Preparation of 2-directional gradient surfaces for the analysis of cell-surface interactions

Lauren R. Clements, Yit Lung Khung, Helmut Thissen, Nicolas H. Voelcker

Research output: Chapter in Book/Report/Conference proceedingConference PaperOtherpeer-review

5 Citations (Scopus)


The ability to evaluate and control the cellular response to substrate materials is the key to a wide range of biomedical applications ranging from diagnostic tools to regenerative medicine. Gradient surfaces provide a simple and fast method for investigating optimal surface conditions for cellular responses such as attachment and growth. By using two orthogonal gradients on the same substrate, a large space of possible combinations can be screened simultaneously. Here, we have investigated the combination of a porous silicon (pSi) based topography gradient with a plasma polymer based thickness gradient. pSi was laterally anodised on a 1.5 × 2.5cm2 silicon surface using hydrofluoric acid to form a pore size gradient along a single direction. The resulting pSi was characterised by SEM and AFM and pore sizes ranging from macro to mesoporous were found along the surface. Plasma polymerisation was used to form a thickness gradient orthogonal to the porous silicon gradient. Here, allylamine was chosen as the monomer and a mask placed over the substrate was used to achieve the thickness gradient. The analysis of this chemistry based gradient was carried out using profilometry and XPS. It is expected that orthogonal gradient substrates will be used increasingly for the in vitro screening of materials used in biomedical applications.

Original languageEnglish
Title of host publicationBioMEMS and Nanotechnology III
Publication statusPublished - 12 May 2008
Externally publishedYes
EventBioMEMS and Nanotechnology III 2007 - Canberra, Australia
Duration: 5 Dec 20077 Dec 2007

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


ConferenceBioMEMS and Nanotechnology III 2007


  • Plasma polymerisation
  • Porous silicon
  • Surface modification
  • Two-directional gradients

Cite this