Evaluation of negative photo-patternable PDMS for the encapsulation of neural electrodes

Author

Delivopoulos, E. ; Minev, I.R. ; Lacour, S.P.

Author_Institution

Eng. Dept., Univ. of Cambridge, Cambridge, UK

fYear

2011

fDate

April 27 2011-May 1 2011

Firstpage

490

Lastpage

494

Abstract

This communication examines the suitability of a photo-patternable polydimethylsiloxane (PP-PDMS) elastomer as an insulating material for implantable microelectrodes. PP-PDMS is produced by mixing a photoinitiator (2-hydroxy-2-methylpropiophenone) with the PDMS base and curing agent. Subsequent exposure to UV radiation and development of the elastomeric “photo-resist” allows for the definition of well-defined openings within the PP-PDMS film. The dielectric constants of PP-PDMS and PDMS are similar (ε ≈ 2.6, f <;1MHz). Gold film microelectrodes patterned on glass or a PDMS substrate are encapsulated with PP-PDMS, while recording sites as small as 10⁴ μm² can be obtained in the PP-PDMS layer. The cytotoxicity of the PP-PDMS was preliminary tested in vitro by culturing 3T3 fibroblasts in PP-PDMS extracts. No adverse effects were observed in cultures exposed to PP-PDMS films initially leached in isopropanol solvent for 48h.

Keywords

biomedical electrodes; cellular biophysics; elastomers; gold; microelectrodes; neurophysiology; permittivity; photoresists; prosthetics; toxicology; 2-hydroxy-2-methylpropiophenone; 3T3 fibroblasts culture; Au; UV radiation exposure; curing agent; cytotoxicity; dielectric constants; implantable microelectrodes; negative photopatternable PDMS elastomer; neural electrode encapsulation; photoinitiator; photoresist; polydimethylsiloxane; Electrodes; Encapsulation; Fibroblasts; Gold; Impedance; Media;

fLanguage

English

Publisher

ieee

Conference_Titel

Neural Engineering (NER), 2011 5th International IEEE/EMBS Conference on

Conference_Location

Cancun

ISSN

1948-3546

Print_ISBN

978-1-4244-4140-2

Type

conf

DOI

10.1109/NER.2011.5910593

Filename

5910593