Substrates for flexible electronics: A practical investigation on the electrical, film flexibility, optical, temperature, and solvent resistance properties

TLDR

Designing and developing flexible electronics requires a thorough investigation of the substrates available for device fabrication. The study highlights issues and proposes solutions to improve substrate response. The authors evaluate PET, HS‑PET, PEN, ITO/PEN, ITO/PET, rigid ITO/glass, FTO/glass, stainless steel, and titanium foils by testing optical properties, mechanical flexibility under tensile and compressive bending (with and without PEDOT:PSS), solvent resistance, temperature stability, and UV irradiation. The extracted results and thresholds reveal limitations and windows of opportunity that aid designers in selecting manufacturing processes and final applications for flexible optoelectronics under everyday operation. © 2011 Wiley Periodicals, Inc., J Polym Sci Part B: Polym Phys, 2011.

Abstract

Abstract Designing and developing flexible electronics requires a thorough investigation of the substrates available for the fabrication of devices. Here, we present a practical study on a variety of significant substrates: polyethylene terephthalate (PET), its heat‐stabilized (HS) derivative, HS‐PET, and polyethylene naphthalate (PEN) plastic insulating films; indium tin oxide (ITO)‐coated ITO/PEN and ITO/PET transparent conducting films; rigid ITO/glass and FTO/glass substrates; stainless steel and titanium foils. We put the substrates through a range of tests these actually undergo during device fabrication to determine their optical, mechanical flexibility (under different types of tensile and compressive stress bending with and without a PEDOT:PSS conducting polymer layer), solvent resistance, stability to temperature treatment (conductivity and deformation), and to UV irradiation. We highlight issues and propose solutions to improve substrate response. The results and thresholds extracted reveal limitations and windows of opportunity useful for the designer of flexible optoelectronics in determining manufacturing processes and the final applications under everyday operation. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011