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A novel ion-exchange polymer-metal composite (IPMC) actuator is fabricated by sandwiching sulfonated fluorene blocked polysulfone (SDPF- b -PSU) between two Pt nanograin sheets. With increased concentration of chlorosulfonic acid, the SDPF- b -PSU film with more sulfonic groups exhibits strong ion exchange capacity, high Li + ion conductivity, and ordered phase separation, which may contain an increased number of cations and possess larger and better interconnected inner channels for ion migration, thus providing the power to produce large force and power outputs. The SDPF- b -PSU film also exhibits enhanced mechanical performance and water uptake when compared to the pure Nafion film, providing a strong, hydrated matrix to support IPMC functions. At the driving voltage of 4 V, the SDPF- b -PSU actuator exhibits a strong force output which is 11 folds higher than that of the pure Nafion actuator. [ABSTRACT FROM AUTHOR]

The structures and working principles of a piezoelectric pump with dual vibrators are described in this paper. The output performance of the pump was analyses under different working modes. The experimental results demonstrate that changing the driving strategy can vary the performance. When the driving voltage is 60 V at 160 Hz, the maximum output pressure of the pump in the asynchronous mode is 2.18 kPa. The performance of the upper actuator working alone is better than the lower actuator working alone, and the maximum output pressure in this case is 1.3 kPa. Taking the piezoelectric pump with a single vibrator as a typical example, an optimal design method has been applied on the check valves. The performance of the pump with wheel valves is better than that with cantilever valves; the optimum thickness of the check valves is 0.188 mm. [ABSTRACT FROM AUTHOR]

• Sequential electrospinning strategy is developed to fabricate an all-nanofiber actuator. • The actuator exhibits high sensitivity, ultrafast actuation time, and excellent repeatability. • Incorporation of interconnected pores greatly enhances the shape deformation. Humidity-responsive bilayered actuators which can dynamically change their shapes under humidity gradients, have recently motivated significant interest in a wide variety of emerging fields, including artificial muscles, intelligent sensors, and smart devices. However, this kind of actuators frequently suffer from slow responsiveness, prolonged actuating period, and small deformation, which is due to the dense structure hindering the diffusion of water molecules. Herein, we employ a simple programmable electrospinning approach to fabricate a highly porous polyvinyl alcohol/polyvinyl butyral (PVA/PVB) bilayered actuator for achieving excellent humidity-triggered deformation. Benefiting from the differential affinity of the two layers to water and the elaborately structural design, the porous bilayered actuator exhibits superior actuating performance in response to humidity gradient. Briefly, only 283 ms is needed for driving the shape change, and the whole deformation merely requires 10 s; besides, large bending amplitude with the curvature of 11.2 cm−1 is achieved, and the shape deformation process can be repeated at least 30 times without fatigue. Finally, we demonstrate the porous nanofibrous actuator can be used as artificial plants to perform opening and closing motions and a self-driven detector for monitoring humidity in real-time. [ABSTRACT FROM AUTHOR]