Transparent Ionogels Research Articles

Transparent ionogel balancing rigidity and flexibility with prolonged stability for ultra-high sensitivity temperature sensing

In the realm of modern flexible electronics, temperature sensors are pivotal, driving transformative advancements in electronic skins, healthcare monitoring systems, and intelligent firefighting technologies. However, impediments such as diminished temperature sensitivity, the dichotomy of rigidity versus flexibility, and compromised long-term stability hinder their full potential, adversely affecting sensor efficacy and reducing device longevity. In this research, we propose an innovative methodology for synthesizing P(HFA-co-SBMA)/[LI-BMIM] ionogels via a meticulously engineered ionic liquid system. This technique engenders temperature sensors with unparalleled sensitivity and adaptability, boasting tailor-made mechanical properties that achieve a harmonious balance between stiffness and malleability, alongside enhanced environmental tolerance. The fabricated ionogels, distinguished by their intrinsic conductivity, demonstrate superior mechanical performance, evidenced by a Young’s modulus of 44.74 MPa, high strength (7.79 MPa), and elevated toughness of 7.36 MJ/m3, coupled with notable transparency (∼90.7 %). These sensors display remarkable environmental endurance and remarkable temperature sensitivity (−9.81 % °C−1 and a B-value of 3894.6 K), achieving a high linear correlation coefficient (R2 = 0.997) across a broad operating spectrum. Leveraging density functional theory (DFT) analyses, we unravel the enhanced ion transport dynamics, validating the efficacy of our approach. By integrating 3D printing, mold casting, and in-situ polymerization techniques, we streamline the custom fabrication of miniaturized flexible ionogel sensors, enhancing the design, development, and production of sensors endowed with ideal characteristics.

A Strong and Highly Transparent Ionogel Electrolyte Enabled by In Situ Polymerization-Induced Microphase Separation for High-Performance Electrochromic Devices.

Electrochromic devices built with ionogel electrolytes are seen as a pivotal step toward the future of quasi-solid electrochromic devices, due to their striking properties like exceptional safety and high ionic conductivity. Yet, the poor mechanical strength of electrolyte of these devices remains a constraint that hampers their advancement. As a resolution, this research explores the use of a robust, transparent ionogel electrolyte, which is designed using an in situ microphase separation strategy. The ionogels are highly transparent and robust and exhibit excellent physicochemical stability, including a wide electrochemical window and high temperature tolerance. Benefitting from these properties, a high-performance electrochromic device is fabricated through in situ polymerization with the ionogels, PPRODOT as the electrochromic layer, and PEDOT: PSS as the ion storage layer, achieving high transmittance contrast (43.1%), fast response (1/1.7 s), high coloring efficiency (1296.4 cm2 C-1), and excellent cycling endurance (>99.9% retention after 2000 cycles). In addition, using ITO-poly(ethylene terephthalate) as flexible substrates, a deformable electrochromic device displaying high stability is realized, highlighting the potential use in functional wearables.

Self-healing transparent ionogel polymerized by liquid metal for strain sensor

Flexible electronic devices, sensing human movement and monitoring physiological signals, might be useful for performing research in the area of intelligent detection. Gallium (Ga), a liquid metal (LM), is often used as a soft conductive material in the form of droplets because of its unique properties. Herein, a liquid metal-induced ionogel is synthesized by polymerizing acrylic acid (AA) with the existence of poly(diallyldimethylammonium chloride) (PDDA) and Ga droplets. In the system, the free radical formed from Ga oxidation process initiates the polymerization of AA. Meanwhile, the Ga3+ produced by Ga oxidation forms a coordination with the –COO− on PAA chains. The coordination crosslinking sites create slip when the gel is exposed to external force, increasing the stretchability (5000 %) of the ionogel. When the Ga droplets are completely oxidized to Ga3+, the gel changes from silvery gray to transparent (80 %). In addition, the ionic liquids and the electrostatic interactions within the network enable the resultant ionogel anti-dehydration (98 %) and self-healing performances in a wide temperature range (-20 ∼ 20 °C). The liquid metal-induced ionogel can be assembled into a flexible sensor with adequate sensitivity, rapid response time (240 ms), and cyclic stability, demonstrating human movement patterns with accuracy to keep track of physiological signs.

Combining Promising Electrolyte Research and 3D Printing: Ionic Liquid Based Printable Membrane Materials

As promising components in energy devices such as fuel or solar cells and batteries ionic liquids (ILs) are discussed due to their promising properties. These salts with melting points below 100 °C show e.g., high thermal and electrochemical stability, high ionic conductivities and non-flammability, making them interesting candidates for use as electrolytes.[1] One of the most pressing global issues of our time, when disregarding the current COVID19 crisis, is the climate change with its well-known challenges concerning the climate policy and the energy economy. In this context due to their many benefits, the aforementioned fuel cells and batteries are being discussed as potential appliances, although there are some disadvantages attached to these technologies. Most polymer-electrolyte-membrane (PEM) fuel cells work with Nafion®, a sulfonated fluorocopolymer, as their membrane. Nafion® however loses conductivity at higher temperatures due to dehydration, limiting its operation temperature to around 80 °C at ambient pressure.[2] ILs are considered compounds that can overcome these limitations as they offer high conductivities even at elevated temperatures.For the applications as electrolytes in the aforementioned systems the immobilization of the ILs is necessary, however, to prevent leaking and realize proper function.[1] The resulting ionogels (IGs) then combine the properties of the polymer matrix, i.e. its mechanical stability, with the characteristics of the respective IL. A suitable method to realize precise geometries and shapes for these membranes is given by 3D printing, which offers adaptable electrolyte design.[3] The synthesis and characterization of ILs for ion (specifically proton) conduction is the aim of this work. These ILs exhibit wide electrochemical and thermal stability windows. The ionic conductivities of the investigated compounds range between 10-2 - 10-4 S/cm at elevated temperatures. The ILs are furthermore investigated under aspects of ion and proton transport via different spectroscopy methods.[3,4] Moreover, the ILs are immobilized in different matrix materials to provide flexible and transparent IGs that contain up to 80 wt% of IL. Additionally, successful 3D-printing and structuring of the IGs is also demonstrated.[3] [1] M. Martinez, et al, Journal of Power Sources, 2010, 195, 5829-5839.[2] J. Le Bideau, et al., Chem. Soc. Rev., 2011, 40, 907-925.[3] K. Zehbe, et al., Energy Fuels, 2019, 33, 12885-12893.[4] Z. Wojnarowska, et al., ACS Appl. Mater. Interfaces, 2021, 13, 30614–30624.

Enhanced stretchability and robustness towards flexible ionotronics via double-network structure and ion-dipole interactions

Ionic conductive gels enabled by ionic liquids (ionogels) are promising candidates for flexible electronics due to less concerns on liquid evaporation and leakage. However, it is still a challenge to simultaneously enhance the strength and stretchability for an ionogel. Here, we report a mechanically robust and stretchable ionogel, employing fluorinated acrylic monomers to construct double network (DN) structure and ion-dipole interactions between ionic liquid and the resulted polymer backbone. The highly transparent ionogels present excellent mechanical properties, with ultimate stretchability up to 784% and strength 5.6 MPa. Noticeably, the addition of ionic liquid up to 30% results in a substantial increase of stretchablity without sacrificing the ultimate stress, due to the strong ion-dipole interactions. With a good conductivity (10−4 to 10−5 S cm−1), the ionogels can be used as flexible conductors for electroluminescent devices and wearable strain sensors, both displaying excellent performance. This study provides a practical strategy on the fabrication of robust and stretchable ionogels for flexible ionotronics.

Stretchable and transparent ionogel-based heaters.

Transparent heaters (THs) are widely used for various applications, such as in smart windows, deicers, defoggers, displays, and thermotherapy pads. The rapid development of flexible electronics has led to a demand for flexible and even stretchable THs. At present, most stretchable THs are designed using a combination of electronically conductive networks and flexible polymer materials. Electronic THs still face common challenges, such as a transparency-conductance trade-off, non-uniform heating, and poor interfacial adhesion. In this work, an ionic TH is reported based on a stretchable and transparent ionogel. Joule heating from an ionic current induced by alternating voltage functions as the heating source. This ionogel-based TH exhibits excellent and steady mechanical, optical, electrical, and thermal properties, simultaneously solving the abovementioned three problems relating to electronic THs. Two simple applications of this ionogel-based TH are demonstrated: deicing and boiling water. This reported ionogel-based TH provides a new material choice and heating principle to compete with conventional electronic TH technology.

Protic Ionic Liquid Based 3D Printable Ionogels for Applications As Electrolytes

When disregarding the current COVID19 crisis the climate change is one of the most pressing global issues with its well-known challenges concerning the energy economy and climate policy. In this context due to their many benefits, fuel cells and batteries are being discussed as potential applications. These technologies are not without some disadvantages themselves, though. Most polymer electrolyte membrane (PEM) fuel cells work with Nafion®, a sulfonated fluorocopolymer, as their membrane, which loses conductivity at higher temperatures due to dehydration, which limits the operation temperature to around 80 °C at ambient pressure. [1] As a result alternative membrane materials are needed which can preferably be designed with defined geometries and sizes and show high ion mobilities and corresponding ionic conductivities at elevated temperatures.As promising components in energy devices such as fuel or solar cells and batteries ionic liquids (ILs) are discussed due to their promising properties. These salts with melting points below 100 °C show high thermal and electrochemical stability, non-flammability and high ionic conductivities. For the applications mentioned above the immobilization of the ILs is necessary to realize proper function and prevent leaking. [2] The immobilization of the ILs can be realized in three different ways: 1. swelling of polymers in the IL, 2. polymerization of polymerizable ILs and 3. polymerization of vinyl-monomers in an IL. [3] The resulting ionogels (IGs) can then combine for example the characteristics of the respective IL with the useful properties of the polymer, i.e. its mechanical stability. To realize precise shapes and geometries for the membrane materials stereolithography and 3D-printing of the respective IGs provide a suitable method. [4]The aim of this study is the synthesis and characterization of ILs for proton-conduction. The ionic conductivities of these compounds range between 10-2 - 10-4 S/cm at elevated temperatures. Moreover, these ILs exhibit wide electrochemical (e. g. ΔE up to 3 V) and thermal stability windows (Td ≥ 230 °C) and are therefore promising for ion transport at elevated temperatures. NMR-studies also provide information about their ion mobility. Furthermore the ILs are immobilized via two of the aforementioned methods to provide flexible and transparent IGs that contain up to 80 wt% of IL. These IGs display promising thermal and mechanical stability and reach ionic conductivities of up to 10-3 S/cm at elevated temperatures. Successful 3D-printing and therefore structuring of IGs can also be demonstrated.[1] Martinez, et al., Journal of Power Sources, 2010, 195, 5829–5839.[2] Le Bideau, L. Viau, A. Vioux, Chem. Soc. Rev., 2011, 40, 907–925.[3] Lu, F. Yan, J. Texter, Progress in Polymer Science, 2009, 34, 431-448.[4] Zehbe, A. Lange, A. Taubert, Energy Fuels, 2019, 33, 12885-12893.

Adhering Low Surface Energy Materials without Surface Pretreatment via Ion–Dipole Interactions

Low surface energy materials resist adhesion due to their chemical inertness and non-wetting properties. Herein, we report the creation of a transparent ionogel adhesive that uses ion-dipole interactions to achieve a higher bonding performance to polytetrafluoroethylene (PTFE) relative to most commercial glues. The ionogel adhesive is composed of a poly(hexafluorobutyl acrylate-co-methyl methacrylate) random copolymer and a hydrophobic ionic liquid. The prepared ionogel can adhere to various hydrophobic substrates, such as PTFE, polypropylene, and polyethylene, as well as hydrophilic glass, ceramics, and steel. The design strategy and adhesion behavior are well interpreted using the density functional theory calculations and molecular dynamics simulations. The straightforward ultraviolet-curing method, high optical clarity, versatile adhesion ability, and reversible adhesion capabilities make this high-performance adhesive a promising product for commercialization.

A highly transparent ionogel with strength enhancement ability for robust bonding in an aquatic environment.

An underwater adhesive with strong, fast and stable adhesion ability has become an urgent requirement for various industrial applications. Herein, a highly transparent ionogel based on a fluorine-rich poly(ionic liquid) and the corresponding ionic liquid monomer has been developed and used as an underwater adhesive. Strong and stable underwater adhesion can be realized by taking advantage of the excellent interface adaptability and high mechanical strength of this ionogel. The underwater adhesion strength could reach as high as 5.18 ± 0.27 MPa. In addition, it can also realize robust bonding over a wide pH range (0-14). A waterproof transparent tape based on the ionogel has also been developed and it can carry out repair work in wet and aquatic environments.

Stretchable and Transparent Ionogels with High Thermoelectric Properties

AbstractStretchable electronic materials and devices have important applications in flexible electronic systems including wearable electronics and bioelectronics. Convenient electricity generation such as thermoelectric conversion is required for the flexible electronic systems. Hence, it is development of high‐performance thermoelectric materials with high mechanical stretchability would be highly desirable. Here, stretchable and transparent ionogels with high thermoelectric properties are demonstrated. The ionogels made of elastomeric waterborne polyurethane and 1‐ethyl‐3‐methylimidazolium dicyanamide (EMIM:DCA, an ionic liquid) are prepared by solution processing. Their mechanical and electrical properties depend on the loading of EMIM:DCA. The ionogels with 40 wt% EMIM:DCA can have a high mechanical stretchability of up to 156%, low tensile strength of 0.6 MPa, and low Young's modulus of 0.6 MPa. They also exhibit a high ionic thermovoltage of 34.5 mV K−1, high ionic conductivity of 8.4 mS cm−1 and low thermal conductivity of 0.23 W m−1 K−1 at a relative humidity of 90%. As a result, it can have a high ionic figure of merit (ZTi) of 1.3 ± 0.2. Both the thermovoltage and the ZTi value are the highest for stretchable thermoelectric materials. They can be used in ionic thermoelectric capacitors to convert heat into electricity.

Self-Sustainable, self-healable, Load Bearable and Moldable stimuli responsive ionogel for the Selective Removal of Anionic Dyes from aqueous medium

Among the tested strategies to remove the toxic dyes from the aquatic environment, absorption is widely preferred owing to its ease of formation, lower cost and modulating ability of the absorbents used. Designing advance absorbents that offer higher absorptivity, selectivity, reusability, moldability and high pre-concentration factor for the analyst is a challenging task yet to be achieved. Herein, we had designed new age low molecular weight gelator from prototypical molecular gelators, an ionic liquid based gelator; 1-n-hexadecyloxy-carbonylmethylpyridinium bromide (C16EPyrBr) that exhibited unusual, unprecedented stimuli responsive reversible transition from opaque to transparent ionogel due to the change in the gel microstructure from lamellar for the opaque ionogel to cylindrical for the transparent ionogel. Small angle neutron scattering and scanning and scanning electron microscopy measurements characterized the microstructure and morphology of the ionogel respectively. Although having lower molecular weight based, the ionogel show excellent tolerance against the salinity (1500 mM concentration of NaCl), offer good mechanical strength and have self-healing, self-sustaining, and load bearing characteristics. The ionogel could be loaded in apparatus like dialysis membrane and syringe with 99% removal efficiency and can selectively remove the anionic dye, methyl orange from the aqueous medium even after 20 cycles. As a final thought, the low molecular weight ionic liquid based gelator could be a promising alternative to the traditional anionic dye absorbents.

Silica-Based Ionogels Deposited By Spray Coating for All-Solid-State Lithium-Ion Microbatteries

The emerging market of the Internet of Things, smart objects and others increase the demand for micro energy sources. Rechargeable Li-ion batteries are a well-known technology for energy storage. However, safety issues and high production costs constrain progress. Research on solid electrolytes, such as LiPON, was performed to evade leakage. But LiPON suffers from low ionic conductivity and a cost and time intensive production process. Another approach is the substitution of volatile and flammable organic electrolyte solvents with ionic liquids (IL), which display negligible vapor pressure and wide chemical, electrochemical, and thermal stability. Electrolyte solution based on ILs can be confined into inorganic porous networks forming so-called ionogels (IG), which are investigated as solid electrolyte materials. IGs combine low hazard and good ionic conductivity [1]. Silica-based IGs compatible with Li/LiCoO2 systems were prepared in a one-pot sol-gel process. The composition of the IG precursor solution and the influence of trifluoroacetic acid as catalyst were studied to obtain a fast condensation. Homogeneous and transparent IGs were obtained with a gelation time of less than 12 h. The physical properties of the host matrix were characterized by N2 sorption and SEM. The silica host matrix is a 3D network predominantly built from 3-fold condensed silicon centres. Its structure changes from densely packed silica particles to open porous architecture. The electrochemical performances of the IG deposited by spray coating under ambient contitions were evaluated by impedance spectroscopy measurements. First results show that these promising IGs may be successfully used as electrolyte in Li/LiCoO2 cells, with ionic conductivities up to 0.15 mScm-1. The coin cell batteries prepared with our IGs did not show dendritic growth after more than 100 cycles of galvanostatic cycling at a C/4 rate.

Multifunctional Self-Healing Ionogels from Supramolecular Assembly: Smart Conductive and Remarkable Lubricating Materials.

Self-healing ionogel is a promising smart material because of its high conductivity and reliable stimuli responsiveness upon mechanical damage. However, self-healing ionogels possessing rapid, complete recovery properties and multifunctionality are still limited. Herein, we designed a new d-gluconic acetal-based gelator (PB8) bearing a urea group in the alkyl side chain. Interestingly, the balance between hydrophilicity and hydrophobicity of the molecule is achieved. Thus, PB8 could form transparent ionogels because of its excellent affinity to ionic liquids (ILs), which exhibited appropriate mechanical strength, high viscoelasticity, and efficient self-healing properties. The presence of synergistic effects from hydrogen bonding, π-π stacking, and interactions between the urea-containing side chains was responsible for the self-assembly of gelators in ILs and the self-healing property mainly related to the side chains of PB8. Interestingly, the transparent PB8-IL4 ionogel possessed high conductivity and mechanical strength, moldable and injectable properties, and rapid and complete self-healing characteristics (complete recovery within 14 min), which showed excellent performance as a smart ionic conductor. Furthermore, the self-healing PB8-based ionogels with anticorrosion properties are a remarkable lubricating material in the steel-steel contact and exhibited excellent lubricating performances. Overall, an efficient PB8-based ionogel with self-healing properties has been developed for potential use both as a smart electrical conductor and as a high-performance lubricating material. The unique structure of PB8 bearing a urea group in the side chain is found to be responsible for the multifunctional ionogel formation.

Thermo-Switchable de Novo Ionic Liquid-Based Gelators with Dye-Absorbing and Drug-Encapsulating Characteristics.

An ionic liquid-based surfactant with ester functionality self-aggregates in an aqueous medium and forms ionogels at 8.80% (w/v) concentration at physiological pH. The ionogel exhibited a remarkable change in its appearance with temperature from fibrillar opaque to transparent because of the dynamic changes within its supramolecular structure. This gel-to-gel phase transition occurs below the melting point of the solid ionic liquid. The ionogels were investigated using turbidity, differential scanning calorimetry, scanning electron microscopy (SEM), field emission SEM (FE-SEM), inverted microscopy, transmission electron microscopy imaging, Fourier transform infrared spectroscopy, and rheological measurements. The fibrillar opaque ionogel and transparent ionogel were studied for their ability to absorb dyes (methyl orange and crystal violet) and to encapsulate drugs (diclofenac sodium and imatinib mesylate).

(Invited) Highly Stretchable and Transparent Ionogels as Nonvolatile Conductors for Dielectric Elastomer Transducers

Large deformation of soft materials is harnessed to provide functions in the nascent field of soft machines. This paper describes a new class of systems enabled by highly stretchable, transparent, stable ionogels. We synthesize an ionogel by polymerizing acrylic acid in ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate ([C2mim][EtSO4]). The ionogel exhibits desired attributes of adequate conductivity (0.22 S m−1), low elastic modulus (∼3 kPa), large rupturing stretch (∼4.6), and negligible hysteresis and degradation after cyclic stretches of large amplitude. Using the ionogel and a dielectric elastomer, we fabricate electromechanical transducers that achieve a voltage-induced areal strain of 140%. The ionogel is somewhat hygroscopic, but the transducers remain stable after a million cycles of excitation in a dry oven and in air. The transparency of the ionogels enable the transducers with conductors placed in the path of light, and the nonvolatility of the ionogels enable the transducers to be used in open air.

Preparation of High-Performance Ionogels with Excellent Transparency, Good Mechanical Strength, and High Conductivity.

Ionogels offer great potential for diverse electric applications. However, it remains challenging to fabricate high-performance ionogels with both good mechanical strength and high conductivity. Here, a new kind of transparent ionogel with both good mechanical strength and high conductivity is designed via locking a kind of free ionic liquid (IL), i.e., 1-ethyl-3-methylimidazolium dicyanamide ([EMIm][DCA]), into charged poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS)-based double networks. On the one hand, the charged PAMPS double network provides good mechanical strength and excellent recovery property. On the other hand, the free [EMIm][DCA] locked in the charged double network through electrostatic interaction offers ionic conductivity as high as ≈1.7-2.4 S m-1 at 25 °C. It is demonstrated that the designed ionogel can be successfully used for a flexible skin sensor even under harsh conditions. Considering the rationally designed chemical structures of ILs and the diversity of charged polymer networks, it is envisioned that this strategy can be extended to a broad range of polymer systems. Moreover, functional components such as conducting polymers, 0D nanoparticles, 1D nanowires, and 2D nanosheets can be introduced into the polymer systems to fabricate diverse novel ionogels with unique functions. It is believed that this design principle will provide a new opportunity to construct next-generation multifunctional ionogels.

Development of ion conducting ionic liquid-based gel polymer electrolyte membrane PMMA/BMPyr.TFSI - With improved electrical, optical, thermal and structural properties

Ionogel membranes are materials of colossal intrigue worldwide because of their utilization as excellent substitutes of the liquid electrolytes or as separators in ionic gadgets including batteries, fuel cells, supercapacitors, energy units, and so on. In the present work, transparent ionogel composites of PMMA/1-butyl-1-methylpyrrolidinium bis(trifluoromethyl sulfonyl imide) (100/0, 90/10, 80/20, 70/30) were prepared to be used for optical devices. The impact of varying amount of ionic liquid in the PMMA matrix in weight ratios was compared with the undoped polymer blend. The prepared membrane was characterized for thermal, conductivity, optical and for morphological examinations. In addition, the current voltage characteristics of prepared films have been performed at room temperature. The addition of ionic liquid to the polymer matrix improves the properties by having better thermal stability, enhanced luminescence intensity and making the membrane more amorphous. Among these, PMMA with 20% having a glass transition temperature of 44.95°C exhibits superior performance with the fairly smooth transparent surface, increased flexibility, enhanced thermal stability, highest ionic conductivity, the maximum capacitance of 0.403∗10−6Fcm−2, non ohmic behaviour and photoluminescence property.

Hybrid organic-inorganic dyeionogels: Reversibly pH-responsive materials based dye-ionic liquids with improved structural stability and flexibility

Hybrid organic-inorganic (HOI) based on f-PMMA-SiO2 materials were synthesized by in situ polymerization of methyl methacrylate (MMA) monomer and tetraethoxysilane (TEOS) precursor with the assistance of 3-trimethoxysilyi-propyl-methacrylate (KH-570) as coupling agent. Dye-ionic liquids and the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide [Bmim][NTf2] and 1-butyl-3-methylimidazolium methyl orange [Bmim][MO] were used as guests for the synthesis of pH-responsive functional poly(methylmethacrylate) (f-PMMA-SiO2) ionogels. The pendent groups of KH-570 allow its linkage to both the silica and MMA, leading to a uniform composite. Optical inspection of the ionogels suggests that the materials are transparent and homogeneous without macroscopic defects. The hybrid ionogels possess a high ionic conductivity of 10−4Scm−1 at 373K. The bulky gel shows tunable mechanical stability with compressive strength up to 4MPa that is markedly dependent on the f-PMMA and the ionic liquids incorporation. In particular, color change is clearly observed when the ionogels exposed to proton-containing solution. Moreover, HOI ionogels exhibit significantly enhanced structural integrity in both proton-containing aqueous and organic solution. The resulting material is thus an interesting prototype of flexible, stable and transparent ionogels combining the mechanical properties of the hybrid with the functionality of the ionic liquids.

Highly Stretchable and Transparent Ionogels as Nonvolatile Conductors for Dielectric Elastomer Transducers

Large deformation of soft materials is harnessed to provide functions in the nascent field of soft machines. This paper describes a new class of systems enabled by highly stretchable, transparent, stable ionogels. We synthesize an ionogel by polymerizing acrylic acid in ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate ([C2mim][EtSO4]). The ionogel exhibits desired attributes of adequate conductivity (0.22 S m(-1)), low elastic modulus (∼3 kPa), large rupturing stretch (∼4.6), and negligible hysteresis and degradation after cyclic stretches of large amplitude. Using the ionogel and a dielectric elastomer, we fabricate electromechanical transducers that achieve a voltage-induced areal strain of 140%. The ionogel is somewhat hygroscopic, but the transducers remain stable after a million cycles of excitation in a dry oven and in air. The transparency of the ionogels enable the transducers with conductors placed in the path of light, and the nonvolatility of the ionogels enable the transducers to be used in open air.