AFM

Abstract(#br)In effort to investigate the influence of the micro/nano-patterning or surface texturing on the nanotribological properties of patterned surfaces, the patterned polydimethylsiloxane (PDMS) surfaces with pillars were fabricated by replica molding technique. The surface morphologies of patterned PDMS surfaces with varying pillar sizes and spacing between pillars were characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). The AFM/FFM was used to acquire the friction force images of micro/nano-patterned surfaces using a colloidal probe.

Abstract(#br)The elastic moduli of polystyrene (PS), polymethylmethacrylate (PMMA) and polydimethylsiloxane (PDMS) films were evaluated using an Atomic Force Microscope (AFM) with a steel micro-spherical probe tip. The elastic moduli of the polymeric films were determined with respect to indentation depth using the Hertz and Johnson-Kendall-Roberts (JKR) models. The measured elastic moduli of PS, PMMA and PDMS were determined to be 2.6 GPa, 0.74 GPa, and 4 MPa at indentation depths of 1.7 nm, 4 nm, and 120 nm, respectively.

Abstract(#br)In this study, nanomechanical properties of a variety of polymeric materials was investigated by means of AFM. In particular, selecting different AFM probes, poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS) bulk samples, sol–gel hybrid thin films and hydrated hyaluronic acid hydrogels were indented in air to determine the elastic modulus. The force–distance curves and the indentation data were found to be greatly affected by the cantilever stiffness and by tip geometry.

Abstract(#br)Zeta potential of PDMS-liquid interface is an important parameter for generating electroosmotic flow in a PDMS microchannel. In this paper, the zeta potentials of a PDMS slab in contacting with electrolyte solutions were evaluated with an atomic force microscope (AFM). As a colloidal probe of the AFM approaches to the surface of a PDMS slab in an electrolyte solution, a force curve is obtained and used to calculate the zeta potential of the PDMS.

用于制作片上器官( OOC )应用的微流控芯片的表面修饰往往是一个耗时的过程，涉及芯片清洗、紫外( UV )曝光、蒸汽灭菌等。本文报道了一种简单、快速、经济的方法，利用标准生物安全柜内的紫外光，在微流控芯片上一步实现儿茶酚胺材料的光引发聚合和图形化。聚二甲基硅氧烷( PDMS )微流控器件中填充多巴胺和去甲肾上腺素单体，然后在紫外光照射下引发材料的聚合，为OOC的应用创造了一个高度可行的表面。我们考察了这些紫外光引发的表面涂层用于制造3种不同的OOCs的性能，微流控芯片通过3种不同的方式进行键合和修饰：1 )常规的氧等离子体键合微流控芯片填充单体溶液，然后暴露在紫外光下对表面进行修饰(等离子体键合，聚合物包复)；2 )流体层和玻璃基底均暴露在紫外光下对功能层进行包复，同时允许黏合蛋白将这2块结合在一起(紫外光键合，聚合物包复)；3 )通过掩膜将紫外光投射到聚二甲基硅氧烷( PDMS )基底上，形成流体壁微流控通道(投影包复)。3种技术中在紫外光照射聚合物涂层表面接种的Cath . a . differential ( CAD )细胞表现出明显的高细胞活力、细胞黏附、增殖、基因表达，与未涂层PDMS相比保留了功能性。UV引发的表面改性技术使用了一种极简的方法，使用较少的设备和现有的基础设施，如生物安全柜，来创建一个功能性的OOC。