Takashi Nakanishi

The development of optoelectronically‐active soft materials is drawing attention to the application of soft electronics. A room‐temperature solvent‐free liquid obtained by modifying a π‐conjugated moiety with flexible yet bulky alkyl chains is a promising functional soft material. Tuning the elastic modulus ( G ′) is essential for employing optoelectronically‐active alkyl–π liquids in deformable devices. However, the range of G ′ achieved through the molecular design of alkyl–π liquids is limited. We report herein a method for controlling G ′ of alkyl–π liquids by gelation. Adding 1 wt % low‐molecular‐weight gelator formed the alkyl–π functional molecular gel (FMG) and increased G ′ of alkyl–π liquids by up to seven orders of magnitude while retaining the optical properties. Because alkyl–π FMGs have functional π‐moieties in the gel medium, this new class of gels has a much higher content of π‐moieties of up to 59 wt % compared to conventional π‐gels of only a few wt %. More importantly, the gel state has a 23 % higher charge‐retention capacity than the liquid, providing better performance in deformable mechanoelectric generator‐electret devices. The strategy used in this study is a novel approach for developing next‐generation optoelectronically‐active FMG materials.