Flexible, stretchable and healable electronics

Organic electronics, based on semiconducting and conducting polymers, have been extensively investigated in the past two decades and have found commercial applications in lighting panels, smartphone screens, and TV screens... [ view full abstract ]

Organic electronics, based on semiconducting and conducting polymers, have been extensively investigated in the past two decades and have found commercial applications in lighting panels, smartphone screens, and TV screens using organic light emitting diodes technology. Many other applications are foreseen to reach the commercial maturity in future in areas such as transistors, sensors and photovoltaics.

Organic electronic devices, apart from consumer applications, are paving the path for key applications at the interface between electronics and biology. In such applications, organic polymers are very attractive candidates, due to their distinct properties of mechanical flexibility, self-healing and mixed conduction, i.e the ability to transport both electron/holes and ionic species.

My group investigated the processing conditions leading to high electrical conductivity, long-term stability in aqueous media as well as robust mechanical properties of the conducting polymer poly(3,4-ethylenedioxythiophene) doped with polystyrenesulfonate (PEDOT:PSS), on rigid, flexible and stretchable substrates [1-3]. We have demonstrated that stretchable PEDOT:PSS films can be achieved by adding a fluorosurfactant to the film processing mixture and by pre-stretching the substrate during film deposition. We have achieved patterning of organic materials on a wide range of substrates, using orthogonal lithography, parylene patterning and pattern transfer (Figure 1) [4-5]. Recently we have discovered that PEDOT:PSS films can be rapidly healed with water drops after being damaged with a sharp blade (Figure 2)[6].

My talk will deal with processing, characterization and patterning of conducting polymer films and devices for flexible, stretchable and healable electronics. I will particularly focus on the strategies to achieve films with optimized electrical conductivity and mechanical properties, on unconventional micro patterning on flexible and stretchable substrates, on the different routes to achieve films stretchability and self-healing.

• F. Cicoira et al. APL Mat. 3, 014911, 2015.
• F. Cicoira et al. Appl. Phys. Lett. 107,053303, 2015.
• F. Cicoira, et al. Appl. Phys. Lett., in press (APL17-AR-02492R1).
• F. Cicoira et al. Chem. Mater. 29, 3126-3132, 2017.
• F. Cicoira et al. J. Mater. Chem. C 4, 1382–85, 2016.
• F. Cicoira et al. Adv. Mater., in press (adma201703098).