Sacrificial layer technique for releasing metallized multilayer SU-8 devices

Anand Tatikonda, Ville P. Jokinen, Hanno Evard, Sami Franssila*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

3 Citations (Scopus)
120 Downloads (Pure)


The low fabrication cost of SU-8-based devices has opened the fields of point-of-care devices (POC), μTAS and Lab-on-Chip technologies, which call for cheap and disposable devices. Often this translates to free-standing, suspended devices and a reusable carrier wafer. This necessitates a sacrificial layer to release the devices from the substrates. Both inorganic (metals and oxides) and organic materials (polymers) have been used as sacrificial materials, but they fall short for fabrication and releasing multilayer SU-8 devices. We propose photoresist AZ 15nXT (MicroChemicals GmbH, Ulm, Germany) to be used as a sacrificial layer. AZ 15nXT is stable during SU-8 processing, making it suitable for fabricating free-standing multilayer devices. We show two methods for cross-linking AZ 15nXT for stable sacrificial layers and three routes for sacrificial release of the multilayer SU-8 devices. We demonstrate the capability of our release processes by fabrication of a three-layer free-standing microfluidic electrospray ionization (ESI) chip and a free-standing multilayer device with electrodes in a microchannel.

Original languageEnglish
Article number673
Issue number12
Publication statusPublished - 19 Dec 2018
MoE publication typeA1 Journal article-refereed


  • AZ 15nXT
  • Free standing
  • Microchips
  • Microfabrication
  • Microfluidics
  • Multi layered chips
  • Sacrificial release
  • SU-8


Dive into the research topics of 'Sacrificial layer technique for releasing metallized multilayer SU-8 devices'. Together they form a unique fingerprint.

Cite this