Intrinsically Stretchable Integrated Passive Matrix Electrochromic Display Using PEDOT:PSS Ionic Liquid Composite

Abstract

The low power consumption of electrochromism makes it widely used in actively shaded windows and mirrors, while flexible versions are attractive for use in wearable devices. Initial demonstration of stretchable electrochromic elements promises good conformability to complex surfaces. Here, fully integrated intrinsically stretchable electrochromic devices are demonstrated as single elements and 3 × 3 displays. Conductive and electrochromic ionic liquid-doped poly(3,4-ethylenedioxythiophene) polystyrene sulfonate is combined with poly(vinyl alcohol)-based electrolyte to form complete cells. A transmission change of 15% is demonstrated, along with a reflectance change of 25% for opaque reflective devices, with <7 s switching time, even under 30% strain. Stability under both electrochemical and mechanical strain cycling is demonstrated. A passive matrix display exhibits addressability and low cross-talk under strain. Comparable optical performance to flexible electrochromics and higher deformability provide attractive qualities for use in wearable, biometric monitoring, and robotic skin devices.

Flexible and Stretchable Light-Emitting Diodes and Photodetectors for Human-Centric Optoelectronics

“…For instance, Preston et al reported on the fabrication of intrinsically stretchable electrochromic display based on PEDOT:PSS/ionic liquid composite TEs. 327 An ionic liquid of 1-butyl-3-methylimidazolium octyl sulfate was strategically adopted to enhance both the conductivity and stretchability of the TE, of which the reported values were 288 S/cm and 176%, respectively. In another work by Ma et al, the conductivity and stretchability of PEDOT:PSS-based TEs were modified by combining PEDOT:PSS with poly(1-vinyl-3ethylimidazolium dicyanamide) ionogel.…”

“…The focus of research has been on enhancing the electrical conductivity and stretchability of the TEs by incorporating ionic liquids, ionic salts, or surfactants as plasticizers. For instance, Preston et al reported on the fabrication of intrinsically stretchable electrochromic display based on PEDOT:PSS/ionic liquid composite TEs . An ionic liquid of 1-butyl-3-methylimidazolium octyl sulfate was strategically adopted to enhance both the conductivity and stretchability of the TE, of which the reported values were 288 S/cm and 176%, respectively.…”

Recent advances in the construction and application of stretchable PEDOT smart electronic membranes

“…The intensity of their blue channel rapidly increases with ∼1.2 V DC input within 20 s, allowing quantification of color evolution under stretching conditions. Preston et al 230 demonstrated a fully integrated stretchable EC of PEDOT:PSS and the 1-butyl-3-methylimidazolium octyl sulfate (BMIM OSU) ionic liquid composite film, achieving maximum color change at ±1.6 V (colorless to colored). The device exhibits excellent light modulation performance, fast color switching speed, and good cycling stability, maintaining its optical modulation after 500 electrochemical cycles at 30% strain.…”

Boosting the Performance of PEDOT:PSS Based Electronics Via Ionic Liquids

“…[16][17][18] Consequently, since its chemical synthesis as a stable aqueous dispersion by the Heraeus company in 1988, PE-DOT:PSS has found extensive application in energy conversion and storage, sensors, and bioelectronics. [19,20] Nonetheless, untreated films of PEDOT:PSS exhibit subpar electrical conductivity (less than 1 S cm −1 ) because of the absence of clearly defined and uninterrupted charge transport channels caused by its core (PEDOT)/shell (PSS) configuration, the surplus of insulating PSS presenting in commercial suspensions (with a PE-DOT/PSS ratio of ≈1:2.5), and the disorganized arrangement of polymer chains. [21,22] Therefore, as the charge carriers inside conducting polymer, the concentrations of polaron (a radical ion associated with a lattice distortion) and bi-polaron are low as well as localized in the pristine PEDOT:PSS.…”