LCD Microstereolithography of Photosensitive Resin with Functional Particles
Terutake Hayashi* , Yasuhiro Takaya* , and Dongkeon Lee**
* Department of Mechanical Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
** Advanced Manufacturing Research Institute (AMRI), National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1 Namiki, Tsukuba, Ibaraki 305-8564, Japan
A novel microstereolithography (µ-STL) process has been developed in order to fabricate microparts using photosensitive resin with functional particles containing microparticles or nanoparticles. The reduction in the surplus growth, which is caused by light scattered by the filler particles in the photosensitive resin, is accomplished by using grey-scale exposure with a liquid crystal display (LCD) mask. A fabrication process that uses photosensitive resins reinforced with ceramic nanoparticles is developed. Micro bevel gears with a diameter of 1.6 mm and a tooth width of 180 µ m are fabricated. Next, the fabrication process of the electrically conductive parts is examined using a photosensitive resin that contains microsized silver particle as electrically conductive fillers. Micro-resistance patterns are fabricated to evaluate the electrical conductivity of the micro part. Annealing is then conducted for the removal of the photosensitive resin at a temperature of 350±10°C for 1 h. At a filler content of 50 wt%, the electrical resistance is as small as 3×105 W Ω•cm. Using a four-level grey-scale mask, 100 microelectrodes are fabricated simultaneously.