FABRICATION PROCESS OF HIGH-ASPECT-RATIO ELASTIC AND SU-8 STRUCTURES FOR PIEZOELECTRIC MOTOR APPLICATIONS

We report on recent advances in micro fabrication technology using mic romolding and high aspect ratio structuring of photopolymer. The direc t application is the realization of components for millimeter-size, ul trasonic piezoelectric motors. A new fabrication process using a thick epoxy-based material (SU-8) and the electroplating of nickel is demon strated. Photopolymer structures have also been realized and released using a positive tone resist as sacrificial layer. The main advantages over past fabrication methods are better design flexibility, simplici ty of the fabrication process, the capability to combine metallic mate rials (Ni) with polymeric materials ( SU-8), and the use of positive t one resist as a sacrificial layer. (C) 1998 Elsevier Science S.A. All rights reserved.