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Stretching‐Induced Growth of PEDOT‐Rich Cores: A New Mechanism for Strain‐Dependent Resistivity Change in PEDOT:PSS Films
Author(s) -
Lee YooYong,
Lee JiHoon,
Cho JuYoung,
Kim NaRae,
Nam DaeHyun,
Choi InSuk,
Nam Ki Tae,
Joo YoungChang
Publication year - 2013
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201203670
Subject(s) - pedot:pss , materials science , piezoresistive effect , electrical resistivity and conductivity , stretchable electronics , composite material , ultimate tensile strength , conductivity , modulus , nanotechnology , polymer , electronics , chemistry , electrical engineering , engineering
It remains a fundamental challenge in the development of stretchable electronics to understand how mechanical strain changes the electrical properties of materials. Although the piezoresistive behavior of poly(3,4‐ethylene‐ dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been observed, its intrinsic origin is not yet fully understood because there are many extrinsic contributing factors and an experimental platform with which to assess such behavior has not been established. Here, systematic analysis shows that the matching Poisson's ratio and elastic modulus between PEDOT:PSS films and their underlying substrates is important in decoupling the factors that affect the material's piezoresistivity, allowing for tunable resistivity. Based on such a fundamental understanding, the conductivity of PEDOT:PSS can be controlled to be invariant and decrease as a function of applied tensile stress. Furthermore, a linear response of the resistivity with respect to mechanical strains of up to 60%, which has never before been realized, is shown. The irreversible conductivity enhancement is primarily caused by the coalescence‐induced growth of conductive PEDOT‐rich cores.