TBAB hydrate formation and growth in a microdevice under static and dynamic conditions

The natural gas hydrate has become one of the most promising future green energy sources on the earth.The natural gas hydrates mostly exist in the sediments with porous structure, so a solid understanding of the hydrate formation and growth processes in the porous medium is of significance for the exploitation of natural gas hydrate. The micro-packed bed device is one of the efficient microfluidic devices in the engineering field, but it has been rarely used for the hydrate-based research. In this study, a transparent micro-packed bed device filled with glass beads was developed to mimic the porous condition of sediments, and used to in-situ visualize the hydrate formation and growth habits in the pore spaces under both static and dynamic conditions. For the static experiment, two types of hydrate growth patterns in porous medium were observed and identified in the micro-packed bed device, which were the graincoating growth and pore-filling growth. For the dynamic condition, the hydrate formation, growth,distribution habits and hydrate blockage phenomena in the pore spaces were in-situ visually captured.The impacts of flowrate and subcooling on the pressure variation of the micro-packed bed and the duration of the hydrate growth under dynamic flow condition in pores were in-situ monitored and analyzed. The higher flowrate could result in the faster hydrate growth and more severe blockage in pores, but the effect of subcooling condition might be less significant at the high flowrate.

Ultra-Short Pulsed Laser Manufacturing and Surface Processing of Microdevices

Ultra-short laser pulses possess many advantages for materials processing.Ultrafast laser has a significantly low thermal effect on the areas surrounding the focal point;therefore,it is a promising tool for micro-and submicro-sized precision processing.In addition,the nonlinear multiphoton absorption phenomenon of focused ultra-short pulses provides a promising method for the fabrication of various structures on transparent material,such as glass and transparent polymers.A laser direct writing process was applied in the fabrication of high-performance three-dimensional(3D)structured multilayer microsupercapacitors(MSCs)on polymer substrates exhibiting a peak specific capacitance of 42.6 mF·cm^-2 at a current density of 0.1 mA·cm^-12.Furthermore,a flexible smart sensor array on a polymer substrate was fabricated for multi-flavor detection.Different surface treatments such as gold plating,reducedgraphene oxide(rGO)coating,and polyaniline(PANI)coating were accomplished for different measurement units.By applying principal component analysis(PCA),this sensing system showed a promising result for flavor detection.In addition,two-dimensional(2D)periodic metal nanostructures inside 3D glass microfluidic channels were developed by all-femtosecond-laser processing for real-time surfaceenhanced Raman spectroscopy(SERS).The processing mechanisms included laser ablation,laser reduction,and laser-induced surface nano-engineering.These works demonstrate the attractive potential of ultra-short pulsed laser for surface precision manufacturing.

Microfabrication and Performance of Annealed NiTi Shape Memory Thin Films by Sputtering for Microdevice Applications

The microfabrication and performance NiTi shape memory thin films for microdevice applications were studied by microfabrication processes, which were compatible with those of microelectronics fabrication processes. The sputter-deposition conditions, patterning process, and annealing conditions were investigated. The B2 crystal structures of the thin films can be obtained by annealing at 525°C for 30min. The results from x-ray photoemission spectroscopy indicated that the atomic concentration in the surface of the annealed thin films with preferred structures is comparable with those of the as-deposited films.

A deep-reinforcement learning approach for optimizing homogeneous droplet routing in digital microfluidic biochips

Over the past two decades,digital microfluidic biochips have been in much demand for safety-critical and biomedical applications and increasingly important in point-of-care analysis,drug discovery,and immunoassays,among other areas.However,for complex bioassays,finding routes for the transportation of droplets in an electrowetting-on-dielectric digital biochip while maintaining their discreteness is a challenging task.In this study,we propose a deep reinforcement learning-based droplet routing technique for digital microfluidic biochips.The technique is implemented on a distributed architecture to optimize the possible paths for predefined source–target pairs of droplets.The actors of the technique calculate the possible routes of the source–target pairs and store the experience in a replay buffer,and the learner fetches the experiences and updates the routing paths.The proposed algorithm was applied to benchmark suitesⅠand Ⅲ as two different test benches,and it achieved significant improvements over state-of-the-art techniques.

ADI收购宽带GaAs和GaN放大器专业公司OneTree Microdevices打造完整的电缆基础设施解决方案

Analog Devices,Inc.近日宣布收购位于美国加利福尼亚州Santa Rosa的One Tree Microdevices公司。ADI公司是业界领先的混合信号解决方案供应商,提供从数据转换器、时钟到控制/电源调节等电缆接入解决方案。One Tree Microdevices的GaAs和GaN放大器具有业内最佳的线性度、输出功率和效率,收购该公司及产品组合后,使ADI公司能够支持下一代电缆接入网络的整个信号链。该笔交易的财务条款未予披露。

基于B^(*)-树的连续微流控生物芯片流层物理设计方法

作为连续微流控生物芯片设计中的关键步骤,流层物理设计是一个复杂的多目标优化问题,传统方法通常将其分为布局和布线2个阶段。为弥补这2个阶段之间的交互不足,提出了一种基于B^(*)-树的流层物理设计方法,以提高解的质量和求解效率。在布局阶段,采用Memetic算法更高效地搜索解空间。在布线阶段,使用考虑通道顺序的基于协商的算法,同时将布线信息反馈给布局阶段,以调整布局并减少拥挤区域和通道交叉。实验结果表明,与现有算法相比,所提算法在芯片面积、通道总长度以及通道交叉数量等方面取得了更优的效果。

Droplet morphology analysis of drop-on-demand inkjet printing

As an accurate 2D/3D fabrication tool,inkjet printing technology has great potential in preparation of micro electronic devices.The morphology of droplets produced by the inkjet printer has a great impact on the accuracy of deposition.In this study,the drop-on-demand(DoD)inkjet simulation model was established,and the accuracy of the simulation model was verified by corresponding experiments.The simulation result shows that the velocity of the droplet front and tail,as well as the time to disconnect from the nozzle is mainly affected by density(ρ),viscosity(μ)and surface tension(σ)of droplets.When the liquid filament is about to disconnect from the nozzle,the filament length and filament front velocity are found to have a linear correlation withσ/ρμand ln(ρ/(μσ1/2)).

兆声功率密度对同轴兆声辅助喷射电沉积镍的影响

[目的]金属微器件在电沉积过程中往往会产生较大的残余应力,对微器件的尺寸精度、力学性能和良率产生不利影响。[方法]为降低镀层的残余应力,在喷射电沉积镍过程中施加同轴兆声辅助。研究了兆声功率密度对Ni镀层形貌、表面粗糙度、显微硬度和残余应力的影响。[结果]施加同轴兆声辅助后,所得Ni镀层的宏观和微观形貌都有所变差,表面粗糙度略微增大,显微硬度变化不大,但残余应力显著降低。当兆声功率密度为10 W/cm2时,Ni镀层的残余应力最低,比无兆声辅助时所得Ni镀层低了37.75%。[结论]在电沉积过程中施加兆声辅助能够有效降低镀层的残余应力。

基于混合离散粒子群优化的控制模式分配算法

连续微流控生物芯片是生物化学实验自动化、微型化的革命性技术.多路复用器的控制模式分配作为连续微流控生物芯片自动化设计的关键环节之一,是难的NP(Non-deterministic Polynomial)优化问题.现有工作采用粒子群优化算法求解控制模式分配问题存在过早陷入局部最优解、收敛速度慢以及算法稳定性差的缺点.为此,本文提出一种连续微流控生物芯片下基于混合离散粒子群优化的控制模式分配算法.首先,为了加快算法收敛速度及避免过早陷入局部最优解,提出了离散的自适应区域搜索策略.其次,通过基于样例的社会学习机制提高了算法的稳定性.然后,采用等距抽值的方式筛选出自适应区域搜索策略中重要参数的最佳组合,以进一步提高分配方案的质量.最终实验结果表明,所提算法在多路复用器中阀门使用数量上平均优化了19.01%,在算法稳定性上提高了29.18%,且在现实的生化应用中有良好的性能表现.

致病性弧菌检测新技术研究进展

随着人们对水产品需求的增加及致病性弧菌引发的食源性疾病的流行,致病性弧菌对水产养殖业及人类健康造成了巨大威胁,基于此,致病性弧菌检测新技术的开发变得尤为迫切。本文介绍了包括免疫学方法、核酸检测方法、基于生物芯片的检测方法、基于核酸适配体的检测方法、基于肽质量指纹图谱技术的检测方法、基于生物传感器技术的检测方法在内的6项检测技术,分析了其优缺点及其在致病性弧菌中的应用。最后,总结了致病性弧菌检测新技术的研究现状,结合新兴技术指出未来研究方向,为致病性弧菌的快速检测提供参考。

生物芯片技术在食品检验中的应用研究

随着食品安全问题日益受到关注,生物芯片技术作为一种高效、高通量的检测方法,在食品检验中展现出广阔的应用前景。本文综述了生物芯片技术的原理及其在食品检验中的应用,并探讨了其面临的挑战与未来发展前景。

Modeling the Physical Parameters of Solenoids for MEMS Applications

The paper is devoted to study of the electrical parameters of the motion parts of the MEMS such as solenoids. The analytical background is given in order to describe the influence of the electrical field components on the forces, which are result of interaction of the electromagnetic (EM) field components with the parts of motion devices of MEMS. The given analytical formulas open the ability to calculate the self-inductance of the microsolenoids of the different kind, as well as the stored energy of such motion devices, that could be used for the modeling and optimization of parameters of running devices of MEMS such as actuators, sensors etc.

动物源性食品中5类兽药残留的生物芯片试剂盒检测准确性评估

该研究基于微阵列生物芯片试剂盒法评估了动物源性食品中多种兽药残留检测的结果准确性。使用微阵列生物芯片试剂盒法分别对鸡肉、鱼肉、猪肉、乳制品、蜂蜜5种动物源性食品基质中的喹诺酮类、四环素类、氟苯尼考、磺胺类和甲氧苄啶残留量进行测定,考察生物芯片试剂盒法的检出限和定量限,对结果进行准确性评估。结果显示,该方法对5种食品基质中5类兽药残留的检出限和定量限均满足要求,选用鱼肉、蜂蜜和乳制品3种基质加标进行检测,5类兽药残留的加标回收率结果均在72.58%~119.87%之间,RSD均在0.21%~22.49%内,与确证方法进行比较,未出现假阳性或假阴性结果,准确性较好。结果表明,生物芯片试剂盒法检测速度快、成本低、结果准确可靠,在动物源性食品多兽药残留同时筛检中具有广阔应用前景。

不同工艺参数对生物微流控芯片结构合成的影响

本文研究了纳米压印光刻技术在微流控生物芯片制造中替代传统光学光刻技术的可行性。首先探究了V50,V60和V703种不同压印胶胶型及不同转速对压印生物芯片结构的影响,最终选择了浓度较高的V70压印胶在转速为3000 r:·min^(-1)条件下进行旋涂。在电感耦合等离子体刻蚀(inductively coupled plasma,ICP)工艺参数方面,保持其他变量不变,研究了不同刻蚀时间对制备生物芯片结构的影响,最终选择刻蚀时间为900 s。研究结果表明上述条件下所制备的生物芯片微结构具备透光性良好、残余层薄和转移精度高的优点。该方法的工艺简单,具有良好的操作性和可重复性,为生物微流控芯片的制备提供了一种有效且高效的解决方案。同时优化了纳米压印和ICP刻蚀的工艺参数。实现了制备微流控生物芯片时所需的纳米压印设备和刻蚀设备所需的关键参数,为未来微流控芯片的开发和优化提供了实验数据和参考依据。

p16INK4a联合人乳头瘤病毒及液基细胞学检查在宫颈上皮内瘤变临床诊断中的应用

目的分析p16INK4a蛋白、人乳头瘤病毒及液基细胞学检查(LCT)在宫颈癌前病变筛查中的检测效率,为宫颈癌的预防和治疗提供依据。方法分析2019年1月—2020年6月广州市妇女儿童医疗中心的139例住院患者的宫颈上皮细胞p16INK4a染色、人乳头瘤病毒检测及宫颈细胞学检测结果。这些病例包括111例宫颈上皮内瘤变(CIN)患者和28例宫颈炎性疾病患者。比较三种方法单独及联合应用筛查CIN病变的效能。结果在对CIN患者的检测中,p16INK4a、生物微流控芯片和宫颈细胞学检测CIN及以上病变的灵敏度分别为91.89%、94.59%和78.20%,特异度分别为57.14%、17.86%和46.43%,AUC分别为0.75、0.56和0.66。而“p16INK4a+LCT”、“p16INK4a+hrHPV”、“LCT+hrHPV”以及三种方法联合检测的灵敏度分别为96.40%、97.30%、94.59%和99.10%,特异度分别为85.71%、92.86%、89.29%和92.86%,AUC分别为0.91、0.95、0.92和0.96。结论p16INK4a和hrHPV联合检测有助于提高诊断的准确性和早期发现率,从而使得能更早进行干预或治疗。通过这种联合应用,可以更准确地鉴别出低级别和高级别的宫颈上皮内瘤变,为个性化的病患管理提供更多信息。

基于生物芯片技术的生乳中兽药检测方法验证及其应用

为验证生物芯片技术在生乳兽药检测方面的效果并进行推广应用,针对80种常见兽药,采用生物芯片快速检测法对生乳样品进行检测,并同时采用高效液相色谱-串联质谱(high performance liquid chromatographytandem mass spectrometry,HPLC-MS/MS)法确认。结果表明:生物芯片法检出限符合国家标准检出限要求,且部分优于国家标准;该方法线性范围较宽,相关系数均>0.99,线性范围内呈良好的相关性;通过阴性样品加标回收实验,对加入2倍与4倍检出限的标准样品进行测定,加标回收率为70%~130%,变异系数为5%~10%;该方法前处理简单、检测周期短、灵敏度高、通量大,适合大批量样品的快速筛查。利用以上方法对2022—2023年采自上海辖区内的100批次生乳进行检测发现,含有兽药残留的生乳共10批,其中链霉素检出4批(检出值5.86~10.26μg/kg),磺胺吡啶检出3批(检出值1.09~1.42μg/kg),磺胺间二甲氧嘧啶检出2批(检出值1.38~1.46μg/kg),阿维菌素检出1批(检出值1.75μg/kg),经过国标方法确证,以上检出值均远低于国际组织、农业农村部公告或国家标准限量规定。生物芯片法相较于传统的HPLC-MS/MS法具有灵敏度高、线性范围宽和检测速度快等优势,可作为生乳兽药残留快速检测的补充手段,具有较高的应用价值。

基于STM32F4+OV2640的HPV生物芯片阅读装置设计

定期开展HPV分型筛查,对提高妇女健康水平、预防宫颈癌发生的意义重大。为提高检测的自动化水平,减少人工介入和人为误判,设计HPV生物芯片阅读装置的重要性显著。采用STM32F429处理器结合OV2640CMOS传感器,配备M12镜头和可移动30 mm的载物台,可充分发挥可见光显色的TIB-23型HPV生物芯片的筛查优势。结果表明,所设计的HPV生物芯片阅读装置可直接使用HPV芯片杂交仪生化反应托盘,成功阅读四联装TIB-23型HPV生物芯片。该装置对提高HPV分型筛查自动化水平具有重要意义。

Evaluation of specific fecal protein biochips for the diagnosis of colorectal cancer

AIM: To develop and initially test a potential fecal protein biochip for the screening of colorectal cancer (CRC).

Biosensors and Biochips Based on BioMEMS and Nanotechnology

In the past two decades,the biological and medical fields have seen great advances in the development of biosensors and bioehips capable of characterizing and quantifying biomolecules.This lecture is meant to discuss the development and applications of advanced electroanalysis,biophotonics,nanotechnology,MEMS- based biosensors and biochips for biomedical diagnostics and physical performances of athlete.

A novel strategy for in situ maskless synthesis of biochips:Self-driving micro-fluid porous type printing (SMPTP)

A novel maskless technique, self-driving micro-fluid porous type printing （SMPTP）, was reported to in situ synthesize oligonucleotide arrays on glass slide, which has the merits of low cost, high quality and simple craft. In SMPTP for fabricating gene- chips, porous fiber tubes with a number of nanometric or micron channels functioned as ＂active letters＂ and were assembled in designed patterns, which are identical to the distribution of monomers in each layer of the array, and four patterns were needed for each layer. By means of capillarity, the synthesis solution was automatically taken into porous tubes assembled in a printing plate and reached the surface. An oligonucleotide array of 160 features with four different 15-mer probes was in situ synthesized using this technique. The four specific oligonucleotide probes, including the matched and the mismatched by the fluorescent target sequence, gave obviously different hybridization fluorescent signals.