微加工

Abstract(#br)Here we present an elastomeric force sensitive resistor (FSR) made from a porous matrix of polydimethylsiloxane (PDMS) filled with carbon black. The fabrication process is based on the use of a low cost sacrificial sugar cube scaffold which leads to a highly porous and compressible material. By filling this porous matrix with carbon black we can achieve typical resistance changes from 20 kΩ to 100 Ω for an applied 95% compressive strain. This material is suitable for a wide variety of sensing applications which include tactile artificial skin for robotics and solvent detection.

Abstract(#br)A three-dimensional (3D) structure comprising precisely defined micro-architecture and surface micro-textures, designed to present specific physical cues to cells and tissues, may provide an efficient scaffold in a variety of tissue engineering and regenerative medicine applications. We report a fabrication technique based on microfabrication and soft lithography that permits for the development of 3D scaffolds with both precisely engineered architecture and tailored surface topography.

Abstract(#br)In this article we demonstrate the effect of mechanical compression on the behavior of cultured neural stem cells using a microelectromechanical system platform. Polydimethylsiloxane (PDMS)-based stretchable substrates were used on a neurosphere (NS) assay to investigate the role of mechanical forces on the formation of radial glial processes and neuronal migration. To induce mechanical compression on NS, the PDMS culturing substrate was patterned with micron-sized wells. NS were cultured on the prestretched device.

Abstract(#br)This paper discusses microfabrication process for benzophenone doped polydimethylsiloxane (PDMS) using laser lithography. KrF excimer laser of 248\u003cce:hsp sp=\"0.25\"/\u003enm with 20\u003cce:hsp sp=\"0.25\"/\u003ens pulse width at repetition rate of 1\u003cce:hsp sp=\"0.25\"/\u003eHz was used for microfabrication of undoped and benzophenone doped PDMS. The doped-PDMS shows sensitivity below 365\u003cce:hsp sp=\"0.25\"/\u003enm, permitting processing under ambient light.

Abstract(#br)Resolution targets composed of bilayer polydimethylsiloxane (PDMS) devices with buried polyethylene glycol (PEG) channels have been fabricated using traditional photolithographic and micromolding techniques to develop resolution targets that mimic pharmaceutical materials. Raman chemical images of the resulting PEG-in-PDMS devices composed of varying parallel line widths were investigated by imaging the PEG lines through a thin overlayer of PDMS.

Abstract(#br)This paper describes a simple method for the fabrication of screen-printed based electrodes for amperometric detection on microchip electrophoresis (ME) devices. The procedure developed is quite simple and does not require expensive instrumentation or sophisticated protocols commonly employed on the production of amperometric sensors, such as photolithography or sputtering steps. The electrodes were fabricated through manual deposition of home-made conductive carbon ink over patterned acrylic substrate.

摘要 多孔膜广泛应用于细胞器分选、渗透细胞生长基质、等离子体过滤等微纳米流体领域。由于薄膜基材的机械稳定性差，传统的硅制备方法不适用于微孔膜。其他的离子轨道刻蚀技术仅限于制备孔径不均匀的随机分布、随机取向的孔隙。 本课题采用旋铸和软光刻相结合的方法，利用质子束流( PBW )技术制备了高透过率微孔膜。该方法利用聚焦2 MeV质子，在硅片上涂复SU-8层，由少µm大小的六边形高密度柱组成的光刻图形。开发完成后，采用聚对二甲苯( Parylene ) -C缓释剂薄膜和聚二甲基硅氧烷( PDMS )旋涂的方法对柱体进行均匀涂复。为了便于拆模，开发了一种基于激光切割密封圈的特殊工艺。该方法成功地实现了20μm厚PDMS膜从模具中分离出高密度微孔，无破裂和损伤。

Nonspherical monodisperse polydimethylsiloxane (PDMS) microparticles were fabricated by lithography and ultraviolet ozone (UVO) treatment for self-assembly of periodic structures. PDMS solution was poured into photoresist molds on glass substrates, whereupon it was cured at 80°C. After irradiating ultraviolet to the surface of the PDMS, remaining thin PDMS films on the molds were eliminated using ultrasonic waves.

The emphasis of this paper lies in the fabrication of a three-layer polydimethylsiloxane chip for micro liquid sample operation. In this paper, the microchannels with a rectangular control layer cross section are fabricated based on a dry-film negative photoresist mold, while the microchannels with a rounded liquid layer cross section are fabricated by a positive photoresist reflow mold. The relationships between temperature and the time of reflow and the arc level of the liquid layer mold are discussed.

激光加工是传统微细加工技术的廉价、快速替代，具有制造复杂三维、层次结构的能力。在对极端热流冷却装置进行快速原型和快速设计研究的同时显得尤为重要。困扰利用激光微细加工制造商用器件的一个主要问题是切削过程中碎屑的形成以及加工过程后难以有效去除这些碎屑。对于硅基片，这种杂物会通过阻止均匀共形接触而干扰周围的组分，并在与其他基片的键合过程中产生问题。本研究深入探究了基于激光微机械加工制造这种复杂三维流形微冷却器结构时所面临的挑战和克服这些挑战的方法。具体而言，本文总结了Nd / YVO4紫外( UV )激光刻蚀硅样品过程中可用于完全去除碎片的几种后处理技术，详细阐述了每种方法的优缺点。一种被发现特别有希望实现几乎完全清除碎片的非常光滑表面的方法是使用聚二甲基硅氧烷( PDMS )作为高刚性防护涂层。在此过程中，还开发了一种从硅表面剥离PDMS的新技术。本文的研究结果对基片表面光滑洁净的微加工行业具有重要的参考价值，将显著改善紫外激光用于商业应用和研究环境中微结构的制造工艺。