Air plasma assisting microcontact deprinting and printing for gold thin film and PDMS patterns.

In this paper， we present a simple method to fabricate gold film patterns and PDMS patterns by air plasma assisting microcontact deprinting and printing transfer approaches. Chemical gold plating is employed instead of conventional metal evaporation or sputtering to obtain perfect gold film both on flat and topographic PDMS chips， and complicated SAM precoating is replaced by simple air plasma treatment to activate both the surface of gold film and PDMS. In this way， large area patterns of conductive gold film and PDMS patterns could be easily obtained on the elastomeric PDMS substrate. Both the chemical plating gold film and transferred gold film were of good electrochemical properties and similar hydrophilicity with smooth and conductive surface， which made it potentially useful in microfluidic devices and electronics. The gold transfer mechanism is discussed in detail. For typical applications， a cell patterning chip based on the gold pattern was developed to imply the interfacial property， and dielectrophoresis control of live cells was carried out with the patterned gold as interdigital electrodes to show the conductivity.