The nanostructure and viscoelastic property of PEDOT:PSS was modified by blending an excess amount of a nonvolatile surfactant plasticizer, Triton X-100, so that it can be repeatedly stretched and molded in a manner similar to rubber play dough. A nonionic surfactant was added to a commercial aqueous PEDOT:PSS solution. The concentration of the PEDOT:PSS in the commercial product was found to be 1.3 wt%. The concentration of the surfactant varied from 0.5 to 5 wt%. To prepare thin films, the mixture solutions were spin-coated on various substrates, and the thickness was controlled by repeating the spin-coating after drying the previously coated fi lm at 70°C for 5 min. A 1 μm thick PEDOT:PSS layer was coated on a PDMS substrate and used as a stretchable circuit for the deformability test with LED chips. After planting the LED chips in the PEDOT:PSS circuits, a commercial elastomer product was coated on the circuit to encapsulate and fix the LEDs. The PEDOT:PSS film was pressed with an intagliated PDMS stamp by hand. The resulting pattern was an array of square dots protruding from a PEDOT:PSS bottom layer. When the thickness was increased to 900 μm, the conductance of the PEDOT:PSS pattern was higher than that of the Au pattern. Those thick patterns also showed negligible change in conductivity during repeated stretching cycles, and the relaxation of the stress was governed by the contraction force of the substrate.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering