Surface Modification of PDMS Thin Films for Printing Conductive Ink

Polydimethylsiloxane (PDMS) thin films are an attractive substrate for flexible and stretchable electronics. In this work, the surface modification of PDMS is performed with low pressure plasma under Ar+O
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environment to print flexible conductor pattern directly on the PDMS surface. The treatment increases the wettability of the PDMS surface, which is confirmed with water contact angle measurements. It reduces the contact angle from 117.3° to about 18.4° immediately after the treatment. The printed silver patterns on the treated PDMS films demonstrate good adhesion after soak, ultrasonic and blow tests. They also show strong mechanical stability and great electric conductivity under bending and releasing. This simple surface modification technique can overcome the printability issue of conductors on hydrophobic PDMS substrates.