Biomimetic enzyme cascade reaction systems in microcapsules are developed for mimicking biocatalysis of organelles.

Skin interstitial fluid (ISF) is considered as an emerging source of biomarkers with physiological and medical significance. Microneedle arrays (MNs) provide a promising means for painless, noninvasive detection of these biomarkers. Here, novel MNs integrated with photonic crystal (PhC) barcodes are presented, and multiplex specific detection of ISF biomarkers is realized for the first time. The PhC barcodes‐loaded flexible MNs are simply fabricated by replicating dynamic ferrofluid‐cast micromoldings. When the prepared MNs are inserted into skin, they can enrich specific biomarkers to their probes‐decorated PhC barcodes. Thus, by adding corresponding fluorescent probes to form sandwich immunocomplexes, the relative content of the biomarkers can be read out through the fluorescence intensity of the barcodes; meanwhile, the species of these biomarkers can be clearly distinguished by the reflection peaks of the PhC barcodes. Based on the encoded MNs, their sensitivity, flexibility, and versatility of capturing and detecting three inflammatory cytokines are demonstrated in a sepsis mice model. Compared with existing MNs for ISF detection, the encoded MNs not only possess equivalent detection effects with less post‐processing and simplified procedures, but can also detect multiple biomarkers simultaneously, which makes them ideal in many clinical and biomedical detection areas.

The manipulation of liquid droplets demonstrates great importance in various areas from laboratory research to our daily life. Here, inspired by the unique microstructure of plant stomata, we present a surface with programmable wettability arrays for droplets manipulation. The substrate film of this surface is constructed by using a coaxial capillary microfluidics to emulsify and pack graphene oxide (GO) hybridN-isopropylacrylamide (NIPAM) hydrogel solution into silica nanoparticles-dispersed ethoxylated trimethylolpropane triacrylate (ETPTA) phase. Because of the distribution of the silica nanoparticles on the ETPTA interface, the outer surface of the film could achieve favorable hydrophobic property under selective fluorosilane decoration. Owing to the outstanding photothermal energy transformation property of the GO, the encapsulated hydrophilic hydrogel arrays could shrink back into the holes to expose their hydrophobic surface with near-infrared (NIR) irradiation; this imparts the composite film with remotely switchable surface droplet adhesion status. Based on this phenomenon, we have demonstrated controllable droplet sliding on programmable wettability pathways, together with effective droplet transfer for printing with mask integration, which remains difficult to realize by existing techniques.

This review comprehensively discusses recent advances in the basic components, controlling methods and especially in the applications of biohybrid robots.