Abstract:Functional elastomers with incredible toughness and stretchability are indispensable for applications in soft robotics and wearable electronics. Furthermore, coupled with excellent electrical and thermal properties, these materials are at the forefront of recent efforts toward widespread use in cutting-edge electronics and devices. Herein, we introduce a highly deformable eutectic-GaIn liquid metal alloy-embedded natural rubber (NR) architecture employing, for the first time, industrially viable solid-state mi… Show more
“…However, the FTIR spectrum (Figure 5b) AT‐PDMS did not show the characteristics of stretching bands of amine functionality. The reason could be due to the presence of a minimum of amine in AT‐PDMS [24] . Thus, the reaction of amines with epoxy groups of ENR could not be evident from FTIR; the only ring opening reaction of epoxy is apparent from the FTIR results.…”
Section: Resultsmentioning
confidence: 96%
“…Soft elastomeric materials have drawn significant attention because of their widespread applications in diverse fields, such as soft robotics, flexible and stretchable electronics, flexible sensors and actuators, soft coatings, and also in biology. [ 22–24 ] In most of the technological application of soft materials, generally very crude raw material like liquid PDMS or polyurethane is used. There are few commercially available natural and synthetic elastomers which have wide applications in tire and rubber industries.…”
Sulfur or peroxide crosslinking is the most common and conventional method to develop elastomeric materials. A new approach to crosslink epoxidized natural rubber (ENR) by aminopropyl terminated polydimethylsiloxane (AT‐PDMS) is described, intending to develop a new kind of hybrid organic–inorganic elastomers. The curing reaction is accelerated by using hydroquinone as a catalyst. The formation of the hybrid structure is evident from the appearance of two glass transition temperatures, at −1 and −120 °C, for the ENR and PDMS phases, respectively. The curing reaction is found to be of first order with respect to amine concentration with the estimated activation energy of ≈62 kJ mol−1. Comparing the mechanical properties to a typical ENR‐sulfur system leads to the conclusion that the ENR/AT‐PDMS hybrid structure is highly stretchable and soft, as demonstrated by its relatively higher strain at failure (up to ≈630%), and lower hardness and modulus values. The higher stretchability and soft nature of the material are achieved by introducing flexible PDMS chains during the curing process resulting to a hybrid elastomer networks. This kind of soft but robust materials can find several applications in diverse fields, such as soft robotics, flexible, and stretchable electronics.
“…However, the FTIR spectrum (Figure 5b) AT‐PDMS did not show the characteristics of stretching bands of amine functionality. The reason could be due to the presence of a minimum of amine in AT‐PDMS [24] . Thus, the reaction of amines with epoxy groups of ENR could not be evident from FTIR; the only ring opening reaction of epoxy is apparent from the FTIR results.…”
Section: Resultsmentioning
confidence: 96%
“…Soft elastomeric materials have drawn significant attention because of their widespread applications in diverse fields, such as soft robotics, flexible and stretchable electronics, flexible sensors and actuators, soft coatings, and also in biology. [ 22–24 ] In most of the technological application of soft materials, generally very crude raw material like liquid PDMS or polyurethane is used. There are few commercially available natural and synthetic elastomers which have wide applications in tire and rubber industries.…”
Sulfur or peroxide crosslinking is the most common and conventional method to develop elastomeric materials. A new approach to crosslink epoxidized natural rubber (ENR) by aminopropyl terminated polydimethylsiloxane (AT‐PDMS) is described, intending to develop a new kind of hybrid organic–inorganic elastomers. The curing reaction is accelerated by using hydroquinone as a catalyst. The formation of the hybrid structure is evident from the appearance of two glass transition temperatures, at −1 and −120 °C, for the ENR and PDMS phases, respectively. The curing reaction is found to be of first order with respect to amine concentration with the estimated activation energy of ≈62 kJ mol−1. Comparing the mechanical properties to a typical ENR‐sulfur system leads to the conclusion that the ENR/AT‐PDMS hybrid structure is highly stretchable and soft, as demonstrated by its relatively higher strain at failure (up to ≈630%), and lower hardness and modulus values. The higher stretchability and soft nature of the material are achieved by introducing flexible PDMS chains during the curing process resulting to a hybrid elastomer networks. This kind of soft but robust materials can find several applications in diverse fields, such as soft robotics, flexible, and stretchable electronics.
“…(C) Comparison of crack growth rate and tearing energy for natural rubber with 0 and 50 parts per hundred rubber (phr) LM. Reproduced with permission, 78 copyright 2021, American Chemical Society…”
Section: Structural Propertiesmentioning
confidence: 99%
“…In a recent study from Banerjee et al, 78 researchers were similarly looking to enhance the toughness of natural rubber polymer composites by embedding LM droplets. Although they were using a polymer composite already known for its tear resistance, the authors were able to integrate submicron LM droplets to increase the energy required to tear (tearing energy) by ×6 and reduce the crack growth rate by ×4 (Figure 5C).…”
Section: Structural Propertiesmentioning
confidence: 99%
“…Beyond simply existing as a soft and stretchable connection between electrical components, 163,164 LM polymer composites fit into the paradigm of this approaching reality as the materials with physical intelligence to bridge the gap between physical and digital environments to allow for a seamless transition. This is because of LMPC's inherent sensitivity to a wide range of stimuli, compatibility with biological systems, and durability under strenuous conditions 19,20,78,87 . Already, LM‐based devices are being designed to provide thermal and tactile sensation in virtual reality 165 .…”
Liquid metal polymer composites are an emerging class of functional materials with potentially transformative impacts in wearable electronics, soft robotics, and human-computer interactions. By employing different processing methods, room temperature liquid metal inclusions can be embedded in insulating polymers like elastomers to incorporate functional properties of metals while the matrix remains soft and stretchable. These solid-liquid composites offer an interesting, yet complex multifunctional material system. In this review, we present an exclusive overview of the synthesis methods, structural and functional properties, and applications of gallium-based liquid metal polymer composites. Common methods to control the size of liquid metal inclusions and their interaction in polymers are discussed. Moreover, the effect of liquid metal microstructures on the overall properties of the composites is summarized. We also highlight the new trends in terms of material composition, printing process, and novel applications of liquid metal polymer composites in intelligent systems.
Stimuli‐responsive mechano‐adaptive materials, capable of reversibly changing their mechanical properties when exposed to an external stimulus, are the next generation of smart materials with immense transformative potential for various technological applications. Although the concept of adaptive mechanical properties has been proven for some materials, it remains very challenging for soft elastomeric materials. The aim of this review is to provide new ideas and strategies for the development of mechano‐adaptive elastomeric composites using commercial rubber as the matrix polymer. The fundamental question addressed here is: How do the phase‐responsive functional fillers alter the mechanical properties? For a given physical network environment, what is the mechanism that gives rise to the stimuli‐responsive properties of the resulting composites?? This paper summarizes the preparation, structure and properties of recently developed mechano‐adaptive elastomeric materials. Furthermore, based on their structure‐property relationships, plausible applications of these smart materials in various technology‐specific applications such as soft robotics, actuators, sensors, smart tires, automotive design, aerospace etc. are demonstrated with representative examples. Finally, the paper critically discusses the existing challenges in the field of mechano‐adaptive elastomers in order to provide valuable insights in this area.This article is protected by copyright. All rights reserved.
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.
