Page 384 - Organic Electronics in Sensors and Biotechnology

CHAPTER 10

Electrophoretically

Deposited Polymers

for Organic

Electronics

Chetna Dhand and B. D. Malhotra
Department of Science and Technology Centre on Biomolecular
Electronics National Physical Laboratory, New Delhi, India

10.1 Introduction
The phenomenon of electrophoretic deposition (EPD) has been
known since 1808 when an electric field-induced movement of clay
particles in water was observed by the Russian scientist Ruess. How-
ever, the first practical use of the electrophoretic technique occurred
in 1933 when thoria particles deposited on a platinum cathode were
used as an emitter for electron tube application. This process is being
industrially used for applying coatings to metal fabricated products. 1
EPD is a colloidal process wherein the materials are shaped directly
from a colloidal suspension upon application of a DC electric field.
All colloid particles that can carry a charge can be used in EPD. This
includes materials such as polymers, pigments, dyes, ceramics, and
metals. With regard to the technological application, the potential of
EPD as a material processing technique is increasingly being recog-
nized by scientists and technologists. In addition to its conventional
applications in the fabrication of wear-resistant and antioxidant
ceramic coatings, it is used for fabrication of films for advanced
microelectronic devices and solid oxide fuel cells, as well as in the
development of novel composites or bioactive coatings for medical
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