Design of a Piezoelectric Pump Driven by Inertial Force of Vibrator Supported by a Slotted Beam

This paper introduces the design, manufacture, dynamic analysis, and experimental results of a piezoelectric pump driven by the inertial force of a vibrator supported by a slotted beam. The piezoelectric vibrator is composed of a mass block, displacement amplifier, and slotted beam fixed with both ends. In the resonant mode, the displacement amplifier drives the slotted beam to work, and produces amplitude and inertial force. In this paper, the design of the slotted beam optimizes the output of the displacement amplifier. In addition, the slotted beam supports the displacement amplifier and increases the elastic output. The pump body adopts polydimethylsiloxane (PDMS) check valves and compressible spaces to improve the output performance. This research studies the influence of stiffness and mass on the output performance by qualitatively analyzing the inertial output force of the vibrator. Nine kinds of slotted beams with different stiffnesses and different mass blocks are designed for comparison. Thereafter, an optimal structure of the piezoelectric pump is selected. The experimental results show that under a driving voltage of 700 Vpp , the maximum flowrate is 441 mL min−1 and the maximum back pressure is 25.3 kPa

Resonant-Type Piezoelectric Pump Driven by Piezoelectric Stacks and a Rhombic Micro Displacement Amplifier

To obtain a high flow rate, a resonant-type piezoelectric pump is designed, fabricated, and studied in this paper. The pump consists of four parts: a piezoelectric vibrator, a pump chamber, a check valve and a compressible space. The designed piezoelectric vibrator is composed of a rhombic micro displacement amplifier, counterweight blocks and two piezoelectric stacks with low-voltage drive and a large output displacement. ANSYS software (Workbench 19.0) simulation results show that at the natural frequency of 946 Hz, the designed piezoelectric vibrator will produce the maximum output displacement. The bilateral deformation is symmetrical, and the phase difference is zero. Frequency, voltage, and backpressure characteristics of the piezoelectric pump are investigated. The experimental results show that at a certain operating frequency, the flow rate and the backpressure of the piezoelectric pump both increase with the increase in voltage. When the applied voltage is 150 Vpp, the flow rate reaches a peak of 367.48 mL/min at 720 Hz for one diaphragm pump, and reaches a peak of 700.15 mL/min at 716 Hz for two diaphragm pumps

Biomimetic caged platinum catalyst for hydrosilylation reaction with high site selectivity

Design of artificial catalysts to mimic enzyme activity and selectivity is a challenge in the catalysis field. Here, the authors design a platinum catalyst with a porous cage ligand which shows enzyme-like properties, such as high hydrosilylation activity and substrate size selectivity, while being recyclable

Replica Symmetry Breaking in FRET-Assisted Random Laser Based on Electrospun Polymer Fiber

Spin-glass theory has been widely introduced to describe the statistical behaviors in complex physical systems. By analogy between disorder photonics and other complex systems, the glassy behavior, especially the replica symmetry breaking (RSB) phenomenon, has been observed in random lasers. However, previous studies only analyzed the statistical properties of the random laser systems with single gain material. Here, the first experimental evidence of the glassy behavior in a random laser with complex energy level structure is reported. This novel random laser is demonstrated based on the electrospun polymer fibers with the assistance of Förster resonance energy transfer (FRET). The electrospinning technology employed in the experiment herein promises high-volume production of random laser devices with multiple energy levels, enabling the comprehensive investigation of lasing properties in multi-energy level random laser system. Clear paramagnetic phase and spin-glass phase are observed in the FRET-assisted random laser under different pump energies. The RSB phase transition is verified to occur at the laser threshold, which is robust among the random lasers with different donor–acceptor ratio. The finding of RSB in FRET-assisted random laser provides a new statistical analysis method toward the laser system with complex energy level, for example, quantum cascade laser