An electromagnetic actuator using a cylindrical coil created with 3D x-ray lithography and metallization techniques

The demand for microactuators is increasing recently. The key technology to realizing practical microactuators is microfabrication process. In the production of microminiature components, the technologies for processing high-aspect-ratio structures are essential. As one of these technologies, the LIGA (German acronym for Lithographite, Galvanoformung and Abformung) process is widely known. Our laboratory researches the LIGA process to three-dimensional microfabrication and established the cylindrical-microcoil production process. In this paper, we have fabricated the cylindrical-microcoil for to the solenoidal electromagnetic type microactuator. We designed and analyzed microactuators, and fabricated and evaluated microactuator coils produced by the combination of three-dimensional x-ray lithography and level copper plating. We succeeded in creating threaded groove-shaped structures (10 mu m line width, 20 mu m pitch, and aspect ratio of 5) on the surface of an acrylic pipe by means of three-dimensional X-ray lithography. The processing technology enables the formation of thin-wire coil lines whose current paths feature a large allowable current-carrying capacity, enabling the production of miniature, high-output microactuators.