Howard Riley L, Bernardi Francesca, Leff Matthew, Abele Emma, Allbritton Nancy L, Harris Daniel M
Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Department of Mathematical Sciences, Worcester Polytechnic Institute, Worcester, MA 01609, USA.
Micromachines (Basel). 2021 Nov 4;12(11):1360. doi: 10.3390/mi12111360.
Liquid lithography represents a robust technique for fabricating three-dimensional (3D) microstructures on a two-dimensional template. Silanization of a surface is often a key step in the liquid lithography process and is used to alter the surface energy of the substrate and, consequently, the shape of the 3D microfeatures produced. In this work, we present a passive technique that allows for the generation of silane gradients along the length of a substrate. The technique relies on a secondary diffusion chamber with a single opening, leading to a directional introduction of silane to the substrate via passive diffusion. The secondary chamber geometry influences the deposited gradient, which is shown to be well captured by Monte Carlo simulations that incorporate the passive diffusion and grafting processes. The technique ultimately allows the user to generate a range of substrate wettabilities on a single chip, enhancing throughput for organ-on-a-chip applications by mimicking the spatial variability of tissue topographies present in vivo.
液体光刻是一种在二维模板上制造三维（3D）微结构的强大技术。表面硅烷化通常是液体光刻过程中的关键步骤，用于改变基底的表面能，进而改变所产生的3D微特征的形状。在这项工作中，我们提出了一种被动技术，该技术能够沿着基底长度生成硅烷梯度。该技术依赖于一个具有单个开口的二次扩散室，通过被动扩散将硅烷定向引入到基底。二次室的几何形状会影响沉积梯度，蒙特卡罗模拟结合被动扩散和接枝过程能够很好地捕捉到这一梯度。该技术最终使用户能够在单个芯片上产生一系列基底润湿性，通过模拟体内组织地形的空间变异性，提高了芯片上器官应用的通量。
