Pipe contaminant detection holds considerable importance within various industries, such as the aviation, maritime, medicine, and other pertinent fields. This capability is beneficial for forecasting equipment potential failures, ascertaining operational situations, timely maintenance, and lifespan prediction. However, the majority of existing methods operate offline, and the detectable parameters online are relatively singular.
View Article and Find Full Text PDFMicrosyst Nanoeng
February 2023
Ultrasonic fluid bubble detection is important in industrial controls, aerospace systems and clinical medicine because it can prevent fatal mechanical failures and threats to life. However, current ultrasonic technologies for bubble detection are based on conventional bulk PZT-based transducers, which suffer from large size, high power consumption and poor integration with ICs and thus are unable to implement real-time and long-term monitoring in tight physical spaces, such as in extracorporeal membrane oxygenation (ECMO) systems and dialysis machines or hydraulic systems in aircraft. This work highlights the prospect of capacitive micromachined ultrasonic transducers (CMUTs) in the aforementioned application situations based on the mechanism of received voltage variation caused by bubble-induced acoustic energy attenuation.
View Article and Find Full Text PDFWith the increasing demand for multidirectional vibration measurements, traditional triaxial accelerometers cannot achieve vibration measurements with high sensitivity, high natural frequency, and low cross-sensitivity simultaneously. Moreover, for piezoresistive accelerometers, achieving pure axial deformation of the piezoresistive beam can greatly improve performance, but it requires the piezoresistive beam to be located in a specific position, which inevitably makes the design more complex and limits the performance improvement. Here, a monolithically integrated triaxial high-performance accelerometer with pure axial stress piezoresistive beams was designed, fabricated, and tested.
View Article and Find Full Text PDFTactile sensors have been widely used in the areas of health monitoring and intelligent human-machine interface. Flexible tactile sensors based on nanofiber mats made by electrospinning can meet the requirements of comfortability and breathability for wearing the body very well. Here, we developed a flexible and self-powered tactile sensor that was sandwich assembled by electrospun organic electrodes and a piezoelectric layer.
View Article and Find Full Text PDFA micromachined resonator immersed in liquid provides valuable resonance parameters for determining the fluidic parameters. However, the liquid operating environment poses a challenge to maintaining a fine sensing performance, particularly through electrical characterization. This paper presents a piezoelectric micromachined cantilever with a stepped shape for liquid monitoring purposes.
View Article and Find Full Text PDFIn a fiber-optic disk accelerometer, the strain distribution of sensing fiber is crucial for the improvement of sensitivity. The distribution characteristics of axial and radial strain in the sensing fiber are analyzed by the finite-element method, and the influence of strain distribution on the sensitivity of accelerometer is studied. Sensors with different outer radii of sensing fiber coils are designed and manufactured, and their performance is tested.
View Article and Find Full Text PDFAll-fiber modulators and switches have drawn great interest in the photonics domain, and they are applied in viable photonic and optoelectronic devices. In this work, with the assistance of an agarose membrane, aspherical gold nanoparticles are embedded on the surface of the microfiber treated with the piranha solution. An all-fiber Mach-Zehnder interferometer was used to realize a low-cost, low-loss, and conveniently prepared all-fiber phase modulator.
View Article and Find Full Text PDFThe method of superimposing multiple phase patterns to generate and deflect multi Airy beams is proposed in this paper. A Dammann grating and an optimized splitting grating are superimposed, respectively, with an Airy cubic phase pattern to generate an array of 4×4 equal-space Airy beams. By adding a deflection grating to the superimposed phase patterns, the transverse self-accelerated Airy beams array can be deflected arbitrarily in two-dimensional plane.
View Article and Find Full Text PDFTo controllably deflect the Airy beam in a wide range dynamic, the method of combining the classical Airy cubic phase with a diffraction blazed grating phase was adopted in this paper. By dynamically adjusting the grating parameters, the transverse self-accelerating Airy beam allows arbitrary deflection, and the deflected position can be controlled precisely. The mathematical model of the Airy beam optical field distributions generated by the combined phase patterns were proposed to explain the feasibility.
View Article and Find Full Text PDF