**3. 3-D fabrication method**

This section describes the fabrication of 3-D structures using SR lithography. In this article, two fabrication methods are described in detail: the plain-pattern to cross-section transfer (PCT) technique and the pixels exposure technique. When the PCT technique is used, it is possible to fabricate a microneedle array structure (Khumpuang et al., 2006). When the pixels exposure technique is used, it is possible to fabricate a 3-D structure with a complex surface, such as an asymmetrical structure.
