in aqueous solutions at room temperature. We demonstrate our approach using hydrogels made from serum albumin, the most abundant protein in the blood plasma, which are synthesized in a cylindrical or flower shape. These gels are then programmed into a spring or a ring shape, respectively. The programming is performed through a marked change in stiffness (of up to 17-fold), induced by adsorption of Zn2+ or Cu2+ cations. We show that these programmed biomaterials can then morph back into their original shape, as the cations diffuse outside the hydrogel material. The approach demonstrated here represents an innovative strategy to program protein-based hydrogels to behave as actuators.

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Amorphous Polymer Networks Combining Three Functionalities–Shape-memory, Biodegradability, and Drug Release

MRS Proceedings ◽

10.1557/proc-1190-nn11-34 ◽

2009 ◽

Vol 1190 ◽

Cited By ~ 3

Author(s):

Christian Wischke ◽

Axel Thomas Neffe ◽

Susi Steuer ◽

Andreas Lendlein

Keyword(s):

Drug Release ◽

Shape Memory ◽

Amorphous Polymer ◽

Polymer Networks ◽

Three Dimensional ◽

Hydrolytic Degradation ◽

Functional Materials ◽

Controlled Drug Release ◽

Diffusion Controlled ◽

Shape Programming

AbstractShape-memory polymers are of high scientific and technological interest in the biomedical field, e.g., as matrix for self-anchoring implantable devices. In this study, two different star-shaped copolyester tetroles, semi-crystalline oligo[(-caprolactone)-co-glycolide]tetrol (oCG) and amorphous oligo[(rac-lactide)-co-glycolide]tetrol (oLG), were synthesized and subsequently crosslinked by a low molecular weight diisocyanate resulting in copolyester urethane networks (N-CG, N-LG). Both networks could be loaded with model drugs and a diffusion controlled release of the drugs was observed without any effect on the mass loss as measure of hydrolytic degradation. However, the N-CG network’s capability of shape programming was disturbed as the crystallinity of the precursors got lost in the complex three dimensional architecture after crosslinking. By contrast, amorphous N-LG network showed an excellent shape-memory capability with a switching temperature around 36 °C corresponding to their glass transition temperature. This led to triple-functional materials combining biodegradability, shape-memory, and controlled drug release.

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Electro-thermo-mechanical behavior of carbon nanopaper shape memory polymer composites

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x211018848 ◽

2021 ◽

pp. 1045389X2110188

Author(s):

Veli Bugra Ozdemir ◽

Kawai Kwok

Keyword(s):

Mechanical Behavior ◽

Shape Memory ◽

Shape Change ◽

Shape Memory Polymer ◽

Axial Loading ◽

Element Model ◽

Close Correlation ◽

Stimuli Responsive ◽

Shape Memory Composites ◽

Shape Programming

An electro-active composite based on carbon nanopaper (CNP) shape memory polymer (SMP) composite is proposed for actuating deployment of composite deployable structures. Carbon nanopaper shape memory composites are stimuli-responsive materials that can change between programmed shapes and the original shape by a voltage input. The proposed composite is a sandwich structure where the CNP layer acts as a flexible electrical heater when a voltage difference is applied. The shape change behavior of CNP-SMP composite presents a coupled electrical-thermal-structural problem. This paper presents a combined experimental, numerical, and analytical study of the time-dependent shape programming, stowage, and actuation of the CNP-SMP composite. The governing equations for the multiphysics behavior are derived. Characterization of the electrical and mechanical properties of the materials are carried out and employed in a nonlinear, fully coupled electrical-thermal-structural finite element model. Shape programming, stowage and actuation characteristics of the composite are investigated experimentally under axial loading. An analytical model is derived for the thermo-mechanical behavior of the composite which directly expresses the recovery over time through the creep compliance function. Close correlation is obtained between experimental measurements and numerical simulations. The proposed model can accurately predict the load and shape characteristics throughout programming, stowage, and actuation.

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