Very recently, dynamic exchangeable covalent-bonding-based liquid crystal elastomer provided a new route for actuators with 3D shape mouldability and actuation capacity. [2,13,14] The dynamic transesterification reaction of these materials occurs at a temperature generally above 160 °C to allow shape molding, such as 3D flower and 3D wheel. [11] Meanwhile, Zhang et al. [10] prepared microchannel-programmed actuators through UV lithography template method. The film actuator is capable of reversibly changing its 3D shapes when exposed to acetone vapor. Despite brilliant advances, the manufacturing of those polymeric actuators typically involves high melt temperature, high pressure, hazardous chemical solvent or sophisticated machining equipment, which dramatically restricts the shaping of the actuators with complicated 3D structure. Furthermore, few soft actuators can maintain their inherent 3D structures when completely cut or damaged, and the entire devices have to be disposed. To conclude, a soft actuator with straightforward and eco-friendly shaping and reshaping processing condition and excellent self-healing ability is highly demanded.To address this issue, we present a biopolyester with hydrogen bonding and covalent bonding interpenetrating network, resulting in a mechanically robust, hygroscopic actuator that can arbitrarily shape and reshape the 3D geometric configuration at low ambient temperature (≤35 °C). Meanwhile, it exhibits excellent self-healing ability to maintain high performance of 3D structured actuators. Furthermore, specific 3D structures of the water-gradient-driven actuators are demonstrated to achieve different potential applications. The arbitrary shape deformations that copolyesters undergo at low temperature can inspire a new generation of synthetic soft actuators, which are in demand for actuating technologies, such as biomedical devices, flexible electronics, and soft robotics.To prepare the hygroscopic actuator with shaping and reshaping processability at low ambient temperature (≤35 °C), humidity-responsive macromolecular prepolymer with the melting point (T m = 23.48 °C) was first synthesized through the effective condensation copolymerization reaction of crystalline poly(ethylene glycol) (PEG) and poly(tetramethylene glycol) (PTMG) precursor ( 1 H NMR, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC) analysis Soft materials that can reversibly transform shape in response to moisture have applications in diverse areas such as soft robotics and biomedicine. However, the design of a structurally transformable or mechanically selfhealing version of such a humidity-responsive material, which can arbitrarily change shape and reconfigure its 3D structures remains challenging. Here, by drawing inspiration from a covalent-noncovalent network, an elaborately designed biopolyester is developed that features a simple hygroscopic actuation mechanism, straightforward manufacturability at low ambient temperature (≤35 °C), fast and stable response, robust mechanica...
It is a challenge to manufacture flexible sensors that possess easily distinguishable biomotion signals, strong response reliability, and excellent self-healing capability. Herein, a self-healing sensor with tunable positive/ negative piezoresistivity is designed by the construction of hierarchical structure connected through supramolecular metal-ligand coordination bonds. The developed sensors can be integrated with the human body to detect multiple tiny signals, such as pronunciation, coughing, and deep breathing. Interestingly, the nanostructured elastomer sensor with and without a flexible yarn electrode shows negative and positive current signals, respectively, making it easy to be identify. Furthermore, it exhibits very fast (2 min), autonomous, and repeatable self-healing ability with high-healing efficiency (88.6% after the third healing process). The healed samples still possess flexibility, high sensitivity, and accurate detection capability, even after bending over 10 000 cycles. The excellent biomimetic self-healing performance combined with the tunable piezoresistivity make it promising for next-generation wearable electronics.
The polyurethane-vitrimers with the properties of reprocessing, thermally-induced dual-shape memory effect and self-welding would reduce waste and accumulated pollution of crosslinking polymer.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.