玻璃基底上的蛋白质微接触压印图型化

研究了一种将胶原Ⅰ型蛋白通过微接触压印技术图型化于玻璃基底表面的方法.采用标准光刻工艺制备印章母版,并运用反应离子刻蚀设备对印章表面进行氧等离子体处理,以期改善印章表面亲水性能.将涂敷了胶原Ⅰ型蛋白,并经返潮处理的印章以50 g/cm^2大小的力与玻璃表面接触10 s,得到蛋白质微图型.结果表明,采用反应离子刻蚀技术能显著改善聚二甲基硅氧烷（PDMS）印章表面的亲水性.表面亲水性得到改善的PDMS印章,在经过湿盒返潮后,再进行微接触压印得到的蛋白质微图型其质量得到显著提高.     

印章特性和印刷压力对微接触印刷工艺的影响

微接触印刷（μCP）是一种能在微纳米尺度上完成表面图案化的技术,主要特点是高效和低成本．研究了μCP过程中印章机械特性和印刷压力对形成的微图案质量的影响．为了进一步分析聚二甲基硅氧烷（PDMS）制作的印章特性,浇注了5种配比的PDMS试样,并进行了单轴拉伸和压缩试验,获得了其应力应变关系．制作了3种配比的表面线型图案印章,实施微接触印刷使其印刷压强在1kPa～1MPa．通过图形化分析对最终的微接触印刷质量进行评估．实验结果表明：最优的压强区间为20～200kPa．较小的压力将会产生印章与基底的间隙,而较大的压力将会导致印章的严重变形．由于质量比为20：1的PDMS印章的弹性模量最小,其在中等压力下的微接触印刷质量最好,而较硬的印章可有效地抵抗印刷中产生的变形．     

基于微接触印刷法的PbS微图案的制备

以聚二甲基硅氧(PDMS)弹性体为印模,十八烷基三氯硅烷(OTS)为"墨水",采用微接触印刷法分别在平整的玻璃基片表面和弯曲的玻璃棒表面进行印刷操作,将印刷后的基片浸入到PbS化学浴液中沉积得到微图案化的PbS薄膜.交叉印刷和光学显微观察结果表明,所沉积的PbS微图案边界清晰规整,并且PbS会选择性沉积在基片表面没有被OTS覆盖的区域.     

Microcontact Printing: Limitations and Achievements

Microcontact printing (µCP) offers a simple and low‐cost surface patterning methodology with high versatility and sub‐micrometer accuracy. The process has undergone a spectacular evolution since its invention, improving its capability to form sub‐100 nm SAM patterns of various polar and apolar materials and biomolecules over macroscopic areas. Diverse development lines of µCP are discussed in this work detailing various printing strategies. New printing schemes with improved stamp materials render µCP a reproducible surface‐patterning technique with an increased pattern resolution. New stamp materials and PDMS surface‐treatment methods allow the use of polar molecules as inks. Flat elastomeric surfaces and low‐diffusive inks push the feature sizes to the nanometer range. Chemical and supramolecular interactions between the ink and the substrate increase the applicability of the µCP process.     

印章结构对微接触印刷制备导电网格的影响

为了在PET基底上制备精细的透明网格状导电图案, 本工作利用微接触印刷高精度的优势, 分别采用线条结构和网格结构的印章转印银纳米粒子导电油墨, 分析了其转印过程, 并讨论了印章结构对网格图案性能的影响。结果表明: 采用线条结构的印章可真实还原印章设计尺寸, 避免了线条的扩展, 有利于提高网格图案的透光率; 同时, 在交叉处墨层较厚可提高导电性。而采用网格结构印章可一次转移快速获得网格图案, 但由于印章网格上相邻线条之间液桥的形成会使图案线宽增加, 降低其透光率; 采用间距较大的印章可使液桥断裂, 得到边缘光滑的网格图案, 但间距增大导致单位面积导电路径减少, 降低其导电性。总之, 采用线条结构印章有利于获得性能较好的网格图案, 但两次转移过程相对复杂, 需用时间较长。     

Microcontact printing and selective surface dewetting for large area electronic applications

A universal microstructuring approach was developed, which facilitates the patterning of surfaces by a combination of microcontact printing (mCP) and selective surface dewetting/wetting. Self-assembled monolayers (SAMs) were patterned on glass or silicon substrates by μCP. The regions coated by the SAMs turn hydrophobic, whereas the uncoated regions stay hydrophilic. Such functionalized surfaces facilitate selective deposition of polymers or resists. Polymethyl methacrylate and prepolymer polyurethane were selectively deposited on the hydrophilic regions of the substrate. The hydrophobic regions of the substrate stay uncoated. Subsequently, the resist was used to lift-off metallic microstructures in order to realize micro coils and electrodes for radio frequency information tags. The printed electrodes were used to define drain and source contacts of organic thin film transistors. The device characteristic of the organic transistors will be presented.     

Microcontact printing of indium metal using salt solution “ink”

Poly(dimethlysiloxane) stamps were made from Si masters fabricated using photolithography and anisotropic etching. GaCl₃ and In(NO₃)₃ were microcontact printed onto Si substrates, creating arrays of micron size metal salt deposits. The In(NO₃)₃ deposits were further processed by annealing in an N₂ :H₂ (9:1) forming gas environment at 600 °C which converted the deposits into In metal. The ability to inexpensively pattern metal arrays on semiconductor surfaces has implications for ohmic contacts and, with additional processing, arrays of semiconductor crystallites for optoelectronic applications.     

Microcontact Printing onto Oxide‐Free Silicon via Highly Reactive Acid Fluoride‐Functionalized Monolayers

This work describes a new route for patterning organic monolayers on oxide‐free silicon by microcontact printing (µCP) on a preformed, reactive, acid‐fluoride‐terminated monolayer. This indirect printing approach is fast and easily preserves the oxide‐free and well‐defined monolayer–silicon interface, which is the most important property for potential applications in biosensing and molecular electronics. Water‐contact‐angle measurements, ellipsometry, attenuated total reflection infrared spectroscopy, and X‐ray photoelectron spectroscopy (XPS) demonstrate the formation of the initial acid‐fluoride‐terminated monolayers without upside‐down attachment. Subsequent printing for twenty seconds with an N‐hexadecylamine‐inked poly(dimethylsiloxane) stamp results in well‐defined 5‐µm N‐hexadecylamide dots, as evidenced by atomic force microscopy and scanning electron microscopy. Printing with a flat stamp allows investigation of the efficiency of amide formation by µCP and water‐contact‐angle measurements, ellipsometry, and XPS reveal the quantitative conversion of the acid fluoride groups to the corresponding amide within twenty seconds. The absence of silicon oxide, even after immersion in water for 16 h, demonstrates that the oxide‐free monolayer–silicon interface is easily preserved by this patterning route. Finally, it is shown by fluorescence microscopy that complex biomolecules, like functionalized oligo‐DNA, can also be immobilized on the oxide‐free silicon surface via µCP.