The adherence and subsequent viability of central neural cells (substantia nigra) on silicon wafers with different surface roughness conditions were investigated. Various roughness conditions of the silicon wafer were achieved by etching at different times. The topography was evaluated by AFM. Primary neurons were obtained from Wistar rats. The adherence and subsequent viability of the cells on the wafer were examined by scanning electronic microscopy and fluorescence immunostaining of tyrosine hydroxylase. It is found that the surface roughness affects significantly cell adhesion and viability. Cells can survive for over 5 days on the surface with average roughness in the range 20-70 nm. Such a treatment may provide a new method to make a mild interface of silicon-based electronic devices and neurons as well as other living tissues. (C) 2002 Elsevier Science B.V. All rights reserved.