A dry process for production of microfluidic devices based on the lamination of laser-printed polyester films.
A new microfabrication process based on a xerographic process is described. A laser printer is used to selectively deposit toner on a polyester film, which is subsequently laminated against another polyester film. The toner layer binds the two polyester films and allows the blank regions to become channels for microfluidics. These software-outlined channels are approximately 6 microm deep. Approximately twice this depth is obtained by laminating two printed films. The resulting devices were not significantly damaged after 24 h of exposure to aqueous solutions of H3PO4, NaOH, methanol, acetonitrile, or sodium dodecyl sulfate. Electric tests with an impedance analyzer and microchannels filled with KCl solution demonstrated that (1) wide channels suffer from deformation of the top and bottom walls due to the lamination of the polyester films and (2) the toner walls are somewhat porous. Although these drawbacks limit the maximum width of a channel and the minimum distance between two channels, the process is an attractive option to other expensive, laborious, and time-consuming methods for microchannels fabrication. The process has been used to implement devices for electrospray tip and capillary electrophoresis with contactless conductivity detection.
Departamento de Químicas Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, CEP 05508-900, São Paulo, SP, Brazil. claudemi@iq.usp.br
Claudimir Lucio
CL
do Lago
Heron Dominguez Torres
HD
da Silva
Carlos Antonio
CA
Neves
José Geraldo Alves
JG
Brito-Neto
José Alberto Fracassi
JA
da Silva