Synergetic Lithium and Hydrogen Bonds Endow Liquid-Free Photonic Ionic Elastomer with Mechanical Robustness and...

Photonic ionic elastomers (PIEs) capable of multiple signal outputs are intriguing in flexible interactive electronics. However, fabricating PIEs with simultaneous mechanical robustness, good ionic conductivity, and brilliant structure color still remains challenging. Here, the limitations are broken through introducing the synergistic effect of lithium and hydrogen bonds into an elastomer. In virtue of lithium bonding between lithium ions and carbonyl groups in the polymer matrix as well as hydrogen bonding between silanol on the surface of silica nanoparticles (SiNPs) and ether groups along polymer chains, the PIEs demonstrate mechanical strength up to 4.3 MPa and toughness up to 8.6 MJ m^-3 . Meanwhile, the synchronous electrical and optical output under mechanical strains can be achieved in the PIEs with the presence of dissociated ions contributed by lithium bond and non-close-packed SiNPs stabilized by the hydrogen bond. Moreover, due to their liquid-free nature, the PIEs exhibit extraordinary stability and durability, which can withstand extreme conditions including both high and low temperatures as well as high humidity. This work provides a promising molecular engineering route to construct high-performance photonic ionic conductors toward advanced ionotronic applications.