Seal Formation in Silicon Planar Patch-Clamp Microstructures

Author

Curtis, John C. ; Baldwin, Keith ; Dworak, Bradley J. ; Stevenson, J. Tom M ; Delivopoulos, Evangelos ; MacLeod, Nikki K. ; Murray, Alan F.

Author_Institution

Centre for Integrative Physiol., Univ. of Edinburgh, Edinburgh

Volume

17

Issue

4

fYear

2008

Firstpage

974

Lastpage

983

Abstract

This paper presents a microfabricated planar patch-clamp electrode design and looks at the impact of several physical characteristics on seal formation. The device consists of a patch aperture, 1.5-2.5 mum in diameter and 7-12 mum in depth, with a reverse-side deep-etched 80-mum well. The patch aperture was coated with either thermal oxide or plasma-enhanced chemical vapor deposited (PECVD) SiO₂. Some of the thermal oxide devices were converted into protruding nozzle structures, and some were boron-doped. Seal formation was tested with cultured N2a neuroblastoma cells. The PECVD oxide devices produced an average seal resistance of 34 MOmega(n = 24), and the thermal oxide devices produced an average seal resistance of 96 MOmega(n = 59). Seal resistance was found to positively correlate with patch aperture depth. Whole-cell recordings were obtained from 14% of cells tested with the thermal oxide devices, including a single recording where a gigaohm seal was obtained.

Keywords

bioMEMS; biomedical electrodes; cancer; cellular biophysics; microelectrodes; micromachining; nozzles; plasma CVD coatings; silicon compounds; tumours; cultured N2a neuroblastoma cells; depth 7 mum to 12 mum; gigaohm seal; microfabrication; nozzle structures; patch aperture; physical characteristics; planar patch-clamp electrode design; plasma-enhanced chemical vapor deposition; reverse-side deep-etched well; seal formation; silicon planar patch-clamp microstructures; size 1.5 mum to 2.5 mum; thermal oxide devices; whole-cell recordings; Atomic force microscopy; N2a cells; biomedical transducers; electrophysiology; microelectrodes; microelectromechanical devices; micromachining; silicon;

fLanguage

English

Journal_Title

Microelectromechanical Systems, Journal of

Publisher

ieee

ISSN

1057-7157

Type

jour

DOI

10.1109/JMEMS.2008.924270

Filename

4542977