RESUMO
Polyurethane dielectric elastomer (PUDE), a typical representative of emerging intelligent materials, has advantages, such as good elasticity and flexibility, fast response speed, high electromechanical conversion efficiency, and strong environmental tolerance. It has promising applications in underwater bionic actuators, but its electromechanical properties should be improved further. In this context, the design of polyethylene glycol (PEG) single-walled carbon nanotube (SWNTs) dielectric microcapsules was adopted to balance the problem of contradictions, which conventional dielectric modification methods face between comprehensive properties (e.g., dielectric properties and modulus). Moreover, the dielectric microcapsule was evenly filled into the polyurethane fiber by coaxial spinning technology to enhance the actuation performance and instability of the electrical breakdown threshold of conventional polyurethane dielectric modification. It was revealed that the dielectric microcapsules were oriented in the polyurethane fiber, and the actuation performance of the composite fiber membrane was significantly better than that of the polyurethane fiber membrane filled with SWNTs, thus confirming that the filling design of the dielectric microcapsules in polyurethane fiber could have certain technical advantages. On that basis, this study provides a novel idea for the dielectric modification of polyurethane.
RESUMO
The development of actuators for power sources is essential for the efficient manipulation of fluids in microfluidics systems. In this work, a capacitor-type three-layer paper actuator was fabricated by sandwiching a polyelectrolyte layer between two films of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT/PSS). The paper actuator exhibited stable large electromechanical deformations in bilateral symmetry under alternating square-wave electric field. The actuation properties were examined in a function of voltage (±0.5, ±1, ±1.5, ±2, and ±2.5 V) and frequency (1, 0.5, 0.2, and 0.05 Hz). In addition, the PEDOT/PSS electrode films with different thicknesses were prepared, and the effects of actuator thickness on actuation properties were examined. As a result, it was found that the actuator displacement increased considerably with reducing actuator thickness. In addition, the actuator with a thickness of 48 µm demonstrated a maximum displacement of 5.8 mm at a voltage of 1.5 V and a frequency of 0.05 Hz. The proposed actuator can be potentially used in the development of power sources for micropumps and check valves of microfluidic devices.