新型涂层聚氯代对二甲苯的性能及其应用研究

用真空沉积技术制备了聚氯代对二甲苯(Parylene C)涂膜,考核了聚氯代对二甲苯涂膜与特种材料的附着力及涂膜的拉伸性能、耐化学介质性能、表面抗静电性能,并对具有复杂形状的工件表面进行均匀涂覆作了探索研究。结果表明聚氯代对二甲苯涂膜具有优异的综合性能,可以在复杂形状工件表面形成均匀涂膜,对被涂覆材料起到很好的保护作用。     

Annealing for the improvement of the capabilities of parylene C as electret

Parylene C is a polymer elaborated by chemical vapor deposition and is particularly useful for the coating of deformed structures. New-generation soft energy harvesting electrostatic generators can be of complex shape. These generators need electret material in order for them to function. It could thus be interesting to incorporate parylene C in this device. However, this polymer suffers from bad retention of trapped charges after corona discharge and a poor thermal stability of these charges. In this work, parylene C polymers were subjected to specific annealing before corona charging. This induces strong changes in the crystallinity of the material. Atomic force microscopy and X-ray diffraction quantified the crystalline nature of parylene C following the annealing temperature. Surface potential decay of corona-charged parylene C demonstrated that annealing to about 150°C is beneficial for the trapping of charges for a long time (analysis over 12 days). At the same time, thermal stability of the electret parylene C is achieved up to 100°C. Spherulites with a specific area close to the surface of the polymer could explain such performances due to their influence on the distribution of traps. Dielectric analysis does not confirm that the decay of surface charges is correlated to the dynamics of polymer chains, although the moving of chains probably influences the flowing of these charges. In sum, annealed parylene C appears to be a new interesting candidate for electret-based electrostatic generators. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46908.     

Synergistic Roll‐to‐Roll Transfer and Doping of CVD‐Graphene Using Parylene for Ambient‐Stable and Ultra‐Lightweight Photovoltaics

A roll‐to‐roll (R2R) transfer technique is employed to improve the electrical properties of transferred graphene on flexible substrates using parylene as an interfacial layer. A layer of parylene is deposited on graphene/copper (Cu) foils grown by chemical vapor deposition and are laminated onto ethylene vinyl acetate (EVA)/poly(ethylene terephthalate). Then, the samples are delaminated from the Cu using an electrochemical transfer process, resulting in flexible and conductive substrates with sheet resistances of below 300 Ω sq^?1, which is significantly better (fourfold) than the sample transferred by R2R without parylene (1200 Ω sq^?1). The characterization results indicate that parylene C and D dope graphene due to the presence of chlorine atoms in their structure, resulting in higher carrier density and thus lower sheet resistance. Density functional theory calculations reveal that the binding energy between parylene and graphene is stronger than that of EVA and graphene, which may lead to less tear in graphene during the R2R transfer. Finally, organic solar cells are fabricated on the ultrathin and flexible parylene/graphene substrates and an ultra‐lightweight device is achieved with a power conversion efficiency of 5.86%. Additionally, the device shows a high power per weight of 6.46 W g^?1 with superior air stability.     

基于MEMS技术可植入微压力传感器的检测电路设计（英文）

为实现体内压力（如：血压、颅内压等）的实时监测,采用微机电系统（MEMS）技术制造出植入式微压力传感器.由于它是电容式传感器,在信号读取系统中,首先通过集成电路CAV414将电容信号转换为电压信号.通过理论计算和实际试验测试,微压力传感器初始电容值为15 pF.CAV414检测范围是10 pF~2 nF,检测精度为电容初始值的5%,因此在该系统中可检测到的电容最小变化量为0.75 pF,其输出电压范围为0~5 V,该电压信号可以直接作为模拟/数字转换器（ADC）的输入信号.选用ADC0809实现模拟信号向数字信号的转换.ADC0809为一款8通道8位模数转换器,通过FPGA实现对ADC0809的驱动控制.ADC0809的8位输出信号直接作为数字信号的输入,在本文试验中数字信号处理通过FPGA编程实现.     

Stability of fluorinated parylenes to oxygen reactive-ion etching under aluminum,aluminum oxide,and tantalum nitride overlayers

The fluorine stability of two parylenes, aliphatic-fluorinated AF-4 (α, α, α′, α′ poly(p-tetrafluoroxylylene) and aromatic-fluorinated VT-4 (2, 3, 5, 6 poly(p-tetrafluoroxylylene), were investigated underneath Al, Al₂O₃, and TaN_X overlayers with and without exposure to oxygen reactive-ion etching (RIE). No fluorine diffusion was observed for Al films deposited onto the as-received parylenes. However, after oxygen RIE, x-ray photoelectron spectroscopy (XPS) depth profiling detected fluorine diffusion throughout Al and to a lesser extent Al₂O₃ but in contrast to Ta_2.67N. Metal-fluoride bonding was evident at the metal/parylene interface for all the overlayers after the parylene was exposed to oxygen RIE and annealed.     

Parylene敷形涂层

Parylene是一种性能优异的高聚合物材料,它能涂敷到各种形状的表面,例如金属、玻璃、纸张、树脂、塑料、陶瓷等。简述了Parylene涂层的性能,对Parylene涂层的沉积过程、沉积设备和Parylene涂层的应用领域进行了论述,并对Parylene涂层的性能与环氧树脂、有机硅树脂、聚氨酯涂层的性能进行了比较。     

基于CVD技术的异步多通路电针灸针的研究

针灸治疗是中医治疗疾病的一种有效方法,随着现代针灸的新科技与经络穴位的结合,传统的毫针逐渐发展到了脉冲电针、电热针等.该文提出一种异步多通路刺激的电针灸针.基于传统的毫针,通过微加工工艺在一根毫针针体上加工出若干个刺激电极,微加工工艺包括溅射金属层及化学气相沉积(CVD)绝缘层聚对二甲苯.聚对二甲苯作为电极间的绝缘材料,具有无针孔涂覆、更低的液气渗透率、良好的生物相容性、透明性和柔韧性、以及较好的机械强度.通过连接电针灸仪,在一根针上即可实现异步多条电流通路的刺激.     

New approach to chemical functionalization of poly(2‐chloroxylylene) thin films

3‐(8‐Octenyl)thiophene was used for successful preparation of functionalized poly‐(2‐chloro‐xylylene) (PCX) layers in the course of CVD process. The set of spectral methods used has allowed us to conclude that such modification is based on the chemical reaction of double bonds with xylylene radicals. Functionalized films were used for further chemical transformation in the course of polycondensation of 3‐octylthiophene. Resulted samples are bilayer films and polythiophene layer is chemically connected with PCX one. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011