UV Laser Photo-Polymerization of Elastic 2D/3D Structures Using Photo-Curable PDMS (Polydimethylsiloxane)

2D/3D structuring of UV curable polydimethylsiloxane (PDMS) was developed using UV laser direct writing. In this technique, commercially available UV curable PDMS was locally polymerized to fabricate 1D and 2D single layer structures, as well as 3D multi-layer structures with sufficient stability in process resolutions. The tightly focused UV laser beam was scanned by an x-y galvanometric mirror scanner on the UV curable PDMS layer coated on the glass substrate, so that 18 mu m of process resolution in X-Y plane was obtained. At the relevant wavelength of 355 nm, the absorbance of UV curable PDMS was 0.131, which is sufficient absorbance for a photo-chemical reaction induced by the UV laser used in this study. In addition, UV curable PDMS has a deep penetration depth, longer than 3 mm, which enabled the fabrication of a structure with an aspect ratio of 3 in a single layer. Furthermore, the fabricated structure demonstrated mechanical strength to emphasize its elasticity.