This research reports a micro-fabrication method for plastic microscale structures. Although a stepped shape, such as a cantilever, can be fabricated by micro electro mechanical systems (MEMS) deep etching technology, its disadvantages include the complicated fabrication process and its limited utilization with silicon only. Therefore, in this study, with an aim to address the aforementioned problems, we have realized the fabrication of a multi-stage structure using just a general photolithography process with high versatility. Specifically, it can be manufactured using only SU-8 resist and AZ resist, which are often used in the MEMS process. The AZ resist has the advantage of dissolving in the developer of the SU-8 resist, whether exposed or non-exposed. Thus, the sacrificial layer of AZ resist can be implemented with the SU-8 developer, thereby eliminating the need for dangerous chemicals such as hydrofluoric acid, which is used to etch silicon oxide. Herein, we have derived the optimum conditions by considering in advance the thickness of the AZ resist, the time taken to be etched in SU-8, and the desired features. Based on these optimum processing conditions, the structure could be suspended only in the region where the hole array was patterned. Although methods of using AZ resist as a sacrificial layer and floating SU-8 have been reported, in this study, both floating and fixed structures could be simultaneously fabricated by photolithography only. Accordingly, we successfully manufactured a gear structure and a MEMS sensor, both of which have floating and fixed structures. The above structures are made of highly transparent SU-8 on a glass substrate; hence, they are easily observable with a microscope. The reason for the widespread use of polydimethylsiloxane micro-channels is that they are transparent materials that can be observed under a microscope and fabricated by simple photolithography of the SU-8 resist, enabling non-microfabrication specialists to enter this field. These findings have the potential to form the foundation for developing new biochemical tests, such as actuators and sensors driven under a microscope.

这项研究报告了一种塑料微尺度结构的微制造方法。尽管可以通过微机电系统（MEMS）深蚀刻技术制造悬臂等阶梯形状，但其缺点包括制造工艺复杂且仅使用硅有限。因此，在本研究中，为了解决上述问题，我们仅使用通用的光刻工艺就实现了多级结构的制造。具体来说，它可以仅使用 MEMS 工艺中经常使用的 SU-8 抗蚀剂和 AZ 抗蚀剂制造。AZ 抗蚀剂的优点是可以溶解在 SU-8 抗蚀剂的显影剂中，无论是曝光的还是未曝光的。因此，AZ抗蚀剂的牺牲层可以用SU-8显影剂实现，从而无需使用危险化学品，例如用于蚀刻氧化硅的氢氟酸。在此，我们通过预先考虑 AZ 抗蚀剂的厚度、在 SU-8 中蚀刻所需的时间以及所需的特征来推导出最佳条件。基于这些最佳加工条件，该结构可以仅悬浮在孔阵列图案化的区域中。尽管已经报道了使用 AZ 抗蚀剂作为牺牲层和浮动 SU-8 的方法，但在本研究中，浮动和固定结构只能通过光刻同时制造。因此，我们成功地制造了齿轮结构和MEMS传感器，它们都具有浮动和固定结构。上述结构由玻璃基板上的高透明SU-8制成；因此，它们很容易用显微镜观察到。聚二甲基硅氧烷微通道广泛使用的原因是它们是透明材料，可以在显微镜下观察，并通过 SU-8 抗蚀剂的简单光刻制造，使非微细加工专家能够进入该领域。这些发现有可能为开发新的生化测试奠定基础，例如在显微镜下驱动的致动器和传感器。