Herein,
we proposed the addition of an inkjet-printed conductive pattern to
paper-based analytical devices (PADs) in order to expand their applications.
An electric conductive pattern was easily, quickly, and inexpensively
fabricated using a commercial inkjet printer. The
addition of a printed electric element will enhance the applications
of PADs without the loss of properties such as cost efficiency, disposability,
and portability. In this study, we applied an inkjet-printed heater
to a piece of paper and investigated its characteristics. The use
of the heater as a valve, concentrator, and heat source for chemical
reactions on PADs was investigated. Previously, these functions were
difficult to realize with PADs. The inkjet-printed heater was used
as a valve and concentrator through evaporation of the working fluid
and solvent, and was also found to be useful for providing heat for
chemical reactions. Thus, the combination of printed electric circuits
and PADs has many potential applications.