Electroactive Polymer Research Articles

Poly(aniline-2-sulfonic acid-co-aniline) modified nickel-doped carbon catalyst for power generation in microbial fuel cells

Microbial fuel cells (MFCs) are self-powered devices used for power generation. However, the advancement of the technology is hindered poor durability, sluggish electrochemical reaction kinetics, and high capital costs, especially for cathode materials. In this study, we developed a nickel (Ni) chelate catalyst derived from thiourea-formaldehyde resins (Ni-TF), which incorporates sulphur (S) and nitrogen (N) groups, to enhance the oxygen reduction reaction (ORR) kinetics. To improve the electrical conductivity and electron transfer and to investigate the influence of N and S content, Ni-TF particles were interwoven with polyaniline and aniline-2-sulfonic acid-co-aniline, respectively. The integration of self-doped electroactive polymer with Ni-TF significantly enhanced the catalytic activity of the resulting composite (SPAN-PAN/Ni-SNC). SPAN-PAN/Ni-SNC exhibited a high oxygen reduction potential of 0.335 V (vs. RHE) at −0.018 mA, superior stability, and a low charge transfer resistance of 95.1 Ω. Furthermore, SPAN-PAN/Ni-SNC recorded a maximum power density of 2045.1 mW m−2 at a current density of 8343.8 mA m−2, compared to 873.67 mW m−2 and 5453.6 mA m−2 for Ni-SNC. This improvement is attributed to the synergy between the interwoven Ni-SNC and conducting copolymer. These findings indicate that encapsulating metal-doped catalysts within heteroatom-doped carbons can enhance long-term fuel cell performance and related applications.

Ethylendiaminetetrakis(1,10-phenanthroline)dicopper(II) chlorided: Synthesis and application for voltammetric determination of doxycycline in real samples

The study describes on the preparation of a new homobinuclear mixed ligand complex µ-ethylendiaminetetrakis(1,10-phenanthroline)dicopper(II) chloridedihydrate (EP4Cu2CH2) from a previously reported complex chlorobis(1,10-phenanthroline)copper(II) chloridemonohydrate (CP2CuCH). The synthesis was checked by spectroscopy (UV–Vis, FT IR), CHN elemental analysis, Cu determination using ICP-OES, electrolytic conductivity, qualitative and quantitative chloride estimation, and melting point measurements. The new complex was applied for the modification of a glassy carbon electrode (poly(EP4Cu2CH2)/GCE) for determination of doxycycline (Doxy), (which belongs to a tetracycline antibiotic, mainly used for the treatment of a wide bacterial infections) by selective, accurate, and precise differential pulse voltammetric method. Electrode characterization revealed modification of the electrode surface by a conductive, and electroactive polymer film (poly(EP4Cu2CH2)/GCE) leading to improved effective electrode surface area. In contrast to the bare electrode, the appearance of two well-resolved irreversible oxidative peaks at much reduced potential with sevenfold current enhancement at poly(EP4Cu2CH2)/GCE showed the catalytic effect of the modifier towards Doxy. Differential pulse voltammetric current response of poly(EP4Cu2CH2)/GCE showed a linear dependence on the concentration of Doxy in the range 5 × 10−8 – 3.5 × 10−4 M with a detection limit of 3.5 × 10−9. The Doxy levels in four tablet brands were in the range 96.00–101.30 % of their labeled values. Spike recovery results in tablet, cow milk, and human urine samples were 98.90–100.73 %, 98.30–100.00 %, and 98.50–100.54 %, respectively. Based on the innovative mixed ligand poly(EP4Cu2CH2)/GCE, the interference recovery results about 4.79 % error, lesser LoD, and a broader concentrationrange than most previously published methods validated the present method’s potential applicability with excellent accuracy and sensitivity for Doxy determination in various real samples with complex matrix.

Multidimensional analysis of textiles coated with electroactive polymers for actuators

This paper presents a multidimensional analysis of textiles coated with conductive polymers for actuators. The purpose of using multidimensional scaling analysis is to compare similarities and dissimilarities between conductive textiles obtained through conductive polymeric film deposition to observe the optimal value for electrical resistance and to select an adequate method to achieve conductive fabric using different polymers (polyethylene glycol, polyvinyl alcohol or polyvinylidene fluoride) and metal microparticles (copper or nickel). The multidimensional analysis is based on mapping a series of material properties from a proximity matrix (similarities or dissimilarities) between these properties. Multidimensional scaling allows rebuilding the exact map of the values (within approximately a symmetry or rotation). To fit dissimilarity or similarity matrices for multiple variables into one common space estimating the weight parameters for each variable, the INDSCAL model (individual differences multidimensional scaling) was used.

Thin-film electrodes of dielectric elastomer-based actuators for an active vibration control system

Precision research and technological equipment, as a rule, is not able to provide its specification characteristics without a high-quality vibration protection system. Active vibration control of an object is provided with the help of an additional source of movement, an actuator. The most promising high accuracy actuators are based on smart materials, such as materials with shape memory, piezoelectric and magnetostrictive materials, electro- and magnetic active fluids and elastomers. Dielectric elastomer is one of the types of electroactive polymers. Actuators based on a dielectric elastomer show high performance in terms of accuracy and speed and operate due to the controllable deformation of the elastomer under the action of a high voltage electric field. The paper provides a comparison of actuators based on sheet and thin film control electrodes. The influence of the quality of the polymer surface and the type of electrodes on the travel range of the actuator and maximum amplitude of vibrations the system can suppress on the basis of a dielectric elastomer is estimated. The formation of the electrode by magnetron sputtering in vacuum makes it possible to create a thin-film layer of copper that covers the elastomer, despite the developed surface. The effect of ion treatment of an elastomer before coating on the quality of the formed electrode is considered. After the ion treatment, the surface of the elastomer acquires a more uniform regular structure. A thin-film electrode layer is formed according to the topology of the elastomer to an accomplished standard.

Electrochemical DNA Sensor Based on Poly(proflavine) Deposited from Natural Deep Eutectic Solvents for DNA Damage Detection and Antioxidant Influence Assessment

Electrochemical DNA sensors for DNA damage detection based on electroactive polymer poly(proflavine) (PPFL) that was synthesized at screen-printed carbon electrodes (SPCEs) from phosphate buffer (PB) and two natural deep eutectic solvents (NADESs) consisting of citric or malonic acids, D-glucose, and a certain amount of water (NADES1 and NADES2) were developed. Poly(proflavine) coatings obtained from the presented media (PPFLPB, PPFLNADES1, and PPFLNADES2) were electrochemically polymerized via the multiple cycling of the potential or potentiostatic accumulation and used for the discrimination of thermal and oxidative DNA damage. The electrochemical characteristics of the poly(proflavine) coatings and their morphology were assessed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The working conditions for calf thymus DNA implementation and DNA damage detection were estimated for all types of poly(proflavine) coatings. The voltammetric approach made it possible to distinguish native and chemically oxidized DNA while the impedimetric approach allowed for the successful recognition of native, thermally denatured, and chemically oxidized DNA through changes in the charge transfer resistance. The influence of different concentrations of conventional antioxidants and pharmaceutical preparations on oxidative DNA damage was characterized.

“Click”able monomer and polymers based on Azide-functionalized 3,4-Propylenedioxythiophene with tunable processibility

This research introduces 3,3-bis(azidomethyl)-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine (ProDOT-AM2) as a versatile building block monomer for the synthesis of variously functionalized monomers and copolymers via “click”able 1,3-dipolar cycloaddition. The efficiency of this building block as a precursor to a wide range of ProDOT-based monomers is demonstrated by click reaction with various alkynes. The 1,3-dipolar cycloaddition of ProDOT-AM2 with different alkynes in the presence of a catalyst yields a novel class of ProDOT derivatives via a “triazole-locker” mechanism. Depending on the bases utilized, two distinct types of functionalized monomers, namely bistriazole and triazole, are obtained. The resulting polymers from the oxidative polymerization of selected monomers exhibit high solution processability and stability under multiple chemical redox processes, demonstrating potential applications in chemical chromics. Additionally, a conjugated copolymer containing ProDOT-AM2 is synthesized via Stille reaction conditions and subsequently post-functionalized with alkynes via a “triazole-locker” mechanism. Characterization studies via IR and 1H NMR confirm the successful post-functionalization of the polymer. Electropolymerization of ProDOT-AM2 yields an electroactive polymer (PProDOT-AM2), indicating its potential utility in conducting polymers to be further post-functionalized. Overall, this methodology presents a straightforward approach for synthesizing a new class of monomers for conducting polymers and polymer modification using click chemistry.

Slot‐Die‐Printed Electroactive Polymer Actuators with High‐Strain Sensitivity for Soft Robotic Applications

AbstractIonic electroactive polymer gels are widely employed as actuators in soft robotics due to their ability to undergo rapid mechanical deformation under low‐voltage. How to improve the performance of the ionic electroactive polymer actuators is always the focus of research in this field. Optimizing the migration of ions within the actuator is crucial for enhancing the actuation performance. In this regard, this study innovatively introduces slot‐die‐printing technology to fabricate gel actuation layers characterized by high smoothness and uniform particle distribution, achieving seamless integration between the electrodes and gel actuation layers, while mitigating issues associated with ion accumulation due to polymer clustering. Furthermore, this study attempts to add lactic acid to the traditional CS‐PVA‐IL gel, effectively strengthening the connection between CS and PVA, and promoting smooth ion transport within the gel. The results demonstrate that the actuators prepared in this study achieved a high‐bending‐strain of 0.35%, with a retention rate of 91% for actuation displacement after 10 000 cycles, showcasing superior actuation performance compared to existing research. The fabrication method proposed in this study is simple and highly reproducible, making it suitable for widespread industrial application, and providing a new approach for future industrial production of soft robotics.

Structuring of electrorheological fluids in polymer matrices for miniature actuators

Miniature actuators are utilized in various application fields, from robotics to medical devices, where compact dimensions, precise movements, and cost-effectiveness are crucial factors. Particularly for applications like braille displays, there is a critical demand for lightweight, portable, and affordable actuators to integrate into daily life for visually impaired people. However, existing actuation technologies such as electroactive polymers, electrorheological materials, and piezoelectric elements often do not meet the specific requirements of miniature actuators, especially for braille displays. Therefore, this study investigates the behavior of electrorheological fluids incorporated into polymer matrices of cellulose and proteins for miniature actuators to overcome the primary challenge of sedimentation through the structuring of the liquid. The gel formulations are tested in three distinct setups: the V-shaped, horizontal plates, and valve system. These experiments demonstrated immediate structural changes in the gel formulations, achieving reversible movement. Furthermore, the valve setup even enabled the analysis of the strength of the hardened mixtures by the resistance against applied air pressure. The results demonstrate that incorporating electrorheological fluids into polymer matrices is not only feasible but also preserves the characteristic behavior of electrorheological fluids under electrical field exposure. This behavior validates the applicability and suitability of modified electrorheological fluid mixtures in miniature actuators.

Corrosion protection performance of poly(PyM-co-GMA)/SWCNT nanocomposites coating on mild steel

Recently, there has been significant emphasis on developing electroactive functional methacrylate polymers for anticorrosive applications. In this context, we have synthesized Poly[(3,5-dimethyl-1H-pyrazole-1-yl) methyl methacrylate-co-glycidyl methacrylate] [Poly(PyM-co-GMA)] and its nanocomposite with single- walled carbon nanotubes (SWCNTs) [Poly(PyM-co-GMA)/SWCNT]. The resulting materials were characterized using Fourier Transform Infrared spectroscopy (FT-IR) and X-ray Diffraction analysis (XRD). Morphological changes due to the incorporation of SWCNTs were examined using field-emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM). The optical properties of Poly(PyM-co-GMA) and Poly(PyM-co-GMA)/SWCNT (0.5, 1.0, and 1.5 wt. %) were investigated. The thermal behavior of Poly(PyM-co-GMA) and its SWCNT nanocomposites was analyzed through thermogravimetric analysis (TGA). The anticorrosive performance of the prepared materials was evaluated on a mild steel substrate (MS) in a 3.5% (w/v) NaCl medium using electrochemical techniques. Results from potentiodynamic polarization and electrochemical impedance spectroscopy indicate that the Poly(PyM-co-GMA) and Poly(PyM- co-GMA)/SWCNT coatings (0.5, 1.0, and 1.5 wt. %) provide effective barrier protection for mild steel against marine environments.

Realizing Ultrahigh Cycle Life Anode for Sodium-Ion Batteries through Heterostructure Design and Introducing Electro Active Polymer Coating.

Bi2S3 has attracted increasing attention in sodium-ion batteries (SIBs) for its high theoretical capacity and low discharge platform. However, the sodium storage performance of Bi2S3 is limited by poor electrical conductivity and volume expansion during cycling. Herein, we report a special polypyrrole (PPy)-coated MoS2/Bi2S3 (MBS@PPy) heterostructure composite obtained by hydrothermal reaction as an anode material for SIB. As a result, the MBS@PPy composites demonstrate exceptional electrochemical performance in SIB, exhibiting a high capacity of 361.1 mA h g-1 at 10 A g-1 and showcasing remarkable rate performance. Even under a high current density of 35 A g-1, the specific capacity remains stable at 280 mA h g-1 after 2,000 cycles. Furthermore, a successfully assembled Na3V2(PO4)3//MBS@PPy sodium-ion full cell can achieve an impressive specific capacity of approximately 400 mA h g-1 after 300 cycles at 0.5 A g-1. In MBS@PPy composites, the polypyridine coating not only improves the interfacial conductivity of nanorods but also effectively inhibits the agglomeration between nanorods due to large volume changes. The MoS2 heterostructure further inhibits the coarsening of the internal structure, improves electron transport and reaction kinetics, and increases the rate capability of the material. This work provides an effective strategy to develop energy storage materials with superior electrochemical properties.

Microwave, ferroelectric and electromechanical studies of free standing blended electroactive polymer films

This study probes the enhancement of the microwave, ferroelectric and electromechanical properties of electroactive polymer (EAP) blended films made out of P(VDF-TrFE) and Nafion. Blended films are synthesized using the solution casting method, with different Nafion volume percentage (0 % to 30 %), and the phase formation is confirmed using XRD and FTIR spectroscopy. The morphological features are studied using FESEM. The reflection loss of the blended films as a function of thickness has been studied in both X and Ku band using a VNA. The contribution of reflection and absorption to the shielding effectiveness are also explored. 10 % Nafion inclusion effectively minimizes microwave reflection. The P-E hysteresis study reveals that the blended films exhibit high performance in terms of the parameters. The electromechanical coupling factor has been enhanced for 10 % Nafion inclusion. These findings suggest that the blended films have potential applications in flexible piezoelectric sensors, capacitors, memory, and microwave devices.

Synthesis and electropolymerization of a selenophene based chemiluminescent monomer and its use in blood detection

A new selenophene based trimeric chemiluminescent compound, namely 5,7-di(selenophen-2-yl)-2,3-dihydrothieno[3,4-d]pyridazine-1,4-dione (S2T-Lum), was synthesized in two steps via electron donor-acceptor-donor approach. Its chemiluminescent reaction with hydrogen peroxide was investigated in an alkaline solution in the presence of various catalysts such as different metal ions, hemin and blood samples and the results were compared with its thiophene analogue (T2T-Lum) and luminol. It was found that S2T-Lum was very sensitive to copper(II) and iron(III) ions, and blood samples. Also, it can be easily concluded that S2T-Lum as a new member of luminol type compounds is a potential candidate for the detection of blood findings in forensic science. Furthermore, S2T-Lum has an irreversible oxidation peak at 1.28 V vs Ag/AgCl, which is responsible from its electropolymerization. S2T-Lum was successfully polymerized electrochemically via potentiodynamic electrolysis without cleavage of its chemiluminescent active appendage. To the best of our knowledge, its corresponding polymer PS2T-Lum film is the first member of selenophene based luminol type electroactive polymers.

How Does Triclocarban Affect Sulfur Transformation in Anaerobic Systems?

Triclocarban (TCC), as a typical antimicrobial agent, accumulates at substantial levels in natural environments and engineered systems. This work investigated the impact of TCC on anaerobic sulfur transformation, especially toxic H2S production. Experimental findings revealed that TCC facilitated sulfur flow from the sludge solid phase to liquid phase, promoted sulfate reduction and sulfur-containing amino acid degradation, and largely improved anaerobic H2S production, i.e., 50-600 mg/kg total suspended solids (TSS) TCC increased the cumulative H2S yields by 24.76-478.12%. Although TCC can be partially biodegraded in anaerobic systems, the increase in H2S production can be mainly attributed to the effect of TCC rather than its degradation products. TCC was spontaneously adsorbed by protein-like substances contained in microbe extracellular polymers (EPSs), and the adsorbed TCC increased the direct electron transfer ability of EPSs, possibly due to the increase in the content of electroactive polymer protein in EPSs, the polarization of the amide group C═O bond, and the increase of the α-helical peptide dipole moment, which might be one important reason for promoting sulfur bioconversion processes. Microbial analysis showed that the presence of TCC enriched the organic substrate-degrading bacteria and sulfate-reducing bacteria and increased the abundances of functional genes encoding sulfate transport and dissimilatory sulfate reduction.

Electrical-Modulated Flexible Acoustic Metamaterial: Enhancing Low-Frequency Absorption via an Ionic Electroactive Polymer.

The growing concern over low-frequency noise pollution resulting from global industrialization has posed substantial challenges in noise attenuation. However, conventional acoustic metamaterials, with fixed geometries, offer limited flexibility in the frequency range adjustment once constructed. This research unveiled the promising potential of ionic electroactive polymers, particularly ionic polymer-metal composites (IPMCs), as a superior candidate to design tunable acoustic metamaterial due to its bidirectional energy conversion capabilities. The previously perceived limitations of the IPMC, including slow reaction and high energy expenditure, owning to its inherent sluggish intermediary ionic mass transport process, were astutely leveraged to expedite the attenuation of low-frequency sound energy. Both our experimental and simulation results elucidated that the IPMC can generate voltage potentials in response to acoustic pressure at frequencies significantly higher than those previously established. In addition, the peak absorption frequency can be effectively shifted by up to 45.7% with the application of a 4 V voltage. By further integration with a microperforated panel (MPP) structure, the developed metamaterial absorbers can achieve complete sound absorption, which was continuously tunable under minimal voltage stimulation across a wide frequency spectrum. In addition, a microslit structure IPMC metamaterial absorber was designed to realize modulation of the perforation rate, and the absorption peak can be shifted by up to 79.2%. These findings signify a pioneering application of ionic intelligent materials and may pave the way for further innovations of tunable low-frequency acoustic structures, ultimately advancing the pragmatic deployment of both soft intelligent materials and acoustic metamaterials.

Effect of ionic liquid on soft epoxy-amine electroactuators

Energy conversion represents a challenge in various fields of applications such as soft robotics or microfluidics technologies, particularly in terms of electromechanical coupling for actuators. The dielectric elastomers are a variety of electroactive polymers (EAP) which require high electric fields to be used as actuators. It is well-known that the presence of ionic impurities can have an influence of their electro-mechanical response under high electric field (i.e. above 1 MV/m). More precisely, it can be responsible for the bending of the sample under constant electric field. Here, we investigate the impact of a small content, i.e. from 0.1 wt% to 10 wt% of an imidazolium Ionic Liquid (IL) on the electromechanical response of a soft epoxy-amine network. The interest of this study therefore lies in its position at the frontier between dielectric polymers and ionic polymers. Dielectric spectroscopy revealed a significant increase of electric conductivity (≈2 orders of magnitude) when adding only 0.1 wt% of IL and up to 4 orders of magnitude with 10 wt% of IL at T = 20 °C for f = 10 Hz. It also evidenced the presence of the electrode polarization for all the samples doped with IL. The bending test carried out at E = 0.1 MV/m revealed no bending for pure epoxy-amine and a slow kinetics of bending for all the samples doped with IL with displacement evolving throughout the experiment (i.e. over 4 h). As evidenced by dielectric spectroscopy and bending tests, it is clear that the presence of a small quantity of ionic moieties (whether doping agent or impurity) can strongly modify the electromechanical behavior of elastomer commonly described as dielectric.

Magnetically-Actuated Endoluminal Soft Robot With Electroactive Polymer Actuation for Enhanced Gait Performance

Abstract Endoluminal devices are indispensable in medical procedures in the natural lumina of the body, such as the circulatory system and gastrointestinal tract. In current clinical practice, there is a need for increased control and capabilities of endoluminal devices with less discomfort and risk to the patient. This paper describes the detailed modeling and experimental validation of a magneto-electroactive endoluminal soft (MEESo) robot concept that combines magnetic and electroactive polymer (EAP) actuation to improve the utility of the device. The proposed capsule-like device comprises two permanent magnets with alternating polarity connected by a soft, low-power ionic polymer-metal composite (IPMC) EAP body. A detailed model of the MEESo robot is developed to explore quantitatively the effects of dual magneto-electroactive actuation on the robot’s performance. It is shown that the robot’s gait is enhanced, during the magnetically-driven gait cycle, with IPMC body deformation. The concept is further validated by creating a physical prototype MEESo robot. Experimental results show that the robot’s performance increases up to 68% compared to no IPMC body actuation. These results strongly suggest that integrating EAP into the magnetically-driven system extends the efficacy for traversing tract environments.

High performance PVC/ [AMI]mNTF2 ionic gel sensors for smart wearable applications

Plasticized polyvinyl chloride (PVC) gel as an electroactive polymer material has attracted increasing interest for the construction of flexible devices with the integration of actuation and self-sensing. However, the insufficient sensing ability of traditional PVC gels limits their applications. In this paper, a PVC ionic gel sensor based on the physical blending of PVC gel and the ionic liquid 1-allyl-3-methylimidazolium bisimide ([AMI]mNTF2) is presented. With the addition of ionic liquids, the PVC molecular chains and ions formed stable conductive pathways, resulting in increased conductivity and sensing performance of the PVC gel. The proposed sensor exhibits excellent sensing properties of high resolution (0.12 %) and fast response time (95 ms), along with high sensitivity (GF=27.8), which is more than seven times that of the traditional PVC gel. Furthermore, it was successfully utilized for human motion detection and remote control of a robotic hand, demonstrating the feasibility of the sensor for smart wearable applications in the future.

Electro-active polymer hydrogels exhibit emergent memory when embodied in a simulated game environment

Electro-active polymer hydrogels exhibit emergent memory when embodied in a simulated game environment

Pneumatic Bellow Actuator with Embedded Sensor Using Conductive Carbon Grease.

The present work demonstrates the manufacturing process of a pneumatic bellow actuator with an embedded sensor, utilizing a novel manufacturing approach through the complete use of additive manufacturing techniques, such as direct ink writing (DIW) and traditional fused deposition modeling (FDM) methods. This study is innovative in its integration of a dielectric electroactive polymer (DEAP) structure with sensing electrodes made of conductive carbon grease (CCG), showcasing a unique application of a 3D-printed DEAP with CCG electrodes for combined DEAP sensing and pneumatic actuation. Initial experiments, supported by computational simulations, evaluated the distinct functionality of the DEAP sensor by itself under various pressure conditions. The findings revealed a significant change in capacitance with applied pressure, validating the sensor's performance. After sensor validation, an additive manufacturing process for embedding the DEAP structure into a soft pneumatic actuator was created, exhibiting the system's capability for dual sensing and actuation, as the embedded sensor effectively responded to applied actuation pressure. This dual functionality represents an advancement in soft actuators, especially in applications that require integrated and responsive actuation and sensing capabilities. This work also represents a preliminary step in the development of a 3D-printed dual-modality actuator (pneumatic and electrically activated DEAP) with embedded sensing.

An experimental parametric analysis of the acoustic response in dielectric elastomer loudspeakers

This article presents an experimental parametric analysis of dielectric elastomer (DE) loudspeakers, which generate sound by means of soft lightweight electroactive polymer membranes, with no need for electromagnetic actuators. Attention is set on a simple topology, which consists of a DE actuator membrane deformed out-of-plane in a conical shape between fixed frames. Different scaled replicas of the system were built, featuring different diameters and elastomer membrane thickness, with the aim of highlighting the dependence of the acoustic response on the design parameters. An experimental analysis of the effect of different electrical and mechanical pre-loads was also carried out. Results suggest that the acoustic response is affected by both geometrical factors, possible effects of aero-elastic interactions, and the level of mechanical stress acting on the DE membrane. These findings provide valuable insights for the optimisation of DE loudspeaker design and operational parameters.