Chameleon skin is naturally adaptive and can sense environmental changes and transform sensing into bioelectrical and optical signals by manipulating ion transduction and photonic nanostructures. The increasing interest in mimicking biological skins has considerably promoted the development of advanced photonic materials with an increasing ionic conductivity. Herein, we report the judicious design and fabrication of a bioinspired mechanochromic chiral nematic nanostructured film with good ionic conductivity by infiltrating fluorine-rich ionic liquids (FILs) into a swollen self-assembled cellulose nanocrystal (CNC) film with helical nanoarchitectures. Notably, the introduction of 2-hydroxyethyl acrylate considerably enhances the compatibility of hydrophobic FILs and hydrophilic CNCs. The resulting FIL−CNC nanostructured films exhibited excellent mechanochromism, good ionic conductivity, and outstanding optical/electrical dual-signal sensing performance when used as a bioinspired ionic skin for realtime monitoring of human motions. Owing to the integration of FILs, the underwater stability of the chiral liquid crystal nanostructures of CNCs was significantly enhanced. Notably, underwater contact/contactless sensing modes and encrypted information transmission have been achieved with the FIL−CNC nanostructured film. This study can offer great insights for the advancement of biomimetic multifunctional artificial skins and emerging interactive devices, which can find important applications in wearable iontronics, human−machine interactions, and intelligent robots.

Bubbling carbonation is the most widely used method for production of CaCO3. A structure-controllable preparation of calcium carbonate with homogeneous crystallinity and narrow particle size distribution is generally required. In this work, a gas distributor is designed and fabricated by light-curing three-dimensional (3D) printing technology to optimize the pore size and distribution of the distributor. The printed gas distributor is combined with a home-made glass vessel to form a simple carbonation reactor without the need for stirring. With the optimized gas flow rate and concentration of Ca(OH)2, this reactor produces small-sized bubbles continuously and uniformly. A homogeneous bubble flow regime can be thus easily formed with the printed distributor, which leads to an enhanced production of calcium carbonate at room temperature with a uniform morphology and narrow particle size distribution. The time required for carbonization is significantly reduced as well. The present study extends the 3D printing to the construction of bubbling reactors with broad applications beyond production of CaCO3.