Bioinspired Additive Manufacturing of Hierarchical Materials: From Biostructures to Functions

Throughout billions of years,biological systems have evolved sophisticated,multiscale hierarchical structures to adapt to changing environments.Biomaterials are synthesized under mild conditions through a bottom-up self-assembly process,utilizing substances from the surrounding environment,and meanwhile are regulated by genes and proteins.Additive manufacturing,which mimics this natural process,provides a promising approach to developing new materials with advantageous properties similar to natural biological materials.This review presents an overview of natural biomaterials,emphasizing their chemical and structural compositions at various scales,from the nanoscale to the macroscale,and the key mechanisms underlying their properties.Additionally,this review describes the designs,preparations,and applications of bioinspired multifunctional materials produced through additive manufacturing at different scales,including nano,micro,micro-macro,and macro levels.

Morphology mediation of MoS_(2) nanosheets with organic cations for fast sodium ion storage

Ion diffusion kinetics,depending on the size,tortuosity,connectivity of the channels,greatly affects the rate performance of the electrodes.Two-dimensional materials(2DMs) has emerged as promising electrode materials in the past decades.Howeve r,the applications of 2DMs electrodes are limited by the strong restacking problem,which leads to a poor rate capability.In this work,we for the first time mediated the mo rphology of molybdenum disulfide(MoS_(2)) nanosheets via a facile coagulation method;abundant sheet crumples were induced,which greatly enhance their surface accessibility and thus benefit the ion diffusion kinetics.Consequently,the crumpled-MoS_(2) electrodes follow a capacitive Na-ion charge-storage mechanism to a large extent.Importantly,we demonstrate the special role of organic cations in the inter-sheet assembly configuration,in sharp contrast with that of alkali/alkaline-earth ones.We propose that organic cations cause edge/face contact of the sheets,instead of the face/face contact,thus affording a house-of-cards structure.

Rational design of robust nano-Si/graphite nanocomposites anodes with strong interfacial adhesion for high-performance lithium-ion batteries

The nano-Si/graphite nanocomposites are the promising anodes candidates for high-energy lithium-ion batteries because of their high theoretical capacities and low volume variations.However,the nano-Si has a severe tendency to separate from the graphite substrate due to the inherently weak bonding between them,thus leading to the deteriorated cycling performance and low Coulombic efficiency.Herein,we design a robust nano-Si/graphite nanocomposite structure with strong interfacial adhesion caused by the Si—Ti and Ti—C covalent bonds.The abundant Si—Ti and Ti—C bonds formed between nano-Si and graphite greatly enhance the interfacial adhesion force,resulting in the highly stabilized and integrated electrode structure during battery cycling.Consequently,the as-obtained nano-Si/graphite anodes deliver a high capacity retention of 90.0% after 420 cycles at 0.5 C with an average Coulombic efficiency of 99.5%;moreover,a high initial Coulombic efficiency of 90.2% is achieved.Significantly,this work provides a novel strategy to address the poor interfacial adhesion between nano-Si and graphite,which can be applied to other nano-Si based composites anodes.

Proton-induced fast preparation of size-controllable MoS2 nanocatalyst towards highly efficient water electrolysis

MoS2 has emerged for catalyzing the hydrogen evolution reaction.Various notable strategies have been developed to downsize the MoS2 particles and expose more active edges.However,the restacking issue,which reduces the exposure degree,has rarely been taken into account.Herein,we report on a facile proton-induced fast hydrothermal approach to produce size-controllable MoS2 nanocatalysts and demonstrate that along the varying of sheet sizes,there is a trade-off between the intrinsic catalytic activity(mainly determined by the unsaturated sulfur on the sheet edges)and the active edge accessibility(influenced by the assembly structure).The size-optimized catalyst delivers a high performance of a low overpotential of~200 mV at 10 mA/cm^(2),a Tafel slope of 46.3 mV/dec,and a stable working state,which is comparable to the recent notable works.Our findings will provide a pathway for its large-scale application and enhance the water electrolysis performance.

Bioinspired cellulose-integrated MXene-based hydrogels for multifunctional sensing and electromagnetic interference shielding

Bioinspired hydrogels are complex materials with distinctive properties comparable to biological tissues.Their exceptional sensitivity to various external stimuli leads to substantial application potential in wearable smart devices.However,these multifaceted hydrogels are often challenging to be combined with pattern customization,stimulus responsiveness,self-healing,and biocompatibility.Herein,inspired by mussel secretions,a printable,self-healing,and biocompatible MXene-based composite hydrogel was designed and prepared by incorporating Ti3C2Tx MXene nanosheets into the hydrogel framework through the chelation of calcium ions(Ca2+)with polyacrylic acid and cellulose nanofibers at alkaline conditions.The biocompatible conductive hydrogel exhibited sensitivity(gauge factor of 2.16),self-healing(within 1 s),recognition,and adhesion,distinguishing it as an ideal candidate for wearable multifunctional sensors toward strain sensing,vocal sensing,signature detection,and Morse code transmission.Additionally,the multifunctional hydrogel manifested efficient electromagnetic interference shielding properties(reaching more than 30 dB at a thickness of 2.0 mm),protecting electronics and humans from electromagnetic radiation and pollution.Therefore,the presented work represents a versatile strategy for developing environmentally friendly conductive hydrogels,demonstrating the perspectives of intelligent hydrogels for multifunctional applications.