Octopus-like Microstructure of Graphene Oxide Generated through Laser-Microdroplet Interaction for Adhesive Coating.

The octopus, as one of the most famous celebrities in bionics, has provided various inspirations for camouflage materials, soft-bodied robots, and flexible grabbers. The miniaturization of such structures will help the development of microrobots, microdelivery of drugs, and surface coating. With the lack of relevant effective preparation approaches, however, the generation of such octopus-like structures with a size of ∼1 μm or below is challenging. Here, we develop an approach based on laser-microdroplet interaction for generating an octopus-like structure with a size of ∼1 μm. The developed approach uses laser-microdroplet interaction to provide a large driving force of ∼10 7 Pa at a confined space (<1 μm), locally crumpling the precursor in the microdroplet. The locally crumpled particles possess both crumpled and uncrumpled structures that resemble an octopus's head and soft body. In the adhesion test, the octopus-like particles exhibit high adhesive properties in air, in water, and on a flexible substrate. In the electrochemical test, the octopus-like particles on flexible electrodes show good electrochemical and adhesive properties under hundreds of bending cycles. Benefiting from the combination of crumpled and uncrumpled morphologies, the created particles with octopus-like microstructure are demonstrated to possess comprehensive performance, exhibiting wide application potentials in the fields of microswimmers, surface coatings, and electrochemistry. Additionally, the method developed in this work has the advantages of concentrated energy in a confined space, displaying prospective potentials in micro- and nanoprocessing.