Miniaturized gas pumps based on electromagnetic effect have been intensively studied and widely applied in industries. However, the electromagnetic effect-based gas pumps normally have large sizes, high levels of noises and high power consumption, thus they are not suitable for wearable/portable applications. Herein, we propose a high-flowrate and high-pressure load valveless piezoelectric micropump with dimensions of 16 mm*16 mm*5 mm. The working frequency, vibration mode and displacement of the piezoelectric actuator, the velocity of gas flow, and the volume flowrate of the micropump are analyzed using the finite element analysis method. The maximum vibration amplitude of the piezoelectric actuator reaches ~29.4 μm. The output gas flowrate of the pump is approximately 135 mL/min, and the maximum output pressure exceeds 40 kPa. Then, a prototype of the piezoelectric micropump is fabricated. Results show that performance of the micropump is highly consistent with the numerical analysis with a high flowrate and pressure load, demonstrated its great potential for wearable/portable applications, especially for blood pressure monitoring.

Organic piezoelectric materials have attracted significant interest for applications in sensing, energy harvesting, and flexible electronics. However, its piezoelectric properties are yet to be improved. This study introduces a facile strategy to fabricate homogenous and dense polyvinylidene fluoride (PVDF) films with high piezoelectric performance via anhydrous CaCl₂ doping. The strong ion–dipole interaction between Ca²⁺ and F atoms, along with directional dipole alignment under an electric field at elevated temperature, as verified by molecular dynamics simulations and material characterizations. This results in an impressive β-phase content of 92.78% and a piezoelectric coefficient of 29.26 pm/V. A piezoelectric device fabricated from this PVDF film delivers an output voltage exceeding 12 V under external pressure and maintains stability over 60,000 cycles. When integrated with an LC resonant circuit, it functions as a wireless sensor for real-time motion monitoring. This scalable approach significantly advances piezoelectric polymer performance for practical applications.

This experimental work studies the translocation of bovine serum albumin (BSA) proteins through MoS₂ nanopores. A simple method of device fabrication is developed based on dry-transfer of exfoliated MoS₂ membranes and subsequent TEM drilling, yielding MoS₂ nanopores of a few monolayers thick and diameters as small as ∼11 nm. The current-voltage relation and low-frequency current noise of the devices are characterized. Typical BSA translocation signals that possibly correspond to various orientations are observed in the MoS₂ devices, exhibiting enhanced amplitude and similar characteristics when compared to those from a silicon nitride (SiN_x) control. Furthermore, the statistical data of the signal amplitude and dwell time at various biases are analyzed. These results show opportunities of single-molecular protein analysis using MoS₂ nanopores.

Algae cells were the main sources of dissolved organic nitrogen (DON) in raw water with plenty of algae, and ultrasonic pretreatment was one of the algae-controlling methods through the damage of algae cells. However, the variation of DON concentration during the ultrasonic treatment process was not confirmed. Variation of DON concentration during the processes of low frequency ultrasound treatment of Microcystis aeruginosa was investigated. In addition, the effect of sonication on the metabolite concentration, algae cellar activity and the subsequent coagulation performance were discussed. The results showed that after a long duration of ultrasonic (60 s), nearly 90% of the algal cells were damaged and the maximum concentration of DON attained more than 3 mg/L. In order to control the leakage extent of DON, the sonication time should be less than 30 s with power intensity of more than 1.0 W/cm(3). In the mean time, ultrasonic treatment could inhibit the reactivation and the proliferation of algal, keep the algae cell wall integrity and enhance coagulation effectively under the same condition. However, ultrasound frequency had little effect on DON at the frequency range used in this study (20-150 kHz).

Here, we present integrated nanorod arrays on microfluidic chips for fast and sensitive flow-through immunoassays of physiologically relevant macromolecules. Dense arrays of Au nanorods are easily fabricated through one-step oblique angle deposition, which eliminates the requirement of advanced lithography methods. We report the utility of this plasmonic structure to improve the detection limit of the cardiac troponin I (cTnI) assay by over 6 × 10⁵-fold, reaching down to 33.9 fg mL⁻¹ (~1.4 fM), compared with an identical assay on glass substrates. Through monolithic integration with microfluidic elements, the device enables a flow-through assay for quantitative detection of cTnI in the serum with a detection sensitivity of 6.9 pg mL⁻¹ (~0.3 pM) in <6 min, which was 4000 times lower than conventional glass devices. This ultrasensitive detection arises from the large surface area for antibody conjugation and metal-enhanced fluorescent signals through plasmonic nanostructures. Moreover, due to the parallel arrangement of flow paths, simultaneous detection of multiple cancer biomarkers, including prostate-specific antigen and carcinoembryonic antigen, has been fulfilled with increased signal-to-background ratios. Given the high performance of this assay, together with its simple fabrication process that is compatible with standard mass manufacturing techniques, we expect that the prepared integrated nanorod device can bring on-site point-of-care diagnosis closer to reality.