Ultrathick SU-8 mold formation and removal, and its application to the fabrication of LIGA-like micromotors with embedded roots

Chien Hung Ho, Kan Ping Chin, Chii Rong Yang, Hsien Ming Wu, Soon Lin Chen

Research output: Contribution to journalArticle

62 Citations (Scopus)


In this study, a novel method to completely remove crosslinked SU-8 without remnants of the resist or destroying the electroplated microstructures was utilized. The LIGA-like fabrication of a side-driven electrostatic micromotor was employed as an example to describe polymerized SU-8 resist removal. Using near-UV light, nickel components of the micromotor were electroplated 160 μm in a 300 μm-thick SU-8 mold. A comparison of various approaches based on a commercial remover was performed during the mold removal process. Experimental results showed that components having 1 μm-deep substructures embedded in the substrate could provide stronger structures to withstand the internal stress due to the photoresist deformation. In addition, when the height of the electroplated structure was below two-thirds of the photoresist mold thickness, the net clamping force on the resist could be effectively reduced to make the removal of SU-8 with heated remover successfully. The rotor and the stator with embedded roots were released cleanly and thereby, assembled to form a high-aspect-ratio micromotor. The technique of SU-8 removal and LIGA-like process presented herein can be applied to the fabrication of other high-powered microactuators.

Original languageEnglish
Pages (from-to)130-138
Number of pages9
JournalSensors and Actuators, A: Physical
Issue number1-2
Publication statusPublished - 2002 Dec 1



  • LIGA-like
  • Microactuator
  • Micromotor
  • Root construction
  • SU-8

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering

Cite this