Performance analysis of valveless micropump with disposable chamber actuated through Amplified Piezo Actuator (APA) for biomedical application

The precise manipulation of fluid through pumping systems has been the technological challenge in microfluidic applications. The biomedical applications call for precise and accurate delivery of fluid through miniaturized pumping systems. This paper presents a novel valveless micropump for biomedical applications operated by the Amplified Piezo Actuator. Integrating the disposable chamber and reusable actuator with the proposed micropump allows the actuator to be reused and eliminates the possibility of infection or contagion. The micropump was fabricated using low-cost polymeric materials like Polymethylmethacrylate (PMMA), Silicone rubber through CNC milling, Laser Cutting, conventional moulding operation. The micropump chamber, nozzle/diffusers, and a bossed diaphragm constituted disposable part and Amplified Piezo Actuator with structural support formed the reusable part of the micropump. The bossed diaphragm of the pump chamber consists of a central cylindrical protrusion to reduce the force of adhesion on the diaphragm and transmit force required for micropump actuation. A theoretical analysis was performed to assess the effect of diaphragm thickness and the bossed region on the effective stiffness of the diaphragm, which in turn influences the deflection achieved. Besides, an analytical approach has been presented to address the effect of adhesive force on the diaphragm surface due to the residual fluid and chamber depth. The experimental characterization of the micropump was carried out to determine the optimal performance parameters with water, fluids mimicking blood plasma, and whole blood. Based on the experimental results, the pumping rate and head developed by the micropump have been significantly affected by factors such as bossed ratio, diaphragm thickness, depth of the micropump chamber, and viscosity of the fluid. The optimum configuration of the micropump cosidered silicone rubber diaphragm with thickness of 0.20 mm having a bossed ratio of 0.33 and a chamber depth of 1.25 mm. With the optimal operating parameters of 150 V sinusoidal input of frequency 5 Hz, the proposed micropump was capable of delivering 7.192 ml/min, 6.108 ml/min, and 5.013 ml/min of water and blood plasma, whole blood mimicking fluid with the maximum backpressure of 294.00 Pa, 226.243 Pa, and 204.048 Pa respectively. The corresponding resolution, i.e., pumping volume/stroke of the micropump was about 23.972 µl, 20.358 µl, and 16.708 µl, respectively.     

φ2mm微马达驱动旋转式微泵

在生物医学、化学液体的流量检测与分析及固态元器件冷却等领域中,均需要流量的精细控制和检测系统。在这类流量精细控制和检测系统中,微小型泵是一个基本元件。作者利用上海交通大学研制成功的、由微细加工工艺制备的、直径为2mm的电磁型微马达作驱动源,并配以电火花加工工艺制备的蜗壳和Ti合金叶轮制成旋转式微泵。微泵的外形尺寸为φ4．5×6．5mm,最大流量可达12ml／min,流量可根据马达转速进行调节。     

GaAs基单片集成InGaP/AlGaAs/InGaAs增强/耗尽型PHEMTs

提出了一种新结构单片集成增强/耗尽型(E/D)InGaP/AlGaAs/InGaAs赝配高电子迁移率晶体管(PHEMTs).外延层材料通过分子束外延技术生长,在室温下,其电子迁移率和二维电子气浓度分别为5410cm2/(V·s)和1.34×1012cm-2.首次提出了普通光学接触曝光分步制作增强与耗尽型的栅技术方法.研制出了单片集成E/D型PHEMTs,获得良好的直流和交流特性,最大饱和漏电流密度分别为300和340mA/mm,跨导为350和300mS/mm,阈值电压为0.2和-0.4V,增强型的fT和fmax为10.3和12.4GHz,耗尽型的fT和fmax为12.8和14.7GHz.增强/耗尽型PHEMTs的栅漏反向击穿电压都为-14V.     

A novel valveless micropump with electrohydrodynamic enhancement for high heat flux cooling

Integrated microchannel cooling systems, with micropumps integrated into microchannels, are an attractive alternative to stand-alone micropumps for liquid-cooled microchannel heat sinks. A new micropump design capable of integration into microchannels and especially suited for electronics cooling is presented. It combines induction electrohydrodynamics (EHD) with a valveless nozzle-diffuser micropump actuated using a vibrating diaphragm. A comprehensive numerical model of the micropump has been developed to study the combined effect of EHD and valveless micropumping. The numerical model has been validated using theoretical and experimental results from the literature. The flow rate achievable from the new micropump is presented and the effect of several key parameters on the micropump performance investigated.     

Efficient miniature s.a.w. convolver

We report the development of a miniature s.a.w. convolver with bandwidth 90 MHz, interaction time 12 ?s, and high efficiency, the output power being ?73 dBm for 1 dBm inputs. The overall size is 80 × 14 × 5 mm.     

无阀微泵泵腔中流体流动的有限元模拟与分析

采用有限元仿真软件ANSYS/FLOTRAN对收缩/扩张型无阀微泵泵腔中流体流动的全过程进行了数值模拟和仿真分析,得到了流体在整个泵腔中的流场构形和流动特性。结果表明,泵腔结构单元的弯道效应与出/入口处流体速度分布的非线性混合将导致腔中的局域涡流现象。通过对3个简单模型的模拟计算,证明了缓冲腔的不同结构对无阀微泵的整流效率有较大影响,是泵腔结构参数优化设计不可忽视的重要环节。     

压电微泵驱动信号及流量影响因素分析

压电微泵的泵出流量由微泵结构、压电振子特性及驱动系统驱动信号的形式决定。在机械结构及材料特性确定的条件下,压电振子的驱动信号决定着微泵输出微流量的可靠性和稳定性。在分析压电微泵驱动基理的基础上,通过Ansys对驱动压电振子有效振动的一、二阶频率进行有限元模拟分析,确定了驱动信号电压幅值、频率对微泵流量的影响。以此为基础搭建压电微泵流量测试实验平台,在相同电压和频率条件下,研究了3种不同脉冲信号（正弦波、三角波、矩形波）对输出流量的影响。通过实验对理论模型进行修正,得到了压电微泵输出流量简化模型。实验验证了所得模型在正弦波、三角波、矩形波3种不同波形驱动下最大误差不超过4%,控制范围内可靠性在99.0%以上。综合比较可知,方波脉冲信号为压电微泵最佳驱动信号。     

电磁驱动柔性振动膜无阀微泵

提出了一种新型微泵设计方案和制作工艺，将电磁驱动器与大振幅振动膜相结合，得到流量大、易于控制的新型微泵。该微泵结构简单，由硅橡胶(聚二甲基硅氧烷PDMS橡胶)振动膜和无阀泵泵体组成，将硅加工工艺和非硅加工工艺(电镀)相结合。采用电镀和硅橡胶加工方法将振动膜直接制作在一个硅片上；用电镀和体硅加工工艺将驱动线圈和无阀泵泵体制作在另一块硅片上，然后将两个硅片键合在一起。对该微泵的性能特点正进行着更深入的研究。     

半非平面单块激光器快速频率调谐的实验研究

在半导体激光器抽运的Nd∶YAG晶体半非平面单块固体环形激光器上 ,采用粘贴压电陶瓷 (PZT)的方法实现了快速激光频率调谐。对尺寸为 13mm× 14mm× 3mm的单块激光器粘贴了厚度为 0 5mm压电陶瓷 ,并观测两台单块激光器之间的拍频信号。当调制频率小于 10 0kHz时 ,对压电陶瓷施加峰值为 5V的正弦调制信号 ,可观测到大于 10MHz的马鞍形展宽拍频信号 ,对应的PZT调谐系数大于 1MHz/V。当调制信号频率过高时 ,例如频率大于 10 0kHz,拍频信号变得非常不稳定 ,说明激光频率产生了明显的漂移 ,且拍频信号展宽的形状也发生了变化 ,拍频信号的中心部分由凹陷变为凸起。实验观测到的调制响应带宽约为 10 0kHz。     

昆明物理研究所大面积水平推舟液相外延碲镉汞薄膜技术进展

报道了近年来昆明物理研究所在富碲水平推舟液相外延碲镉汞外延薄膜制备技术方面的进展。2019年以来,突破了?120 mm碲锌镉晶体定向生长技术,使碲锌镉衬底沉积相和夹杂相密度≤5×103 cm－2,位错腐蚀坑密度（EPD）≤4.0×104 cm－2,?120 mm（111）晶圆衬底的Zn组份分布极差≤0.36%。基于碲锌镉衬底技术的进步,液相外延碲镉汞薄膜的最大生长尺寸达到了70 mm×75 mm,薄膜位错腐蚀坑密度均值为5×104 cm－2,X射线双晶回摆曲线半峰宽（DCRC-FWHM）≤35 arcsec,部分可控制到25 arcsec以下;50 mm×60 mm尺寸长波碲镉汞薄膜的厚度极差≤±1.25 μm,室温截止波长极差≤±0.1 μm,中波碲镉汞薄膜相应指标分别为≤±1 μm、≤±0.05 μm。材料技术的进展促进了制冷型碲镉汞探测器产能提升和成本的降低,也支撑了高性能长波/甚长波探测器、高工作温度（HOT）探测器以及2048×2048、4096×4096等甚高分辨率高性能探测器的研制。     

压电膜片的优化设计及在微泵中的应用

压电驱动是微机械系统(MEMS)微执行器最有发展前途的驱动方式之一。该文采用ANSYS有限元软件对压电膜片结构参数和在微执行器上的装配方法进行了优化设计,得到PZT/Si,PZT/Cu压电膜片结构的优化数据,将其应用于有阀微泵的研制。经测试,微泵压电驱动效果与仿真结果一致,微泵背压可达836 Pa,流量达1.4 mL/min。     

一种四通道X波段放大组件的研制

为适应微波电路高性能、高可靠、多功能、小型化的发展趋势,介绍了一种四通道一体化设计的具有限幅功能的x波段放大组件。该组件利用微波混合集成电路工艺和芯片微组装工艺实现,阐述了其小型化设计方法。测试结果表明：该组件尺寸为52mm×56mm×14mm,电性能达到指标要求。     

大画幅等待式转镜分幅相机结构设计

采用共轴理论和控制离焦相结合的方法,设计了大画幅等待式转镜分幅相机,该相机的画幅尺寸达到了30mm×18mm,同时还具备了相对孔径大和分辨率高的特点,对底片的相对孔径为空间方向1/15和扫描方向1/35,动态目视分辨率达到了35lp/mm,总画幅数80幅,摄影频率1×104～5×105 frame/s。采用2×105 frame/s的拍摄频率对某爆轰过程进行了试验记录,得到了高分辨率的图像。结果表明:相机的画幅尺寸大、空间分辨率高,适用于冲击、爆轰和弹体姿态等试验过程和目标的拍摄。     

一种硅四层键合的高对称电容式加速度传感器

提出了一种利用体微机械加工技术制作的硅四层键合高对称电容式加速度传感器.采用硅/硅直接键合技术实现中间对称梁质量块结构的制作,然后采用硼硅玻璃软化键合方法完成上、下电极的键合.在完成整体结构圆片级真空封装的同时,通过引线腔结构方便地实现了中间电极的引线.传感器芯片大小为6.8mm×5.6mm×1.68mm,其中敏感质量块尺寸为3.2mm×3.2mm×0.84mm.对封装的传感器性能进行了初步测试,结果表明制作的传感器漏率小于0.1×10-9cm3/s,灵敏度约为6pF/g,品质因子为35,谐振频率为489Hz.     

A multichannel thermal bubble-actuated impedance flow cytometer with on-chip TIA based on CMOS-MEMS

Electrochemical impedance spectroscopy (EIS) flow cytometry offers the advantages of speed, affordability, and portability in cell analysis and cytometry applications. However, the integration challenges of microfluidic and EIS read-out circuits hinder the downsizing of cytometry devices. To address this, we developed a thermal-bubble-driven impedance flow cytometric application-specific integrated circuit (ASIC). The thermal-bubble micropump avoids external piping and equipment, enabling high-throughput designs. With a total of 36 cell counting channels, each measuring 884 × 220 μm², the chip significantly enhances the throughput of flow cytometers. Each cell counting channel incorporates a differential trans-impedance amplifier (TIA) to amplify weak biosensing signals. By eliminating the parasitic parameters created at the complementary metal-oxide-semiconductor transistor (CMOS)-micro-electromechanical systems (MEMS) interface, the counting accuracy can be increased. The on-chip TIA can adjust feedback resistance from 5 to 60 kΩ to accommodate solutions with different impedances. The chip effectively classifies particles of varying sizes, demonstrated by the average peak voltages of 0.0529 and 0.4510 mV for 7 and 14 μm polystyrene beads, respectively. Moreover, the counting accuracies of the chip for polystyrene beads and MSTO-211H cells are both greater than 97.6%. The chip exhibits potential for impedance flow cytometer at low cost, high-throughput, and miniaturization for the application of point-of-care diagnostics.     

小型长波红外光栅光谱仪光学设计

光学系统是光谱仪微小型化的关键,光学设计的质量将直接影响微小型光谱仪的性能.针对长波红外光谱探测的具体应用,对比国内外各种方案,分析其优劣后提出一种基于交叉非对称切尔尼-特纳(Czerny-Turner)结构的小型光栅光谱仪.首先根据光谱仪基本原理和光学设计理论,分析系统的光谱分辨率、像差以及探测灵敏度.然后以小型化、低成本、要求的光谱范围和分辨率为具体设计目标,对系统进行优化设计.最后在光学软件Zemax中进行模拟和优化.设计结果表明:该系统的光谱范围为8～14μm,光谱分辨率优于80nm,光学系统尺寸约为100mm×75mn×45mm,满足小型化要求.同时采用扫描光栅配合单通道探测器的方式降低成本.     

激光材料的杂质检测系统

报道一台检测激光玻璃中白金颗粒的系统。它是一台由计算机控制的扫描系统,被检测材料尺寸为600mm×300mm×40mm,扫描范围为600mm×300mm,激光能量密度大于20J/cm2,已成功地检测出白金颗粒,小于10μm的白金颗粒也可测到     

Resonantly driven piezoelectric micropump: Fabrication of a micropump having high power density

As a fluid power source for practical micromachines using fluid power such as in-pipe mobile micromachines, micropumps having high power density are required. In this paper, a piezoelectric micropump using resonance drive is fabricated with the size of φ 9×10 mm. It basically consists of a bellows as a flexible pump chamber, a piezoelectric actuator for oscillating the bellows, and cantilever type of two check valves. An additional mass is attached to the free end of the piezoelectric actuator to enlarge amplitude of the displacement at resonant point. Firstly, through basic experiments using tap water as a working fluid, frequency characteristics and load characteristics of the pressure-dependent flow rate are experimentally investigated with various additional masses and valve thicknesses for stable and high performance. Next, for pumping of fluids having much higher viscosity than tap water, some improvements such as redesign of check valves and an application of a boost pressure are performed. Through basic experiments on pump performances using silicone oil, the effectiveness of those improvements is verified. As a result, the feasibility of the resonantly driven piezoelectric micropump is confirmed.     

铌酸锂晶体结构对电场传感器灵敏度影响分析

铌酸锂晶体光学电场传感器为全介质结构,具有宽带宽、对被测电场干扰小的优点,但其灵敏度较低。因此,分析了晶体几何尺寸对传感器灵敏度的影响机理,得出通过增加沿外加电场方向的晶体尺寸同时减少晶体横截面上沿外加电场垂直方向的晶体尺寸来提高传感器的灵敏度。使用COMSOL仿真分析了铌酸锂晶体不同厚度、宽度、长度对晶体内部电场强度的影响,得出晶体厚度从15 mm减小到3 mm和宽度从3 mm增加到22 mm时,晶体内部电场强度分别提高约5.1倍和12.3倍;晶体长度从15 mm变化到55 mm时,晶体内部的电场强度变化仅约为5%。设计并研制出晶体尺寸分别为3 mm×3 mm×42.2 mm (x×y×z),3 mm×6 mm×42.2 mm (x×y×z),6 mm×6 mm×42.2 mm(x×y×z)的三只铌酸锂晶体电场传感器,并搭建工频电场测试平台,测试得出三只电场传感器的灵敏度分别为0.243 mV/(kV·m^-1)、0.758 mV/(kV·m^-1)、0.150 mV/(kV·m^-1)。当晶体厚度和长度一定且晶体宽度从3 ...     

基于GaN HEMT工艺的高功率宽带6 bit数字移相器

基于GaN HEMT工艺研制了一款8～12.5 GHz宽带6 bit数字移相器.通过采用优化的宽带拓扑和集总元件,以及在片上集成GaN并行驱动器,提高了移相精度,缩小了芯片的尺寸,减少了控制端数量.测试结果表明,在8～12.5 GHz频带内,全部64个移相状态下,插入损耗小于11 dB,输入回波损耗小于-14 dB,输出回波损耗小于-16 dB,移相均方根误差小于1.8°,幅度变化均方根误差小于0.5 dB.在8 GHz频率下,1 dB压缩点输入功率高达33 dBm.芯片尺寸为5.05 mm×2.00 mm×0.08 mm.