Hierarchical Structured Fabrics with Enhanced Pressure Sensing Performance Based on Orientated Growth of Functional Bacterial Cellulose

Wearable electronics based on natural biomaterials,such as bacterial cellulose(BC),have shown promise for a variety of healthcare and human-computer interaction applications.However,current BC-based pressure sensors have an inherent limi-tation,which is the two-dimensional rigid structures and limited compressibility of BC restrict the sensitivity and working range for pressure sensing.Here,we propose a strategy for fabricating BC/polypyrrole/spacer fabric(BPSF)pressure sensors with a hierarchical structure constructed by integrating conductive BC nanonetwork into a compressible fabric frame via the in situ biofermentation process.The hierarchical structure design includes a cross-scale network from the nanoscale BC sensor networks to the macroscopic three-dimensional compressible fabric sensor network,which significantly improves the working range(0-300 kPa)and sensitivity(40.62 kPa-1)of BPSF.Via this unique structural design,the sensor also achieves a high fatigue life(~5000 cycles),wearability,and reproducibility even after several washing and abrasion cycles.Furthermore,a flexible and wearable electronic textile featuring an n×n sensing matrix was developed by constructing BPSF arrays,allowing for the precise control of machines and weight distribution analysis.These empirical insights are valuable for the biofabrication and textile structure design of wearable devices toward the realization of highly intuitive human-machine interfaces.

A Novel Hierarchical Porous 3D Structured Vanadium Nitride/Carbon Membranes for High-performance Supercapacitor Negative Electrodes

Transition-metal nitrides exhibit wide potential windows and good electrochemical performance, but usually experience imbalanced practical applications in the energy storage field due to aggregation, poor circulation stability, and complicated syntheses. In this study, a novel and simple multiphase polymeric strategy was developed to fabricate hybrid vanadium nitride/carbon(VN/C) membranes for supercapacitor negative electrodes, in which VN nanoparticles were uniformly distributed in the hierarchical porous carbon 3D networks. The supercapacitor negative electrode based on VN/C membranes exhibited a high specific capacitance of 392.0 F g^(-1) at 0.5 A g^(-1) and an excellent rate capability with capacitance retention of 50.5% at 30 A g^(-1). For the asymmetric device fabricated using Ni(OH)_2//VN/C membranes, a high energy density of 43.0 Wh kg^(-1) at a power density of800 W kg^(-1) was observed. Moreover, the device also showed good cycling stability of 82.9% at a current density of 1.0 A g^(-1) after 8000 cycles. This work may throw a light on simply the fabrication of other high-performance transition-metal nitridebased supercapacitor or other energy storage devices.

Fabrication and catalytic behavior of hierarchically-structured nylon 6 nanofiber membrane decorated with silver nanoparticles

A hierarchically‐structured nylon 6 (PA6) nanofiber membrane decorated with silver nanoparticles (Ag NPs) was fabricated by electrospinning and impregnation methods. The as‐fabricated hierarchically‐structured Ag/PA6 nanofiber membrane (HS‐Ag/PA6 NM) exhibits a morphology in which Ag NPs are deposited on the surfaces of both thick fibers and thin fibers. The content and size of theAg NPs can be controlled by varying the concentration of the silver colloid solution. Compared with the non‐hierarchically‐structured Ag/PA6 nanofiber membrane, HS‐Ag/PA6 NM has a higher specificsurface area and exhibits a higher degradation rate for methylene blue of 81.8%–98.1% within2 h. HS‐Ag/PA6 NM can be easily recycled and exhibits good reusability. It retains a degradation rate for methylene blue of 83.5% after five consecutive cycles. The hierarchically‐structured nanofiber membrane is therefore a potential nanocatalyst.

A hierarchically structured tin-cobalt composite with an enhanced electronic effect for high-performance CO_(2) electroreduction in a wide potential range

Earth-abundant and nontoxic Sn-based materials have been regarded as promising catalysts for the electrochemical conversion of CO_(2)to C1 products,e.g.,CO and formate.However,it is still difficult for Snbased materials to obtain satisfactory performance at low-to-moderate overpotentials.Herein,a simple and facile electrospinning technique is utilized to prepare a composite of a bimetallic Sn-Co oxide/carbon matrix with a hollow nanotube structure(Sn Co-HNT).Sn Co-HNT can maintain>90%faradaic efficiencies for C1 products within a wide potential range from-0.6 VRHE to-1.2 VRHE,and a highest 94.1%selectivity towards CO in an H-type cell.Moreover,a 91.2%faradaic efficiency with a 241.3 m A cm^(-2)partial current density for C1 products could be achieved using a flow cell.According to theoretical calculations,the fusing of Sn/Co oxides on the carbon matrix accelerates electron transfer at the atomic level,causing electron deficiency of Sn centers and reversible variation between Co^(2+)and Co^(3+)centers.The synergistic effect of the Sn/Co composition improves the electron affinity of the catalyst surface,which is conducive to the adsorption and stabilization of key intermediates and eventually increases the catalytic activity in CO_(2)electroreduction.This study could provide a new strategy for the construction of oxide-derived catalysts for CO_(2)electroreduction.

Hierarchical platinum–iridium neural electrodes structured by femtosecond laser for superwicking interface and superior charge storage capacity

The interfacial performance of implanted neural electrodes is crucial for stimulation safety and the recording quality of neuronal activity.This paper proposes a novel surface architecture and optimization strategy for the platinum–iridium(Pt–Ir)electrode to optimize electrochemical performance and wettability.A series of surface micro/nano structures were fabricated on Pt–Ir electrodes with different combinations of four adjustable laser-processing parameters.Subsequently,the electrodes were characterized by scanning electron microscopy,energy-dispersive X-ray spectroscopy,cyclic voltammetry,electrochemical impedance spectroscopy,and wetting behavior.The results show that electrode performance strongly depends on the surface morphology.Increasing scanning overlap along with moderate pulse energy and the right number of pulses leads to enriched surface micro/nano structures and improved electrode performance.It raises the maximum charge storage capacity to 128.2 mC/cm^(2) and the interface capacitance of electrodes to 3.0×10^(4)μF/cm^(2) for the geometric area,compared with 4.6 mC/cm^(2) and 443.1μF/cm2,respectively,for the smooth Pt–Ir electrode.The corresponding optimal results for the optically measured area are 111.8 mC/cm^(2) and 2.6×10^(4)μF/cm^(2),which indicate the contribution of fner structures to the ablation profle.The hierarchical structures formed by the femtosecond laser dramatically enhanced the wettability of the electrode interface,giving it superwicking properties.A wicking speed of approximately 80 mm/s was reached.Our optimization strategy,leading to superior performance of the superwicking Pt–Ir interface,is promising for use in new neural electrodes.

Advancing the pressure sensing performance of conductive CNT/PDMS composite film by constructing a hierarchical-structured surface

Flexible pressure sensors have attracted wide attention due to their applications to electronic skin,health monitoring,and human-machine interaction.However,the tradeoff between their high sensitivity and wide response range remains a challenge.Inspired by human skin,we select commercial silicon carbide sandpaper as a template to fabricate carbon nanotube(CNT)/polydimethylsiloxane(PDMS)composite film with a hierarchical structured surface(h-CNT/PDMS)through solution blending and blade coating and then assemble the h-CNT/PDMS composite film with interdigitated electrodes and polyurethane(PU)scotch tape to obtain an h-CNT/PDMS-based flexible pressure sensor.Based on in-situ optical images and finite element analysis,the significant compressive contact effect between the hierarchical structured surface of h-CNT/PDMS and the interdigitated electrode leads to enhanced pressure sensitivity and a wider response range(0.1661 kPa^(-1),0.4574 kPa^(-1)and 0.0989 kPa^(-1)in the pressure range of 0–18 kPa,18–133 kPa and 133–300 kPa)compared with planar CNT/PDMS composite film(0.0066 kPa^(-1)in the pressure range of 0–240 kPa).The prepared pressure sensor displays rapid response/recovery time,excellent stability,durability,and stable response to different loading modes(bending and torsion).In addition,our pressure sensor can be utilized to accurately monitor and discriminate various stimuli ranging from human motions to pressure magnitude and spatial distribution.This study supplies important guidance for the fabrication of flexible pressure sensors with superior sensing performance in next-generation wearable electronic devices.

Structural Engineering of Hierarchical Magnetic/Carbon Nanocomposites via In Situ Growth for High-Efficient Electromagnetic Wave Absorption

Materials exhibiting high-performance electromagnetic wave absorption have garnered considerable scientific and technological attention,yet encounter significant challenges.Developing new materials and innovative structural design concepts is crucial for expanding the application field of electromagnetic wave absorption.Particularly,hierarchical structure engineering has emerged as a promising approach to enhance the physical and chemical properties of materials,providing immense potential for creating versatile electromagnetic wave absorption materials.Herein,an exceptional multi-dimensional hierarchical structure was meticulously devised,unleashing the full microwave attenuation capabilities through in situ growth,selfreduction,and multi-heterogeneous interface integration.The hierarchical structure features a three-dimensional carbon framework,where magnetic nanoparticles grow in situ on the carbon skeleton,creating a necklace-like structure.Furthermore,magnetic nanosheets assemble within this framework.Enhanced impedance matching was achieved by precisely adjusting component proportions,and intelligent integration of diverse interfaces bolstered dielectric polarization.The obtain Fe_(3)O_(4)-Fe nanoparticles/carbon nanofibers/Al-Fe_(3)O_(4)-Fe nanosheets composites demonstrated outstanding performance with a minimum reflection loss(RLmin)value of−59.3 dB and an effective absorption bandwidth(RL≤−10 dB)extending up to 5.6 GHz at 2.2 mm.These notable accomplishments offer fresh insights into the precision design of high-efficient electromagnetic wave absorption materials.

Hierarchical structures on platinum-iridium substrates enhancing conducting polymer adhesion

Conducting polymers(CPs),including poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS),are promising coating materials for neural electrodes.However,the weak adhesion of CP coatings to substrates such as platinum-iridium is a significant challenge that limits their practical application.To address this issue,we used femtosecond laser-prepared hierarchical structures on platinum-iridium(Pt-Ir)substrates to enhance the adhesion of PEDOT:PSS coatings.Next,we used cyclic voltammetry(CV)stress and accelerated aging tests to evaluate the stability of both drop cast and electrodeposited PEDOT:PSS coatings on Pt-Ir substrates,both with and without hierarchical structures.Our results showed that after 2000 CV cycles or five weeks of aging at 60℃,the morphology and electrochemical properties of the coatings on the Pt-Ir substrates with hierarchical structures remained relatively stable.In contrast,we found that smooth Pt-Ir substrate surfaces caused delamination of the PEDOT:PSS coating and exhibited both decreased charge storage capacity and increased impedance.Overall,enhancing the stability of PEDOT:PSS coatings used on common platinum-iridium neural electrodes offers great potential for improving their electrochemical performance and developing new functionalities.

Achieving the synergistic of strength and ductility in Mg-15Gd-1Zn-0.4Zr alloy with hierarchical structure

Currently,the hierarchical structure is one of the most effective means to enhance the strength and plasticity of metal materials,since the strain localization can be effectively delayed by the coordination of the unique microstructure.In this study,a hierarchical structure of Mg-15Gd-1Zn-0.4Zr(GZ151K)alloys containing grain,twin,and precipitation structural units was prepared by ultrasonic surface rolling process(USRP)and recrystallization annealing(RU).The results showed that the stress gradient generated by USRP formed a twin gradient structure,which will activate the twin-assisted precipitation(TAP)effect and twin-induced recrystallization(TIR)effect during RU.Then,the twin gradient structure transformed into a twin-precipitation gradient structure,and finally into a hierarchical structure with grain-twinprecipitation as the increasement of recrystallization degree.Besides,the dual gradient structure with twin and precipitation structural units had the highest strength and microhardness owing to the precipitation strengthening.However,the hierarchical structure with grain,twin,and precipitation structural units exhibited the most excellent combination of strength and plasticity under grain refinement and precipitation strengthening.

A hierarchical salt-rejection strategy for sustainable and high-efficiency solar-driven desalination

Solar steam generation(SSG)is widely regarded as one of the most sustainable technologies for seawater desalination.However,salt fouling severely compromises the evaporation performance and lifetime of evaporators,limiting their practical applications.Herein,we propose a hierarchical salt-rejection(HSR)strategy to prevent salt precipitation during long-term evaporation while maintaining a rapid evaporation rate,even in high-salinity brine.The salt diffusion process is segmented into three steps—insulation,branching diffusion,and arterial transport—that significantly enhance the salt-resistance properties of the evaporator.Moreover,the HSR strategy overcomes the tradeoff between salt resistance and evaporation rate.Consequently,a high evaporation rate of 2.84 kg m^(-2) h^(-1),stable evaporation for 7 days cyclic tests in 20 wt%NaCl solution,and continuous operation for 170 h in natural seawater under 1 sun illumination were achieved.Compared with control evaporators,the HSR evaporator exhibited a>54%enhancement in total water evaporation mass during 24 h continuous evaporation in 20 wt%salt water.Furthermore,a water collection device equipped with the HSR evaporator realized a high water purification rate(1.1 kg m^(-2) h^(-1)),highlighting its potential for agricultural applications.

Remarkably Enhanced Methane Sensing Performance at Room Temperature via Constructing a Self-Assembled Mulberry-Like ZnO/SnO_(2) Hierarchical Structure

Development of metal oxide semiconductors-based methane sensors with good response and low power consumption is one of the major challenges to realize the real-time monitoring of methane leakage.In this work,a self-assembled mulberry-like ZnO/SnO_(2)hierarchical structure is constructed by a two-step hydrothermal method.The resultant sensor works at room temperature with excellent response of~56.1%to 2000 ppm CH_(4)at 55%relative humidity.It is found that the strain induced at the ZnO/SnO_(2)interface greatly enhances the piezoelectric polarization on the ZnO surface and that the band bending results in the accumulation of chemically adsorbed O_(2)^(-)ions close to the interface,leading to significant improvement in the sensing performance of the methane gas sensor at room temperature.

Nano-Au-decorated hierarchical porous cobalt sulfide derived from ZIF-67 toward optimized oxygen evolution catalysis:Important roles of microstructures and electronic modulation

Enhancing both the number of active sites available and the intrinsic activity of Co-based electrocatalysts simultaneously is a desirable goal.Herein,a ZIF-67-derived hierarchical porous cobalt sulfide decorated by Au nanoparticles(NPs)(denoted as HP-Au@CoxSy@ZIF-67)hybrid is synthesized by low-temperature sulfuration treatment.The well-defined macroporous-mesoporous-microporous structure is obtained based on the combination of polystyrene spheres,as-formed CoxSy nanosheets,and ZIF-67 frameworks.This novel three-dimensional hierarchical structure significantly enlarges the three-phase interfaces,accelerating the mass transfer and exposing the active centers for oxygen evolution reaction.The electronic structure of Co is modulated by Au through charge transfer,and a series of experiments,together with theoretical analysis,is performed to ascertain the electronic modulation of Co by Au.Meanwhile,HP-Au@CoxSy@ZIF-67 catalysts with different amounts of Au were synthesized,wherein Au and NaBH4 reductant result in an interesting“competition effect”to regulate the relative ratio of Co^(2+)/Co^(3+),and moderate Au assists the electrochemical performance to reach the highest value.Consequently,the optimized HP-Au@CoxSy@ZIF-67 exhibits a low overpotential of 340 mV at 10 mA cm^(-2)and a Tafel slope of 42 mV dec-1 for OER in 0.1 M aqueous KOH,enabling efficient water splitting and Zn-air battery performance.The work here highlights the pivotal roles of both microstructural and electronic modulation in enhancing electrocatalytic activity and presents a feasible strategy for designing and optimizing advanced electrocatalysts.

Self-assembly of hierarchical ZnSnO_3-SnO_2 nanoflakes and their gas sensing properties

A new type of hierarchical ZnSnO3-SnO2 flower-shaped nanostructure composed of thin nanoflakes as secondary units is successfully prepared through a simple hydrothermal process. The polyhedral ZnSnO3 core acts as a sacrificed template for the growth of hierarchical SnO2 nanoflakes, and the average thickness of SnO2 nanoflakes is around 25 nm. The time-dependent morphology evolution of ZnSnO3-SnO2 samples was investigated, and a possible formation mechanism of these hierarchical structures is discussed. The gas sensor based on these novel ZnSnO3-SnO2 nanostructures exhibits high response and quick response- recovery traits to ethanol （C2H5OH）. It is found that ZnSnO3-SnO2 nanoflakes have a response of 27.8 to 50×10-6 C2H5OH at the optimal operating temperature of 270 °C, and the response and recovery time are within 1.0 and 1.8 s, respectively.

Effects of hierarchical structure on the performance of tin oxide-supported platinum catalyst for room-temperature formaldehyde oxidation

Flower-like tin oxide-supported platinum（Pt/SnOx） with a hierarchical structure was synthesized by a hydrothermal method and characterized by XRD,SEM,TEM,high resolution TEM,XPS and nitrogen adsorption.The flower-like Pt/SnOx microspheres of 1 μm in diameter were composed of staggered petal-like nanosheets with a thickness of 20 nm.Pt nanoparticles（NPs） of 2-3 nm were well dispersed on the SnOx nanosheets.The catalyst was tested in the catalytic oxidation of gaseous formaldehyde（HCHO） at room temperature,and exhibited enhanced activity compared to Pt NPs supported on commercial SnO and ground SnOx.HCHO removal of 87%was achieved over the hierarchical Pt/SnOx after 1 h of reaction,which was 1.5 times that over the ground SnOx-supported Pt（Pt/g-SnOx）,and the high activity was maintained after six recycles,showing the high stability of this catalyst.HCHO decomposition kinetics was modeled as a second order reaction.The reaction rate constant for Pt/SnOx was 5.6 times higher than Pt/g-SnOx.The hierarchical pore structure was beneficial for the diffusion and adsorption of HCHO molecules,and the highly dispersed Pt NPs on the SnOx nanosheets were the active sites for the oxidative decomposition of HCHO into CO2 and H2O.This study provided a promising approach for designing efficient catalysts for indoor HCHO removal at ambient temperature.

Integration of Multiple Heterointerfaces in a Hierarchical 0D@2D@1D Structure for Lightweight,Flexible,and Hydrophobic Multifunctional Electromagnetic Protective Fabrics

The development of wearable multifunctional electromagnetic protective fabrics with multifunctional,low cost,and high efficiency remains a challenge.Here,inspired by the unique flower branch shape of“Thunberg’s meadowsweet”in nature,a nanofibrous composite membrane with hierarchical structure was constructed.Integrating sophisticated 0D@2D@1D hierarchical structures with multiple heterointerfaces can fully unleash the multifunctional application potential of composite membrane.The targeted induction method was used to precisely regulate the formation site and morphology of the metal–organic framework precursor,and intelligently integrate multiple heterostructures to enhance dielectric polarization,which improves the impedance matching and loss mechanisms of the electromagnetic wave absorbing materials.Due to the synergistic enhancement of electrospinning-derived carbon nanofiber“stems”,MOF-derived carbon nanosheet“petals”and transition metal selenide nano-particle“stamens”,the CoxSey/NiSe@CNSs@CNFs(CNCC)composite membrane obtains a minimum reflection loss value(RL_(min))of-68.40 dB at 2.6 mm and a maximum effective absorption bandwidth(EAB)of 8.88 GHz at a thin thickness of 2.0 mm with a filling amount of only 5 wt%.In addition,the multi-component and hierarchical heterostructure endow the fibrous membrane with excellent flexibility,water resistance,thermal management,and other multifunctional properties.This work provides unique perspectives for the precise design and rational application of multifunctional fabrics.

Hierarchical Ni-Al hydrotalcite supported Pt catalyst for efficient catalytic oxidation of formaldehyde at room temperature

Catalytic oxidation at room temperature is recognized as the most promising method for formaldehyde(HCHO)removal.Pt‐based catalysts are the optimal catalyst for HCHO decomposition at room temperature.Herein,flower‐like hierarchical Pt/NiAl‐LDHs catalysts with different[Ni2+]/[Al3+]molar ratios were synthesized via hydrothermal method followed by NaBH4 reduction of Pt precursor at room temperature.The flower‐like hierarchical Pt/NiAl‐LDHs were composed of interlaced nanoplates and metallic Pt nanoparticles(NPs)approximately 3–4 nm in diameter were loaded on the surface of the Pt/NiAl‐LDHs with high dispersion.The as‐prepared Pt/NiAl21 nanocomposite was highly efficient in catalyzing oxidation of HCHO into CO2 at room temperature.The high activity of the hierarchical Pt/NiAl21 nanocomposite was maintained after seven recycle tests,suggesting the high stability of the catalyst.Based on in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)studies,a reaction mechanism was put forward about HCHO decomposition at room temperature.This work provides new insights into designing and fabricating high‐performance catalysts for efficient indoor air purification.

Lotus Leaf‑Derived Gradient Hierarchical Porous C/MoS2 Morphology Genetic Composites with Wideband and Tunable Electromagnetic Absorption Performance

Inspired by the nature,lotus leaf-derived gradient hierarchical porous C/MoS2 morphology genetic composites(GHPCM)were successfully fabricated through an in situ strategy.The biological microstructure of lotus leaf was well preserved after treatment.Different pores with gradient pore sizes ranging from 300 to 5μm were hierarchically distributed in the composites.In addition,the surface states of lotus leaf resulted in the Janus-like morphologies of MoS2.The GHPCM exhibit excellent electromagnetic wave absorption performance,with the minimum reflection loss of−50.1 dB at a thickness of 2.4 mm and the maximum effective bandwidth of 6.0 GHz at a thickness of 2.2 mm.The outstanding performance could be attributed to the synergy of conductive loss,polarization loss,and impedance matching.In particularly,we provided a brand-new dielectric sum-quotient model to analyze the electromagnetic performance of the non-magnetic material system.It suggests that the specific sum and quotient of permittivity are the key to keep reflection loss below−10 dB within a certain frequency range.Furthermore,based on the concept of material genetic engineering,the dielectric constant could be taken into account to seek for suitable materials with designable electromagnetic absorption performance.

Hierarchically porous nitrogen-doped carbon as cathode for lithium–sulfur batteries

Porous nitrogen-doped carbon is an especially promising material energy storage due to its excellentconductivity, stable physicochemical properties, easy processability, controllable porosity and low price.Herein, we reported a novel well-designed hierarchically porous nitrogen-doped carbon （HPNC） via acombination of salt template （ZnC12） and hard template （SiO2） as sulfur host for lithium-sulfur batter-ies. The low-melting ZnC12 is boiled off and leaves behind micropores and small size mesopores duringpyrolysis process, while the silica spheres are removed by acid leaching to generate interconnected 3Dnetwork of macropores. The HPNC-S electrode exhibits an initial specific capacity of 1355 mAh g^-l at 0.IC （IC= 1675 mAh g^-1 ）, a high-rate capability of 623 mAh g-l at 2 C, and a small decay of 0.13% per cycleover 300 cycles at 0.2 C. This excellent rate capability and remarkable long-term cyclability of the HPNC-Selectrode are attributed to its hierarchical porous structures for confining the soluble lithium polysulfideas well as the nitrogen doping for high absorbability of lithium polysulfide.

High-performance all-solid-state polymer electrolyte with fast conductivity pathway formed by hierarchical structure polyamide 6 nanofiber for lithium metal battery

The utilization of all-solid-state electrolytes is considered to be an effective way to enhance the safety performance of lithium metal batteries.However,the low ionic conductivity and poor interface compatibility greatly restrict the development of all-solid-state battery.In this study,a composite electrolyte combining the electrospun polyamide 6(PA6)nanofiber membrane with hierarchical structure and the polyethylene oxide(PEO)polymer is investigated.The introduction of PA6 nanofiber membrane can effectively reduce the crystallinity of the polymer,so that the ionic conductivity of the electrolyte can be enhanced.Moreover,it is found that the presence of finely branched fibers in the hierarchical structure PA6 membrane allows the polar functional groups(C=O and N-H bonds)to be fully exposed,which provides sufficient functional sites for lithium ion transport and helps to regulate the uniform deposition of lithium metal.Moreover,the hierarchical structure can enhance the mechanical strength(9.2 MPa)of the electrolyte,thereby effectively improving the safety and cycle stability of the battery.The prepared Li/Li symmetric battery can be stably cycled for 1500 h under 0.3 mA cm^(-2) and 60℃.This study demonstrates that the prepared electrolyte has excellent application prospects in the next generation all-solid-state lithium metal batteries.

Hierarchical structure observation and nanoindentation size effect characterization for a limnetic shell

In the present research, hierarchical structure observation and mechanical property characterization for a type of biomaterial are carried out. The investigated bioma- terial is Hyriopsis cumingii, a typical limnetic shell, which consists of two different structural layers, a prismatic ＂pillar＂ structure and a nacreous ＂brick and mortar＂ structure. The prismatic layer looks like a ＂pillar forest＂ with variationsection pillars sized on the order of several tens of microns. The nacreous material looks like a ＂brick wall＂ with bricks sized on the order of several microns. Both pillars and bricks are composed of nanoparticles. The mechanical properties of the hierarchical biomaterial are measured by using the nanoindentation test. Hardness and modulus are measured for both the nacre layer and the prismatic layer, respectively. The nanoindentation size effects for the hierarchical structural materials are investigated experimentally. The results show that the prismatic nanostructured material has a higher stiffness and hardness than the nacre nanostructured material. In addition, the nanoindentation size effects for the hierarchical structural materials are described theoretically, by using the trans-scale mechanics theory considering both strain gradient effect and the surface/interface effect. The modeling results are consistent with experimental ones.