Pattern Synthesis and Polarization Optimization of a Conical Array

A feasible method for synthesizing millimeter-wave conical array and optimizing low cross-polarization is proposed.Starting from the far-field superposition principle,an efficient approach including element mutual coupling and mounted platform effects is used to calculate the far-field patterns.A coordinate transform is applied to create polarization quantities,and a general process for the element polarized pattern transformation is performed.Corresponding numerical example is given and the desired sidelobe level and low cross-polarization are optimized.The numerical results indicate the proposed method is valid.

A Hierarchical Conical Array with Controlled Adhesion and Drop Bounce Ability for Reducing Residual Non-Newtonian Liquids

As a result of frequent food waste and environmental pollution,there has been an increasing demand for the development of packaging materials that intrinsically inhibit and reduce likelihood of non-Newtonian liquids adherence.In this work,inspired from ciliary structures on the leg of water strider,the hierarchical conical array was formed by magnetic field control and laser etching without any mask.Due to the tapered geometry of the cones and the multiscale surface roughness of the array,the droplets would bounce many times after impacting with the superhydrophobic surface(SHS)and roll off.By changing the spaces and apex angles of conical microcolumns the SHS has controlled adhesion,superior self-cleaning property and droplets bounce performance for a variety of non-Newtonian viscous liquids.After suffering from various types of damage including repeated tape tearing,finger touch and folding test,the SHS still maintained excellent superhydrophobic property,which may have potential application as all kinds of packaging interface materials.We demonstrate that the excellent droplets bounce behavior of the hierarchical array enables the efficient and robust prevention of food liquids adhesion.

Laser speckle grayscale lithography:a new tool for fabricating highly sensitive flexible capacitive pressure sensors

Achieving a high sensitivity for practical applications has always been one of the main developmental directions for wearable flexible pressure sensors.This paper introduces a laser speckle grayscale lithography system and a novel method for fabricating random conical array microstructures using grainy laser speckle patterns.Its feasibility is attributed to the autocorrelation function of the laser speckle intensity,which adheres to a first-order Bessel function of the first kind.Through objective speckle size and exposure dose manipulations,we developed a microstructured photoresist with various micromorphologies.These microstructures were used to form polydimethylsiloxane microstructured electrodes that were used in flexible capacitive pressure sensors.These-1 sensors exhibited an ultra-high sensitivity:19.76 kPa for the low-pressure range of 0-100 Pa.Their minimum detection threshold was 1.9 Pa,and they maintained stability and resilience over 10,000 test cycles.These sensors proved to be adept at capturing physiological signals and providing tactile feedback,thereby emphasizing their practical value.