针对儿童安全及姿态的可穿戴设备设计

针对儿童走失以及儿童坐姿不良这两个问题,设计了一款基于STM32为控制核心的可穿戴设备.设计采用STM32作为主控芯片,采用SIM808模块作为定位、无线网络数据传输、一键求救短信发送模块,将GPS定位数据通过GPRS网络传输至Yeelink云平台存储,通过Yeelink云平台手机或计算机客户端追踪查看历史及实时运动轨迹.采用三轴数字加速度传感器ADXL345和三轴陀螺仪传感器ITG3205作为姿态数据采集芯片,利用四元数算法进行数据融合,得出精确的姿态俯仰角,通过2.4G模块将姿态数据传输至主控模块,用贴片电机进行姿态错误提醒.     

互相关检测法在微弱信号检测中的应用

本文详细分析了如何利用互相关检测法检测出微弱信号,设计了一个基于单片机的微弱信号检测装置.该装置能在噪声源均方根值为1V±0.1V(峰峰值近似为6.6V)的环境下,把峰峰值在200mV-2V范围,频率在500Hz-2000Hz范围内的微弱信号幅值检测出来,检测误差在5%以内.     

Synthesis and liquid crystalline behaviour of substituted (E)-phenyl-4-(phenyldiazenyl) benzoate derivatives and their photo switching ability

Azobenzene derivatives containing phenyl/4-halogen-phenyl 4-{(E)-[4-(pent-4-en-1-yloxy)phenyl]diazenyl}benzoate group with different electronegative substituent (H, F, Cl, Br and I) at other end was synthesised. These azo-based benzoate derivatives have been characterised by FTIR, ¹H-NMR, ¹³C-NMR, elemental analyser, POM and UV-Vis spectroscopy. Photosaturation at 358 nm obtained after 82 s of UV irradiation and the longest thermal back relaxation time of 45 h recorded by UV-Vis. The azo derivative could be possible photolock under UV light, as observed by the improved thermal back relaxation time. The resulting photolockable chain of azobenzene might prove valuable in the development of optical device application. These azobenzene moieties also exhibit liquid crystalline behaviour with respect to the halogen substitution as an electron withdrawing group shows that strong structure property relationship exists among them.     

Laser cutting silicon-glass double layer wafer with laser induced thermal-crack propagation

This study was aimed at introducing the laser induced thermal-crack propagation (LITP) technology to solve the silicon-glass double layer wafer dicing problems in the packaging procedure of silicon-glass device packaged by WLCSP technology, investigating the feasibility of this idea, and studying the crack propagation process of LITP cutting double layer wafer. In this paper, the physical process of the 1064 nm laser beam interact with the double layer wafer during the cutting process was studied theoretically. A mathematical model consists the volumetric heating source and the surface heating source has been established. The temperature and stress distribution was simulated by using finite element method (FEM) analysis software ABAQUS. The extended finite element method (XFEM) was added to the simulation as the supplementary features to simulate the crack propagation process and the crack propagation profile. The silicon-glass double layer wafer cutting verification experiment under typical parameters was conducted by using the 1064 nm semiconductor laser. The crack propagation profile on the fracture surface was examined by optical microscope and explained from the stress distribution and XFEM status. It was concluded that the quality of the finished fracture surface has been greatly improved, and the experiment results were well supported by the numerical simulation results.     

A novel highly flexible,simple, rapid and low-cost fabrication tool for paper-based microfluidic devices (μPADs) using technical drawing pens and in-house formulated aqueous inks

Paper-based microfluidic devices (μPADs) are capable of achieving rapid quantitative measurements of a variety of analytes inexpensively. μPADs rely on patterning hydrophilic-hydrophobic regions on a sheet of paper in order to create capillary channels within impermeable fluidic brakes on the paper. Here, we present a novel, highly flexible and low-cost fabrication method using a desktop digital craft plotter/cutter and technical drawing pens with tip size of 0.5 mm. The pens were used with either commercial black permanent ink for drawing fluidic brakes, or with specialty in-house formulated aqueous inks. With the permanent marker ink it was possible to create barriers on paper rapidly and in a variety of designs in a highly flexible manner. For instance, a design featuring eight reservoirs can be produced within 10 s for each μPAD with a consistent line width of brakes (%RSD < 1.5). Further, we investigated the optimal viscosity range of in-house formulated inks controlled with additions of poly(ethylene glycol). The viscosity was measured by capillary electrophoresis and the optimal viscosity was in the range of ∼3–6 mPa s. A functional test of these μPADs was conducted by the screening of antioxidant activity. Colorimetric measurements of flavonoid, phenolic compounds and DPPH free radical scavenging activity were carried out on μPADs. The results can be detected by the naked eye and simply quantified by using a camera phone and image analysis software. The fabrication method using technical drawing pens provides flexibility in the use of in-house formulated inks, short fabrication time, simplicity and low cost.     

Mixed thread/paper‐based microfluidic chips as a platform for glucose assays

A novel microfluidic thread/paper‐based analytical device (μTPAD) to detect glucose through a colorimetric assay is described. The μTPAD was fabricated from nylon thread trifurcated into three channels terminating at analysis sites comprised of circular zones of chromatography paper, which have previously been spotted with glucose of different concentrations. A solution of glucose oxidase (GOx), horseradish peroxidase (HRP), and potassium iodide (KI) is transported via capillary action to the analysis sites where a yellow‐brown color is observed indicating oxidation of iodide to iodine. The device was then dried, scanned, and analyzed yielding a correlation between yellow intensity and glucose concentrations. Both a flat platform constructed mainly of tape, and a cone platform constructed from tape and polyvinyl chloride, are described. Studies to quantitate glucose in artificial urine showed good correlation using the μTPAD.     

一种新型片上全差分电感的设计

提出了一种新型的片上全差分电感结构。电感采用全对称的几何形状,消除了传统差分电感因跳线引起的失配,提高了差分电感的性能。基于TSMC 0.18 μm RF CMOS工艺,对设计的全差分电感进行流片与测量,结果表明,差分电感两端口之间的失配量比传统差分电感下降了28%。     

通用型数据传输等效接口卡设计

针对测试系统等效器数据传输接口种类繁多,传输频率及传输帧格式有所差异等问题,研制了一种通用型数据传输等效接口卡。将Hotlink接口,RS422接口、RS485接口、CAN接口、LVDS+光纤传输接口等使用频率相对较高的接口集成到一张接口卡上。上位机软件可以通过PXI接口配置数据传输接口、传输频率、传输帧格式等参数。该设计将传统的等效器转变成等效接口卡形式,相对较大的提升了等效器的通用性。通过大量试验证明,该接口卡在不同配置方案下等效的数据,可以进行有效的传输。     

医用高分子材料抗菌表面构建及在医疗器械中应用

医疗器械在介(植)入体内后,在其表面滋生细菌是引发院内感染的最主要原因,给病患带来重大的经济损失,甚至危及生命安全。细菌首先在材料/器械表面粘附,进而形成生物膜,生物被膜一旦形成,会引起细菌持续性感染。为了赋予材料表面抗菌性能,有针对性地进行抗菌表面的构建,其策略主要为:抗细菌粘附策略、杀菌策略、抗细菌粘附-杀菌(抗-杀)结合策略和抗细菌粘附-杀菌转化策略。结合本课题组近年来在抗菌医用高分子材料及医疗器械的研究成果,简单介绍了国内外其抗菌表面构建及在医疗器械中应用的研究进展。