Flexible and Transparent Ionic Liquids/Poly(vinylidene fluoride) Composition‐Gradient Piezo‐Active Composites for Highly Sensitive Pressure Sensor

Abstract

Nowadays, the advent of pressure sensors for intelligence terminal devices and skin‐inspired electronics has trigged rapid development of flexible, sensitive, and transparent sensing materials. Piezo‐active poly(vinylidene fluoride) (PVDF) is emerging as a promising candidate for sensing components due to the flexible and transparent features. However, the inherent weak piezo‐activity and consequently low sensitivity of PVDF remains a challenge for its sensing applications. Herein, ionic liquids ([EMIM]Cl) additive combined with a composition‐gradient multilayered architecture design are employed to hardness the piezo‐response of PVDF. The resultant composites present ultra‐high piezoelectric coefficient d33 of 39 pC N−1, which is 2.78 times that of PVDF. Meanwhile, the transparent ILs dopant enables the composites with superior transparency (87%). With notable advantages of high transparency and piezoelectricity, the ILs/PVDF composites exhibit high sensitivity of 0.0423 V N−1, ultra‐fast recovery time of 0.2 ms and stable operation capability when coupled with metal electrodes, confirming their applicability for reliable pressure sensor.

Pronounced Chirality Effect on the Ferroelectricity of Hydrogen-Bonded Supramolecular Assemblies of Ambipolar Chromophoric Systems

“…The estimated value of d 33 in the 30:70 achiral/chiral film is around 49 pm V –1 as compared to ∼60 pm V –1 measured from the 100% chiral molecule. These values are quite at par with other organic ferroelectric systems and in polymers and may prove to be potential piezoelectric sensing and energy harvesting candidates …”

“…These values are quite at par with other organic ferroelectric systems and in polymers and may prove to be potential piezoelectric sensing and energy harvesting candidates. 41 ■…”