Research

Jump to: Review

12 pages, 4013 KiB

Open AccessArticle

Organic–Inorganic Hybrid Synaptic Transistors: Methyl-Silsesquioxanes-Based Electric Double Layer for Enhanced Synaptic Functionality and CMOS Compatibility

by Tae-Gyu Hwang, Hamin Park and Won-Ju Cho

Biomimetics 2024, 9(3), 157; https://doi.org/10.3390/biomimetics9030157 - 03 Mar 2024

Viewed by 892

Abstract

Electrical double-layer (EDL) synaptic transistors based on organic materials exhibit low thermal and chemical stability and are thus incompatible with complementary metal oxide semiconductor (CMOS) processes involving high-temperature operations. This paper proposes organic–inorganic hybrid synaptic transistors using methyl silsesquioxane (MSQ) as the electrolyte. [...] Read more.

Electrical double-layer (EDL) synaptic transistors based on organic materials exhibit low thermal and chemical stability and are thus incompatible with complementary metal oxide semiconductor (CMOS) processes involving high-temperature operations. This paper proposes organic–inorganic hybrid synaptic transistors using methyl silsesquioxane (MSQ) as the electrolyte. MSQ, derived from the combination of inorganic silsesquioxanes and the organic methyl (−CH₃) group, exhibits exceptional thermal and chemical stability, thus ensuring compatibility with CMOS processes. We fabricated Al/MSQ electrolyte/Pt capacitors, exhibiting a substantial capacitance of 1.89 µF/cm² at 10 Hz. MSQ-based EDL synaptic transistors demonstrated various synaptic behaviors, such as excitatory post-synaptic current, paired-pulse facilitation, signal pass filtering, and spike-number-dependent plasticity. Additionally, we validated synaptic functions such as information storage and synapse weight adjustment, simulating brain synaptic operations through potentiation and depression. Notably, these synaptic operations demonstrated stability over five continuous operation cycles. Lastly, we trained a multi-layer artificial deep neural network (DNN) using a handwritten Modified National Institute of Standards and Technology image dataset. The DNN achieved an impressive recognition rate of 92.28%. The prepared MSQ-based EDL synaptic transistors, with excellent thermal/chemical stability, synaptic functionality, and compatibility with CMOS processes, harbor tremendous potential as materials for next-generation artificial synapse components. Full article

(This article belongs to the Special Issue Bionic Engineering for Boosting Multidisciplinary Integration)

► Show Figures

Figure 1

10 pages, 3682 KiB

Open AccessArticle

Biomimetic Surface Engineering to Modulate the Coffee-Ring Effect for Amyloid-β Detection in Rat Brains

by Changxin Wang, Lei Li, Jiaze Li, Jun Zhang and Zhi-Bei Qu

Biomimetics 2023, 8(8), 581; https://doi.org/10.3390/biomimetics8080581 - 01 Dec 2023

Viewed by 1165

Abstract

Surface engineering of nanoparticles has been widely used in biosensing and assays, where sensitivity was mainly limited by plasmonic colour change or electrochemical responses. Here, we report a novel biomimetic sensing strategy involving protein-modified gold nanoparticles (AuNPs), where the modulation strategy was inspired [...] Read more.

Surface engineering of nanoparticles has been widely used in biosensing and assays, where sensitivity was mainly limited by plasmonic colour change or electrochemical responses. Here, we report a novel biomimetic sensing strategy involving protein-modified gold nanoparticles (AuNPs), where the modulation strategy was inspired by gastropods in inhibition of coffee-ring effects in their trail-followings. The so-called coffee-ring effect presents the molecular behaviour of AuNPs to a macroscopic ring through aggregation, and thus greatly improves sensitivity. The assay relies upon the different assembly patterns of AuNPs against analytes, resulting in the formation or suppression of coffee-ring effects by the different surface engineering of AuNPs by proteins and peptides. The mechanism of the coffee-ring formation process is examined through experimental characterizations and computational simulations. A practical coffee-ring effect assay is developed for a proof-of-concept target, amyloid β (1–42), which is a typical biomarker of Alzheimer’s disease. A novel quasi-titrimetric protocol is constructed for quantitative determination of the target molecule. The assay shows excellent selectivity and sensitivity for the amyloid β monomer, with a low detection limit of 20 pM. Combined with a fluorescent staining technique, the assay is designed as a smart sensor for amyloid β detection and fibrillation evaluation in rat cerebrospinal fluids, which is a potential point-of-care test for Alzheimer’s disease. Connections between amyloid fibrillation and different courses of brain ischaemia are also studied, with improved sensitivity, lower sample volumes that are required, convenience for rapid detection, and point-of-care testing. Full article

(This article belongs to the Special Issue Bionic Engineering for Boosting Multidisciplinary Integration)

► Show Figures

Graphical abstract

10 pages, 4068 KiB

Open AccessArticle

Continuous 3D Printing of Biomimetic Beetle Mandible Structure with Long Bundles of Aramid Fiber Composites

by Shuigen Li, Chang Liu, Yulong Zhang, Wei Zhang, Xuefei Xu, Zhaohua Lin and Yunhong Liang

Biomimetics 2023, 8(3), 283; https://doi.org/10.3390/biomimetics8030283 - 01 Jul 2023

Viewed by 1229

Abstract

Fiber-reinforced composites are an ideal high-performance composite material made from a combination of high-strength continuous fibers and a polymer matrix. Compared to short cut fibers, continuous long strand fibers can improve the mechanical properties of fiber composites more effectively. Herein, continuous aramid fiber-reinforced [...] Read more.

Fiber-reinforced composites are an ideal high-performance composite material made from a combination of high-strength continuous fibers and a polymer matrix. Compared to short cut fibers, continuous long strand fibers can improve the mechanical properties of fiber composites more effectively. Herein, continuous aramid fiber-reinforced PLA filaments with fiber centering were prepared by modifying the outlet design of a desktop-grade thermoplastic single-screw melt extruder. Inspired by the cross-laminated structure of a beetle’s mandible fibers, a biomimetic structure composite was printed, which demonstrates a significant influence on the mechanical properties. The G-code printing program was developed, and the microstructure of the fracture surface of the specimen was analyzed. The uniform and orderly arrangement of aramid fibers within the PLA resin-based 3D-printed specimen was found. Consequentially, the bionic composites exhibits a 12% increase in tensile strength and a 5% increase in impact toughness, confirming the feasibility of utilizing continuous 3D printing to manufacture long bundles of aramid fiber composite filaments for enhanced mechanical performances. Full article

(This article belongs to the Special Issue Bionic Engineering for Boosting Multidisciplinary Integration)

► Show Figures

Figure 1

16 pages, 6115 KiB

Open AccessArticle

Ultimate Strength Study of Structural Bionic CFRP-Sinker Bolt Assemblies Subjected to Preload under Three-Point Bending

by Zhengqi Qin, Ying He, Shengwu Wang and Cunying Meng

Biomimetics 2023, 8(2), 215; https://doi.org/10.3390/biomimetics8020215 - 23 May 2023

Viewed by 1021

Abstract

Countersunk head bolted joints are one of the main approaches to joining carbon fiber-reinforced plastics, or CFRP. In this paper, the failure mode and damage evolution of CFRP countersunk bolt components under bending load are studied by imitating water bears, which are born [...] Read more.

Countersunk head bolted joints are one of the main approaches to joining carbon fiber-reinforced plastics, or CFRP. In this paper, the failure mode and damage evolution of CFRP countersunk bolt components under bending load are studied by imitating water bears, which are born as adult animals and have strong adaptability to life. Based on the Hashin failure criterion, we establish a 3D finite element failure prediction model of a CFRP-countersunk bolted assembly, benchmarked with the experiment. The analysis shows that the simulation results under specified parameters have a good correlation with the experimental results, and can better reflect the three-point bending failure and fracture of the CFRP-countersunk bolted assembly. Based on the specified parameter of the carbon lamina material change, we used the countersunk bolt preload to investigate the stress distribution near the counterbore zone, and to investigate the effect of bolt load on the three-point bending limit load. The results obtained using FEA calculations indicate that the stress distribution around the countersunk hole is related to the laminate direction. The bolt preloading force increasing reduces the load value at the initial damage, and the appropriate preload force will increase the ultimate load of the joint. Full article

(This article belongs to the Special Issue Bionic Engineering for Boosting Multidisciplinary Integration)

► Show Figures

Figure 1

13 pages, 6751 KiB

Open AccessArticle

Four-Dimensional Printing of Temperature-Responsive Liquid Crystal Elastomers with Programmable Shape-Changing Behavior

by Shuyi Li, Zhengyi Song, Yuyan Fan, Dongsong Wei and Yan Liu

Biomimetics 2023, 8(2), 196; https://doi.org/10.3390/biomimetics8020196 - 09 May 2023

Cited by 2 | Viewed by 1839

Abstract

Liquid crystal elastomers (LCEs) are polymer networks that exhibit anisotropic liquid crystalline properties while maintaining the properties of elastomers, presenting reversible high-speed and large-scale actuation in response to external stimuli. Herein, we formulated a non-toxic, low-temperature liquid crystal (LC) ink for temperature-controlled direct [...] Read more.

Liquid crystal elastomers (LCEs) are polymer networks that exhibit anisotropic liquid crystalline properties while maintaining the properties of elastomers, presenting reversible high-speed and large-scale actuation in response to external stimuli. Herein, we formulated a non-toxic, low-temperature liquid crystal (LC) ink for temperature-controlled direct ink writing 3D printing. The rheological properties of the LC ink were verified under different temperatures given the phase transition temperature of 63 °C measured by the DSC test. Afterwards, the effects of printing speed, printing temperature, and actuation temperature on the actuation strain of printed LCEs structures were investigated within adjustable ranges. In addition, it was demonstrated that the printing direction can modulate the LCEs to exhibit different actuation behaviors. Finally, by sequentially conforming structures and programming the printing parameters, it showed the deformation behavior of a variety of complex structures. By integrating with 4D printing and digital device architectures, this unique reversible deformation property will help LCEs presented here apply to mechanical actuators, smart surfaces, micro-robots, etc. Full article

(This article belongs to the Special Issue Bionic Engineering for Boosting Multidisciplinary Integration)

► Show Figures

Figure 1

16 pages, 3349 KiB

Open AccessEditor’s ChoiceArticle

Biomimetic Design and Topology Optimization of Discontinuous Carbon Fiber-Reinforced Composite Lattice Structures

by Zhong Hu

Biomimetics 2023, 8(2), 148; https://doi.org/10.3390/biomimetics8020148 - 06 Apr 2023

Cited by 2 | Viewed by 1924

Abstract

The ever-increasing requirements for structural performance drive the research and development of lighter, stronger, tougher, and multifunctional composite materials, especially, the lattice structures, heterogeneities, or hybrid compositions have attracted great interest from the materials research community. If it is pushed to the extreme, [...] Read more.

The ever-increasing requirements for structural performance drive the research and development of lighter, stronger, tougher, and multifunctional composite materials, especially, the lattice structures, heterogeneities, or hybrid compositions have attracted great interest from the materials research community. If it is pushed to the extreme, these concepts can consist of highly controlled lattice structures subject to biomimetic material design and topology optimization (TO). However, the strong coupling among the composition and the topology of the porous microstructure hinders the conventional trial-and-error approaches. In this work, discontinuous carbon fiber-reinforced polymer matrix composite materials were adopted for structural design. A three-dimensional (3D) periodic lattice block inspired by cuttlefish bone combined with computer modeling-based topology optimization was proposed. Through computer modeling, complex 3D periodic lattice blocks with various porosities were topologically optimized and realized, and the mechanical properties of the topology-optimized lattice structures were characterized by computer modeling. The results of this work were compared with other similar designs and experiments to validate the effectiveness of the proposed method. The proposed approach provides a design tool for more affordable and higher-performance structural materials. Full article

(This article belongs to the Special Issue Bionic Engineering for Boosting Multidisciplinary Integration)

► Show Figures

Graphical abstract

15 pages, 4988 KiB

Open AccessArticle

Charge Redistribution of Co₉S₈/MoS₂ Heterojunction Microsphere Enhances Electrocatalytic Hydrogen Evolution

by Lili Zhang, Jitang Zhang, Aijiao Xu, Zhiping Lin, Zongpeng Wang, Wenwu Zhong, Shijie Shen and Guangfeng Wu

Biomimetics 2023, 8(1), 104; https://doi.org/10.3390/biomimetics8010104 - 05 Mar 2023

Cited by 6 | Viewed by 1695

Abstract

The electrocatalytic hydrogen evolution activity of transition metal sulfide heterojunctions are significantly increased when compared with that of a single component, but the mechanism behind the performance enhancement and the preparation of catalysts with specific morphologies still need to be explored. Here, we [...] Read more.

The electrocatalytic hydrogen evolution activity of transition metal sulfide heterojunctions are significantly increased when compared with that of a single component, but the mechanism behind the performance enhancement and the preparation of catalysts with specific morphologies still need to be explored. Here, we prepared a Co₉S₈/MoS₂ heterojunction with microsphere morphology consisting of thin nanosheets using a facile two-step method. There is electron transfer between the Co₉S₈ and MoS₂ of the heterojunction, thus realizing the redistribution of charge. After the formation of the heterojunction, the density of states near the Fermi surface increases, the d-band center of the transition metal moves downward, and the adsorption of both water molecules and hydrogen by the catalyst are optimized. As a result, the overpotential of Co₉S₈/MoS₂ is superior to that of most relevant electrocatalysts reported in the literature. This work provides insight into the synergistic mechanisms of heterojunctions and their morphological regulation. Full article

(This article belongs to the Special Issue Bionic Engineering for Boosting Multidisciplinary Integration)

► Show Figures

Figure 1

Review

Jump to: Research

17 pages, 65288 KiB

Open AccessReview

Lightweight Structural Biomaterials with Excellent Mechanical Performance: A Review

by Zhiyan Zhang, Zhengzhi Mu, Yufei Wang, Wenda Song, Hexuan Yu, Shuang Zhang, Yujiao Li, Shichao Niu, Zhiwu Han and Luquan Ren

Biomimetics 2023, 8(2), 153; https://doi.org/10.3390/biomimetics8020153 - 12 Apr 2023

Cited by 3 | Viewed by 2666

Abstract

The rational design of desirable lightweight structural materials usually needs to meet the strict requirements of mechanical properties. Seeking optimal integration strategies for lightweight structures and high mechanical performance is always of great research significance in the rapidly developing composites field, which also [...] Read more.

The rational design of desirable lightweight structural materials usually needs to meet the strict requirements of mechanical properties. Seeking optimal integration strategies for lightweight structures and high mechanical performance is always of great research significance in the rapidly developing composites field, which also draws significant attention from materials scientists and engineers. However, the intrinsic incompatibility of low mass and high strength is still an open challenge for achieving satisfied engineering composites. Fortunately, creatures in nature tend to possess excellent lightweight properties and mechanical performance to improve their survival ability. Thus, by ingenious structure configuration, lightweight structural biomaterials with simple components can achieve high mechanical performance. This review comprehensively summarizes recent advances in three typical structures in natural biomaterials: cellular structures, fibrous structures, and sandwich structures. For each structure, typical organisms are selected for comparison, and their compositions, structures, and properties are discussed in detail, respectively. In addition, bioinspired design approaches of each structure are briefly introduced. At last, the outlook on the design and fabrication of bioinspired composites is also presented to guide the development of advanced composites in future practical engineering applications. Full article

(This article belongs to the Special Issue Bionic Engineering for Boosting Multidisciplinary Integration)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Bionic Engineering for Boosting Multidisciplinary Integration

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (8 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI