Wrinkle-Enabled Flexible Electrodes via Direct Printing for Deformable Electrochemical Sensing

The development of flexible electrodes is crucial for advancing wearable and stretchable electronic technologies. Wrinkled microstructures on elastomeric substrates have been widely explored to mitigate mechanical strain and enhance durability; however, conventional fabrication approaches typically require prestraining, thermal expansion, or multistep processing that lack design flexibility and spatial control. Here, we present a direct printing strategy that enables solvent-driven, localized wrinkling on polydimethylsiloxane (PDMS) substrates using triethylene glycol monoethyl ether (TGME)-based conductive inks. Owing to its high boiling point and strong swelling capacity, TGME induces robust wrinkle formation during printing without the need for additional curing or encapsulation. The resulting electrodes maintain stable conductivity under severe bending and demonstrate superior mechanical resilience compared to non-wrinkled counterparts. Furthermore, we demonstrate the integration of wrinkled electrodes into wearable electrochemical sensors capable of detecting hydrogen peroxide as a representative biomarker. These wrinkle-enabled sensors exhibit reproducible electrochemical responses under repeated bending and cycling, highlighting their potential for next-generation and mechanically adaptive wearable biosensing platforms.