A Study of Mechanoelectrical Transduction Behavior in Polyvinyl Chloride (PVC) Gel as Smart Sensors

Polyvinyl chloride (PVC) gels are soft electroactive polymers being researched for soft robotic applications. Sensing properties of these electroactive polymers have not been investigated in detail in regard to fundamental mechanoelectrical transduction behavior, but this smart material has been shown to exhibit a detectable response to external stimuli. This study shows PVC gels to be an extremely sensitive material when undergoing mechanoelectrical transduction and explores some response dependencies and proposes a theoretical framework for mechanoelectrical transduction within the gel. The work presented here also uncovers a very interesting phenomena under extremely low compressive loads during the initial contact with the gel. This phenomenon is attributed to a surface tension creeping motion onto the loading surface with an accompanying polarity inversion in the sensing signal relative to fully loaded gels in compression. Experimental work on hysteresis was also completed showing very little memory in steady state mechanoelectrical response to repeated stepped loading cycles. This study demonstrates the mechanoelectric ability of PVC gels to perform in sensing experiments and acts as a fundamental framework to further broaden the applications of PVC gel sensors.

Recent Progress on Electroactive Polymers: Synthesis, Properties and Applications

Electroactive polymers (EAPs) are an advanced family of polymers that change their shape through electric stimulation and have been a point of interest since their inception. This unique functionality has helped EAPs to contribute to versatile fields, such as electrical, biomedical, and robotics, to name a few. Ionic EAPs have a significant advantage over electronic EAPs. For example, Ionic EAPs require a lower voltage to activate than electronic EAPs. On the other hand, electronic EAPs could generate a relatively larger actuation force. Therefore, efforts have been focused on improving both kinds to achieve superior properties. In this review, the synthesis routes of different EAP-based actuators and their properties are discussed. Moreover, their mechanical interactions have been investigated from a tribological perspective as all these EAPs undergo surface interactions. Such interactions could reduce their useful life and need significant research attention for enhancing their life. Recent advancements and numerous applications of EAPs in various sectors are also discussed in this review.

Modeling of Dielectric Electroactive Polymer Actuators with Elliptical Shapes

Dielectric electroactive polymers have been widely used in recent applications based on smart materials. The many advantages of dielectric membranes, such as softness and responsiveness to electric stimuli, have lead to their application in actuators. Recently, researchers have aimed to improve the design of dielectric electroactive polymer actuators. The modifications of DEAP actuators are designed to change the bias mechanism, such as spring, pneumatic, and additional mass, or to provide a double cone configuration. In this work, the modification of the shape of the actuator was analyzed. In the standard approach, a circular shape is often used, while this research uses an elliptical shape for the actuator. In this study, it was shown that this construction allows a wider range of movement. The paper describes a new design of the device and its model. Further, the device is verified by the measurements.

Electroactive Polymers Obtained by Conventional and Non-Conventional Technologies

Electroactive polymers (EAPs), materials that present size/shape alteration in response to an electrical stimulus, are currently being explored regarding advanced smart devices, namely robotics, valves, soft actuators, artificial muscles, and electromechanical sensors. They are generally prepared through conventional techniques (e.g., solvent casting and free-radical polymerization). However, non-conventional processes such as those included in additive manufacturing (AM) are emerging as a novel approach to tune and enhance the electromechanical properties of EAPs to expand the scope of areas for this class of electro-responsive material. This review aims to summarize the published work (from the last five years) in developing EAPs either by conventional or non-conventional polymer processing approaches. The technology behind each processing technique is discussed as well as the main mechanism behind the electromechanical response. The most common polymer-based materials used in the design of current EAPs are reviewed. Therefore, the main conclusions and future trends regarding EAPs obtained by conventional and non-conventional technologies are also given.

Biopolymers and its application as electroactive polymers

Smart materials are a group of materials that exhibit the ability to change their composition or structure, their electrical and/or mechanical properties, or even their functions in response to an external stimulus such as heat, light, electricity, pressure, etc. Some of the advantages of these materials are: lightweight, flexibility, low cost of production, high energy density, fast response and compact size. One of the promises in the area of smart materials can be found in “smart polymer”. Polymers have many attractive characteristics, such as: lightweight, inexpensiveness, fractures tolerant, and pliable. Furthermore, they can be configured into almost any conceivable shape and their properties can be tailored according to the required needs. The capability of electroactive polymers (EAPs) to respond to electrical stimuli with a mechanical response, is attracting the attention of the scientific community from a wide range of disciplines. Biopolymers in recent decades have been studied as potential electroactive materials. These groups of polymers are extracted from a natural source; thus, they are eco-friendly, additionally they stand as a cheaper solution for the development of smart materials.The present manuscript will explore some of its applications as EAPs.