Nanostructured Crosslinkable Micropatterns by Amphiphilic Dendrimer Stamping

Summary: Microcontact printing was used to deposit stable, nanostructured, amphiphilic and crosslinkable patterns of poly(amidoamine organosilicon) (PAMAMOS)‐dimethoxymethylsilyl (DMOMS) dendrimer multilayers onto silicon wafers, glass, and polyelectrolyte multilayers. The effects of dendrimer ink concentration, contact time, and inking method, on the thickness, uniformity, and stability of the resulting patterns were studied using optical microscopy, fluorescence microscopy, atomic force microscopy (AFM), and contact‐angle analysis. Microarrayed dendrimer film thickness was found to be controllable by conditions used during spin self‐assembly.

Optical micrograph of the circular patterns, obtained from a 0.5% PAMAMOS dendrimer solution, on a glass substrate.     

Voice characteristics, effects of voice therapy, and long-term follow-up of contact granuloma patients

This study evaluates the laryngoscopic findings and voice characteristics of male contact granuloma patients before and after voice therapy and at a follow-up about 9 years later. Pre- and posttherapy recordings as well as follow-up recordings were made for 19 granuloma patients. Pretherapy revealed the most salient perceptual voice characteristics were low pitch, monotony, and a high degree of vocal fry and hyperfunction. Interjudge reliability for these traits was high. Immediately following therapy the healed patients (n = 10) had a decrease in hyperfunction, vocal fry, and monotony, while the unhealed patients (n = 9) had an increase in hyperfunction and vocal fry decreased only marginally. Monotony decreased significantly in this group. As regards the acoustic analyses, no significant differences were found in mean fundamental frequency (F₀) or perturbation. At the follow-up assessment 4 patients had granuloma while 15 had normal laryngeal status. Perceptually their voice characteristics resembled those pretherapy independently of the laryngeal findings. The results suggest that reduced hyperfunction and decreased vocal fry may create better circumstances for the healing process at the posterior glottis.     

3D Printing of Capacitive Pressure Sensors with Tuned Wide Detection Range and High Sensitivity Inspired by Bio-Inspired Kapok Structures

Flexible pressure sensors have drawn considerable attention for their potential applications as electronic skins with both sensitivity and pressure response range. Although the introduction of surface microstructures effectively enhances sensitivity, the confined volume of their compressible structures results in a limited pressure response range. To address this issue, a biomimetic kapok structure is proposed and implemented for constructing the dielectric layer of flexible capacitive pressure sensors employing 3D printing technology. The structure is designed with easily deformable concave and rotational structures, enabling continuous deformation under pressure. This design results in a significant expansion of the pressure response range and improvement in sensitivity. Further, the study purposively analyses crucial parameters of the devised structure that affect its compressibility and stability. These include the concave angle θ, height ratio d₁/d₂, rotation angle α, and width k. As a result, the ultimate pressure sensors demonstrate remarkable features such as high sensitivity (≈2.38 kPa⁻¹ in the range of 0–10 kPa), broad detection range (734 kPa), fast response time (23 ms), and outstanding pressure resolution (0.4% at 500 kPa). This study confirms the viability of bionic structures for flexible sensors, and their potential to expand the scope of wearable electronic devices.     

Application of artificial neural network to evaluation of dimensional accuracy of 3D-printed polylactic acid parts

Additive manufacturing (AM) has begun to replace traditional fabrication because of its advantages, such as easy manufacturing of parts with complex geometry, and mass production. The most important limitation of AM is that dimensional accuracy cannot be achieved in all parts. Dimensional accuracy is essential for high reliability, high performance, and useful final products. This study investigates the impact of printing parameters on the dimensional accuracy of samples fabricated through fused deposition modeling (FDM), an additive manufacturing (AM) method utilizing polylactic acid (PLA) material. The experimental design process was performed using Taguchi methodology. ANOVA was used to determine the most important parameter affecting accuracy. Based on experimental studies, the optimal printing parameters for parts are determined as follows: concentric infill pattern, 3 mm wall thickness, 70% infill density, and a layer thickness of 200 μm. Artificial neural network (ANN) was used in the evaluation and prediction of the results. The R-square (R²) performance evaluation criterion was above 95% from the ANN results. This value shows that the results are significant. The data acquired from this study may assist in identifying optimal parameters that contribute to the fabrication of samples with high dimensional accuracy using the FDM method.     

Using a virtual skeleton to increase printability of topology optimized design for industry-class applications

This article broadens the scheme previously developed to associate topology optimization with additive manufacturing through the use of a virtual skeleton, consisting in solving the same physical problem with a discrete approach and then with a continuum one. This procedure for 3D designs is applied to various domain geometries, to demonstrate its pertinence on high-resolution industrial cases. An algorithm searching for the best printing direction, exploring the solid angle, is also described and validated; the surface-shaped presentation of the result allows immediate understanding of the influence of the discrete problem parameters, while its running time is much lower than a unique continuum optimization simulation, which proves the attractiveness of the method. In the three examples studied, the procedure outputs exhibit greater printability than the ones produced by traditional methods in each of the printing direction tested, albeit responsibility is left to the final user to choose his best trade-off. Furthermore, the unprintable zones are readily displayed to be either reworked or supported. Explanations about increase of convergence likelihood on discrete structures despite the geometry complexity of an industrial application are also provided and demonstrated.     

顶空-气相色谱-质谱联用法同时测定紫外光固化胶印油墨中27种溶剂残留

建立了同时测定紫外光固化（UV）胶印油墨中27种溶剂残留（挥发性有机化合物,VOCs）的顶空-气相色谱-质谱联用（HS-GC-MS）法。将UV胶印油墨样品模拟印刷制成一定面积、厚度的试样,在紫外灯下烘烤1 min,经80℃、45 min静态顶空后,通过VOC专用毛细管柱分离和质谱检测,外标法定量。27种VOCs均呈现良好的线性关系,相关系数（R²）均≥0.9950;方法的检出限（LODs,S/N=3）为0.001~0.310 mg/m²,定量限（LOQs,S/N=10）为0.003~0.920 mg/m²;样品的平均加标回收率为80%~108%,相对标准偏差（RSD）<6%（n=6）。该方法制样便捷,灵敏度高,精密度好,准确度高,将其应用于实际UV胶印油墨样品的检测,取得了良好效果。     

丝网印刷柔性电子器件

有机电子器件的主要优势之一是溶液可处理性,这使得可以通过多种印刷方法制备有机电子器件。丝网印刷作为一种十分成熟的印刷方法,被广泛应用于微电子器件的制备。本文主要从丝网印刷的组成、影响丝网印刷精密度的因素以及丝网印刷在场效应晶体管、太阳能电池、有机发光二极管等柔性电子器件制备中的应用分别作以介绍,并对目前丝网印刷在印刷柔性电子器件中存在的困难和挑战作以总结。     

以印染废水为主的城镇污水处理厂锑污染来源特征分析

为研究以印染废水为主的城镇污水处理厂锑污染来源特征,对浙江省嘉善县某污水处理厂及纳管行业进行水体锑（Sb）的采样分析,同时对印染和喷水纺织两大行业的锑污染源进行分析.研究表明,在污水处理厂纳管废水中,印染行业废水占纳管总量的55.2%,排锑量占总量的79.3%,是该污水处理厂锑污染的主要来源;在印染生产过程中,布料中锑的平均流失量为7 mg·kg^-1,平均损失率为13%,污染物锑在退浆、水洗和染色工艺段中的释放量依次为：染色 > 退浆 > 水洗;喷水纺织织造工艺中锑的释放量较少,布料中锑的平均流失量为2.2 mg·kg^-1,平均损失率仅为2.1%;污水处理厂进出水、印染各工段废水和织造废水中,锑主要以Sb（V）形态存在.     

OLED with Hole-Transporting Layer Fabricated by Ink-Jet Printing

we report about the fabrication of organic light-emitting diodes (OLEDs) ink-jet printing a hole-transporting polymer (PF6, poly(9,9-dihexyl-9H-fluorene-2,7-diyl)) on flexible substrate (PET) and performing the other layers through vacuum thermal evaporation. The aim of the work is to employ the ink-jet printing (IJP) technology, familiar as a method for printing on paper, in optoelectronic applications and to determine how the deposition method affects the functional material film properties and hence the ultimate device performances. In this line of work, ink-jet printed polymer films are compared to same spin-coated polymer from the electro-optical point of view: both prepared materials are adopted as HTLs of electroluminescent devices. All manufactured OLEDs are characterized and their behaviours are investigated and analyzed with theoretical models. The results show differences in current density and optical behaviours between the devices fabricated by means of the above mentioned technologies which can be justified in terms of different trap distribution induced by impurity energy levels associated to each process.