An underexposure photolithography method was developed to fabricate self-detached polymer micropore membranes with uniform pore size, shape, and arrangement. The key to this technique is to control and adjust the gradient of exposure dose projected into the film of photoresist. This new approach abandons sacrificial layers used in previous techniques. Negative SU-8 was chosen as an example photoresist to demonstrate its feasibility. Membranes with specially tailored sizes and shapes of micropores could be produced on diverse substrates. The coefficient of variation of pore size was only 1%, much lower than that for conventional microporous membranes. Moreover, due to self-detaching without a sacrificial layer, the membranes were flat and free of residual stress and deformation. This novel photolithographic approach opened a new avenue to manufacture high-quality membranes that could broaden the applications of microparticle filtration, separation, and sorting.

中文翻译：

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通过曝光不足光刻制造具有明确孔径、形状和分布的自分离膜

开发了一种曝光不足的光刻方法来制造具有均匀孔径、形状和排列的自分离聚合物微孔膜。该技术的关键是控制和调整投射到光刻胶膜中的曝光剂量梯度。这种新方法放弃了先前技术中使用的牺牲层。选择负 SU-8 作为示例光刻胶以证明其可行性。可以在不同的基材上生产具有特别定制的微孔尺寸和形状的膜。孔径变异系数仅为1%，远低于传统微孔膜。此外，由于没有牺牲层的自分离，膜是平坦的，没有残余应力和变形。