Dielectric gels with ultra-high dielectric constant, low elastic modulus, and excellent transparency

We designed dielectric gels, a new type of polymer-based dielectric material. By using solvents with high dielectric constants, the gels achieve a unique combination of ultra-high dielectric constant, low elastic modulus, and excellent transparency, which are extremely challenging or impossible to realize with traditional polymer dielectrics. The gels exhibit high stretchability (stretch of approximately 10) and low mechanical hysteresis. We demonstrated the use of the dielectric gels by fabricating a bioinspired tunable lens, the focal length of which can be adjusted by varying the applied voltage. We believe that the dielectric gels, as a new type of polymer dielectric, offer new opportunities for soft robotics, sensors, electronics, optics, and biomimetics. Stretchy and see-through substances known as dielectric gels may find application in soft robotics due to their capabilities of controllable movement. Insulating membranes can be stimulated to squeeze like a muscle by applying voltage pulses. Shujiang Ding from Xi'an Jiaotong University, China, and co-workers have developed a material that reduces the typically high voltages needed for movement by 50% compared with a commercial membrane. They used ultraviolet polymerization to lock liquid molecules with high charge-storing properties within a hydrocarbon chain network, producing super-insulating gels that can be extended up to 10 times their original size without damage. A bioinspired lens was fabricated by sandwiching a liquid between two gel membranes. Voltage-tunable pressure from the gels squeezed the lens and changed its focal length, similar to the changes seen in the human eye when focusing. Dielectric gels, a new type of polymer-based dielectric material have been designed. The gels achieve a unique combination of ultra-high dielectric constant, low elastic modulus, and excellent transparency, which are extremely challenging or impossible to realize by traditional polymer dielectrics. We have demonstrated the use of the dielectric gel by fabricating a bioinspired tunable lens, the focal length of which can be adjusted by varying the applied voltage. Dielectric gels offer new opportunities for soft robotics, sensors, electronics, optics, and biomimetics.