Natural Organisms Research Articles

Bioinspired Dynamic Matrix Based on Developable Structure of MXene‐Cellulose Nanofibers (CNF) Soft Actuators

AbstractInspired by natural organisms, soft actuators can convert environmental stimuli into mechanical deformation, making them indispensable for applications in a variety of fields such as soft robotics. MXene, displaying exceptional attributes in conductivity, thermal efficiency, good dispersibility etc., has emerged as a preferred material for high‐performance thermal actuators. However, single actuators struggle to achieve complex tasks realized by intelligent robotic systems. Herein, a bioinspired dynamic matrix is presented utilizing the developable structure of MXene‐cellulose nanofibers (CNF) soft actuators. The inclusion of CNF considerably bolsters the mechanical properties of MXene. The MXene‐CNF film possessed a higher working strain range (≈14%) than pure MXene film (≈2%). The designed developable structures complete the actuating movements. The sensing layer integration with the actuating layer led to an extremely low touch detection limit (0.3 kPa) and expedited actuating‐feedback due to the interaction between contact charging and electrostatic induction. A responsive dynamic matrix containing 3 × 3 soft actuators, completed with a close‐looped sensing‐feedback function, is developed similar to the behavior of the mimosa plant. This mimosa‐inspired dynamic matrix is capable of identifying the source of touch stimuli and providing immediate feedback. This research broadens the potential for enhancing adaptability and intelligence of soft robotic system.

Dynamic threat-reward neural processing under semi-naturalistic ecologically relevant scenarios.

Studies of affective neuroscience have typically employed highly controlled, static experimental paradigms to investigate the neural underpinnings of threat and reward processing in the brain. Yet our knowledge of affective processing in more naturalistic settings remains limited. Specifically, affective studies generally examine threat and reward features separately and under brief time periods, despite the fact that in nature organisms are often exposed to the simultaneous presence of threat and reward features for extended periods. To study the neural mechanisms of threat and reward processing under distinct temporal profiles, we created a modified version of the PACMAN game that included these environmental features. We also conducted two automated meta-analyses to compare the findings from our semi-naturalistic paradigm to those from more constrained experiments. Overall, our results revealed a distributed system of regions sensitive to threat imminence and a less distributed system related to reward imminence, both of which exhibited overlap yet neither of which involved the amygdala. Additionally, these systems broadly overlapped with corresponding meta-analyses, with the notable absence of the amygdala in our findings. Together, these findings suggest a shared system for salience processing that reveals a heightened sensitivity toward environmental threats compared to rewards when both are simultaneously present in an environment. The broad correspondence of our findings to meta-analyses, consisting of more tightly controlled paradigms, illustrates how semi-naturalistic studies can corroborate previous findings in the literature while also potentially uncovering novel mechanisms resulting from the nuances and contexts that manifest in such dynamic environments.

From salt water to bioceramics: Mimic nature through pressure-controlled hydration and crystallization.

Modern synthetic technology generally invokes high temperatures to control the hydration level of ceramics, but even the state-of-the-art technology can still only control the overall hydration content. Magically, natural organisms can produce bioceramics with tailorable hydration profiles and crystallization traits solely from amorphous precursors under physiological conditions. To mimic the biomineralization tactic, here, we report pressure-controlled hydration and crystallization in fabricated ceramics, solely from the amorphous precursors of purely inorganic gels (PIGs) synthesized from biocompatible aqueous solutions with most common ions in organisms (Ca2+, Mg2+, CO32-, and PO43-). Transparent ceramic tablets are directly produced by compressing the PIGs under mild pressure, while the pressure regulates the hydration characteristics and the subsequent crystallization behaviors of the synthesized ceramics. Among the various hydration species, the moderately bound and ordered water appears to be a key in regulating the crystallization rate. This nature-inspired study offers deeper insights into the magic behind biomineralization.

Features of chemical elements migration in natural waters and their deposition in the form of neocrystallisations in living organisms (physico-chemical modeling with animal testing)

Relevance. An original modeling method is presented, which allows obtaining qualitatively new results in practice of ecological-geochemical and biomedical research. Aim. To obtain new data on the forms of element migration in the conditions of animal and human organism parameters by means of physicochemical modeling (PC "Selector") with verification of calculated data with the results obtained for real natural objects and animal organisms. Objects. Samples of natural waters and tissues of wild animals. Methods. Computer modeling (PC "Selector"); inductively coupled plasma mass spectrometry (ICP-MS, Agilent 7700x spectrometer) – 55 elements; atomic emission spectrometry (AES, spectrometer iCAP 7600 Duo) –- 5 macrocations; ion chromatography (IC, ion-liquid chromatograph LC-20) – 6 anions; inductively coupled plasma mass spectrometry (ICP-MS, mass spectrometer NexION 300D; scanning electron microscopes Hitachi S-3400N with Bruker X@Flash 5010 energy dispersive spectrometer. Results. By means of modeling, the authors have determined the qualitative and quantitative composition of the system "solution – crystalline substance". They took into account environmental conditions and physiological parameters of animal and human organism. Natural drinking water, gastric juice, mixture of drinking water and gastric juice were used as a solution, and crystalline substance was used as newly formed mineral phases in equilibrium with the solution. The work allowed establishing that the complexes assumed in the model experiment can be the cause of appearance of nanomineral phases of chemical elements in separate tissues of a living organism.

Organismal Function Enhancement through Biomaterial Intervention.

Living organisms in nature, such as magnetotactic bacteria and eggs, generate various organic-inorganic hybrid materials, providing unique functionalities. Inspired by such natural hybrid materials, researchers can reasonably integrate biomaterials with living organisms either internally or externally to enhance their inherent capabilities and generate new functionalities. Currently, the approaches to enhancing organismal function through biomaterial intervention have undergone rapid development, progressing from the cellular level to the subcellular or multicellular level. In this review, we will concentrate on three key strategies related to biomaterial-guided bioenhancement, including biointerface engineering, artificial organelles, and 3D multicellular immune niches. For biointerface engineering, excess of amino acid residues on the surfaces of cells or viruses enables the assembly of materials to form versatile artificial shells, facilitating vaccine engineering and biological camouflage. Artificial organelles refer to artificial subcellular reactors made of biomaterials that persist in the cytoplasm, which imparts cells with on-demand regulatory ability. Moreover, macroscale biomaterials with spatiotemporal regulation characters enable the local recruitment and aggregation of cells, denoting multicellular niche to enhance crosstalk between cells and antigens. Collectively, harnessing the programmable chemical and biological attributes of biomaterials for organismal function enhancement shows significant potential in forthcoming biomedical applications.

Review: Application of 3D Printing Technology in Soft Robots.

Soft robots, inspired by living organisms in nature, are primarily made of soft materials, and can be used to perform delicate tasks due to their high flexibility, such as grasping and locomotion. However, it is a challenge to efficiently manufacture soft robots with complex functions. In recent years, 3D printing technology has greatly improved the efficiency and flexibility of manufacturing soft robots. Unlike traditional subtractive manufacturing technologies, 3D printing, as an additive manufacturing method, can directly produce parts of high quality and complex geometry for soft robots without manual errors or costly post-processing. In this review, we investigate the basic concepts and working principles of current 3D printing technologies, including stereolithography, selective laser sintering, material extrusion, and material jetting. The advantages and disadvantages of fabricating soft robots are discussed. Various 3D printing materials for soft robots are introduced, including elastomers, shape memory polymers, hydrogels, composites, and other materials. Their functions and limitations in soft robots are illustrated. The existing 3D-printed soft robots, including soft grippers, soft locomotion robots, and wearable soft robots, are demonstrated. Their application in industrial, manufacturing, service, and assistive medical fields is discussed. We summarize the challenges of 3D printing at the technical level, material level, and application level. The prospects of 3D printing technology in the field of soft robots are explored.

Diurnal variation in genetic parameters for locomotor activity in Drosophila melanogaster assessed under natural thermal conditions.

In nature, organisms are exposed to variable and occasionally stressful environmental conditions. Responses to diurnal and seasonal fluctuations, such as temperature and food accessibility, involve adaptive behavioural and physiological changes. While much work has been done on understanding the genetic architecture and evolutionary potential of stress tolerance traits under constant thermal conditions, there has been less focus on the quantitative genetic background in variable environments. In this study, we use the Drosophila Genetic Reference Panel (DGRP) to investigate the locomotor activity, a key behavioural trait, under variable natural thermal conditions during the summer in a temperate environment. Male flies from 100 DGRP lines were exposed to natural thermal and light conditions in Drosophila activity monitors across three experimental days. We found that activity was highly temperature and time dependent and varied between lines both within and between days. Furthermore, we observed variation in genetic and environmental variance components, with low to moderate estimates of the heritability for locomotor activity, consistently peaking in the afternoons. Moreover, we showed that the estimated genetic correlations of locomotor activity between two time points decreased, as the absolute differences in ambient temperature increased. In conclusion, we find that the genetic background for locomotor activity is environment specific, and we conclude that more variable and unpredictable future temperatures will likely have a strong impact on the evolutionary trajectories of behavioural traits in ectotherms.

Bioinspired Stretchable Polymers for Dynamic Optical and Thermal Regulation

Elaborated optical and thermal modulatory systems are of great importance to the survival and evolution of organisms in nature. Inspired by these natural intelligent systems, researchers have made great efforts for developing stretchable polymers and exploring their applications in fields of communication, dynamic camouflage, thermal management, and others. Herein, an up‐to‐date account of the advancements in bioinspired stretchable polymers for dynamic optical and thermal regulation is provided. First, stretchable polymers for dynamic structural colors are presented, including cholesteric liquid crystal elastomers, photonic crystal elastomers, and emerging photonic polymers. Then stretchable polymers for dynamic infrared emissivity are introduced, which are achieved by stretch‐induced wrinkled‐flat surface or stretch‐induced cracked surface. Third, stretchable polymers for dynamic thermal management are discussed, focusing on tunable solar transmittance and dynamic radiative cooling. Moreover, the perspectives on the opportunities and challenges for future research directions of bioinspired stretchable polymers are presented at the end.

Transparent Structures with a Fast De‐Stiffening Functionality

The majority of natural organisms interact with their environments with a degree of mechanical adaptability that allows them to carry out a variety of tasks and adapt to changing circumstances. Human‐made structures, however, lack this versatility and are normally designed to fulfill a certain load‐carrying requirement. This causes limitations in performance, efficiency, and safety. The aim of this article is to present rapid de‐stiffening in the response of conventional structures, without compromising the load‐bearing capacity. This has been achieved by developing an active interface using an interconnected nanostructured metallic network. A very fast heating rate with an average of ≈45 °C s−1 under 4.8 V excitation while retaining transparency of 67% is demonstrated. The embedded metallic network in a thermoplastic matrix has been deployed as an active interface, in a conventional transparent multilayered structure. Upon activation, it provides a rapid (i.e., 2 s after activation) mechanical de‐stiffening capability. The results from finite element modeling have been found to be in good agreements with those from experiments. The rapid reversible stiffness tuning demonstrated here can be implemented in variety of multilayered structures with a wide range of applications in robotics, morphing and deployable structures, active damping, and active impact safety systems.

Coordinated suction and blowing of a cylinder array for thrust generation

Various systems of mechanical devices and natural organisms use the repeated expansion and contraction of deformable structures to draw in and blow out fluid. Instead of such deformable continuous structures, a system that consists of multiple discrete bodies can also generate a directional flow through the cooperative movement of the individual bodies. In this study, we numerically investigate the collective effects of a multi-body system composed of eight circular cylinders, each of which oscillates separately in the radial direction to generate thrust. The cylinder array performs cooperative motion regulated by three motion parameters: phase difference, oscillation amplitude and frequency at a low Reynolds number ( $Re = 10$ ). The phase difference between the cylinders is critical in determining the extent of the directional flow and the time-averaged thrust. The optimal phase difference that yields the maximum time-averaged thrust is consistent, regardless of the oscillation amplitude and frequency. However, the thrust generation performance becomes significantly weaker at a higher Reynolds number ( $Re = 100$ ). This highlights that the hydrodynamic blockage in gaps between cylinders, which is induced by strong viscous diffusion at the low Reynolds number, is essential for the cooperative force generation of multiple closely spaced bodies. A new dimensionless geometric parameter based on the motion of the array is proposed to characterize the degree of bias in the generated flow and it successfully predicts the trend in the time-averaged thrust at the low Reynolds number with strong hydrodynamic blockage.

Possible anti-fouling effect of polyenes in molluscs shell

Polyenes were analysed in two species of marine gastropods (the periwinkles Littorina brevicula and Littorina mandshurica) and two species of marine bivalves (the mussels Mytilus trossulus and Crenomytilus grayanus) to determine the relationship of these compounds with the fouling of molluscs shell. It was found that the shells of the Littorina gastropods and M. trossulus, which are rarely overgrown by fouling organisms in nature, contained polyenes. In rare cases of fouling by Balanus barnacles, there were no polyenes at the sites of their attachment on the shells. Polyenes were not found in the shells of C. grayanus, which are often prone to fouling. The role of polyenes in the possible anti-fouling properties of molluscan shells is discussed.

Biomimetic Adaptive Pure Pursuit Control for Robot Path Tracking Inspired by Natural Motion Constraints.

The essence of biomimetics in human-computer interaction (HCI) is the inspiration derived from natural systems to drive innovations in modern-day technologies. With this in mind, this paper introduces a biomimetic adaptive pure pursuit (A-PP) algorithm tailored for the four-wheel differential drive robot (FWDDR). Drawing inspiration from the intricate natural motions subjected to constraints, the FWDDR's kinematic model mirrors non-holonomic constraints found in biological entities. Recognizing the limitations of traditional pure pursuit (PP) algorithms, which often mimic a static behavioral approach, our proposed A-PP algorithm infuses adaptive techniques observed in nature. Integrated with a quadratic polynomial, this algorithm introduces adaptability in both lateral and longitudinal dimensions. Experimental validations demonstrate that our biomimetically inspired A-PP approach achieves superior path-following accuracy, mirroring the efficiency and fluidity seen in natural organisms.

Engineering of Ogataea polymorpha strains with ability for high-temperature alcoholic fermentation of cellobiose.

Successful conversion of cellulosic biomass into biofuels requires organisms capable of efficiently utilizing xylose as well as cellodextrins and glucose. Ogataea (Hansenula) polymorpha is the natural xylose-metabolizing organism and is one of the most thermotolerant yeasts known, with a maximum growth temperature above 50°C. Cellobiose-fermenting strains, derivatives of an improved ethanol producer from xylose O.polymorpha BEP/cat8∆, were constructed in this work by the introduction of heterologous genes encoding cellodextrin transporters (CDTs) and intracellular enzymes (β-glucosidase or cellobiose phosphorylase) that hydrolyze cellobiose. For this purpose, the genes gh1-1 of β-glucosidase, CDT-1m and CDT-2m of cellodextrin transporters from Neurospora crassa and the CBP gene coding for cellobiose phosphorylase from Saccharophagus degradans, were successfully expressed in O. polymorpha. Through metabolic engineering and mutagenesis, strains BEP/cat8∆/gh1-1/CDT-1m and BEP/cat8∆/CBP-1/CDT-2mAM were developed, showing improved parameters for high-temperature alcoholic fermentation of cellobiose. The study highlights the need for further optimization to enhance ethanol yields and elucidate cellobiose metabolism intricacies in O. polymorpha yeast. This is the first report of the successful development of stable methylotrophic thermotolerant strains of O.polymorpha capable of coutilizing cellobiose, glucose, and xylose under high-temperature alcoholic fermentation conditions at 45°C.

Redefining Consciousness

This Paper examined hot topics of Consciousness, emergence, supervenience, terrestrial planets, fine tuning of earth, the Goldilocks, and the concept of dualism, all of which physicists now consider worthy of scientific inquiry. Analysis of these topics led to many findings namely, how the earth acquired high level of fine tuning (from the Sun’s energy) while earth’s three terrestrial neighbors Mercury, Venus, and Mars, failed to achieve fine tuning as reason there is life on Earth, but there is no life on other three terrestrial planets. This Paper examined the Goldilocks and found earth’s central position in the Goldilocks as the main reason earth alone acquired favorable fine tuning for life to appear on earth. This Paper has traced the origin of Consciousness to the concept of emergence. This Paper found that Consciousness is an emergent property of a fine-tuned earth. Hence, Consciousness is not fundamental. This research has answered one of the most fundamental questions about Consciousness that; Consciousness is not monist but dual. Consciousness consists of two different and opposite parts namely, Cosmic Consciousness and Objective Consciousness. Objective consciousness is the type of consciousness derived from the brain known to physicists, psychologists, neuroscientists, and everyone else. This Paper found that dualism and dual Consciousness underpins every living organism in nature through the dual principles of Opposites and Complementarity of opposites such as, matter/energy, body/mind, male/female. Hence, the Supremacy of Dualism prevails. This Paper examined supervenience and how Consciousness supervenes matter similar to how magnet supervenes a loadstone.

Nature-inspired adhesive systems.

Many organisms in nature thrive in intricate habitats through their unique bio-adhesive surfaces, facilitating tasks such as capturing prey and reproduction. It's important to note that the remarkable adhesion properties found in these natural biological surfaces primarily arise from their distinct micro- and nanostructures and/or chemical compositions. To create artificial surfaces with superior adhesion capabilities, researchers delve deeper into the underlying mechanisms of these captivating adhesion phenomena to draw inspiration. This article provides a systematic overview of various biological surfaces with different adhesion mechanisms, focusing on surface micro- and nanostructures and/or chemistry, offering design principles for their artificial counterparts. Here, the basic interactions and adhesion models of natural biological surfaces are introduced first. This will be followed by an exploration of research advancements in natural and artificial adhesive surfaces including both dry adhesive surfaces and wet/underwater adhesive surfaces, along with relevant adhesion characterization techniques. Special attention is paid to stimulus-responsive smart artificial adhesive surfaces with tunable adhesive properties. The goal is to spotlight recent advancements, identify common themes, and explore fundamental distinctions to pinpoint the present challenges and prospects in this field.

Guidelines derived from biomineralized tissues for design and construction of high-performance biomimetic materials: from weak to strong.

Living organisms in nature have undergone continuous evolution over billions of years, resulting in the formation of high-performance fracture-resistant biomineralized tissues such as bones and teeth to fulfill mechanical and biological functions, despite the fact that most inorganic biominerals that constitute biomineralized tissues are weak and brittle. During the long-period evolution process, nature has evolved a number of highly effective and smart strategies to design chemical compositions and structures of biomineralized tissues to enable superior properties and to adapt to surrounding environments. Most biomineralized tissues have hierarchically ordered structures consisting of very small building blocks on the nanometer scale (nanoparticles, nanofibers or nanoflakes) to reduce the inherent weaknesses and brittleness of corresponding inorganic biominerals, to prevent crack initiation and propagation, and to allow high defect tolerance. The bioinspired principles derived from biomineralized tissues are indispensable for designing and constructing high-performance biomimetic materials. In recent years, a large number of high-performance biomimetic materials have been prepared based on these bioinspired principles with a large volume of literature covering this topic. Therefore, a timely and comprehensive review on this hot topic is highly important and contributes to the future development of this rapidly evolving research field. This review article aims to be comprehensive, authoritative, and critical with wide general interest to the science community, summarizing recent advances in revealing the formation processes, composition, and structures of biomineralized tissues, providing in-depth insights into guidelines derived from biomineralized tissues for the design and construction of high-performance biomimetic materials, and discussing recent progress, current research trends, key problems, future main research directions and challenges, and future perspectives in this exciting and rapidly evolving research field.

Bioinspired multi-scale interface design for wet gas sensing based on rational water management.

Natural organisms have evolved multi-scale wet gas sensing interfaces with optimized mass transport pathways in biological fluid environments, which sheds light on developing artificial counterparts with improved wet gas sensing abilities and practical applications. Herein, we highlighted current advances in wet gas sensing taking advantage of optimized mass transport pathways endowed by multi-scale interface design. Common moisture resistance (e.g., employing moisture resistant sensing materials, post-modifying moisture resistant coatings, physical heating for moisture resistance, and self-removing hydroxyl groups) and moisture absorption (e.g., employing moisture absorption sensing materials and post-modifying moisture absorption coatings) strategies for wet gas sensing were discussed. Then, the design principles of bioinspired multi-scale wet gas sensing interfaces were provided, including macro-level condensation mediation, micro/nano-level transport pathway adjustment and molecular level moisture-proof design. Finally, perspectives on constructing bioinspired multi-scale wet gas sensing interfaces were presented, which will not only deepen our understanding of the underlying principles, but also promote practical applications.

Bioinspired microrobots and their biomedical applications.

Natural organisms and biological systems provide a rich source of inspiration for the development of bioinspired microrobots. These diminutive automatons, designed to emulate the intricate structures and functions of living entities, extend human capabilities across a spectrum of applications. This review endeavors to amalgamate and elucidate the underpinnings of such bioinspired microrobots design, traversing the interdisciplinary expanse of research. It delineates a spectrum of biomedical applications for bioinspired microrobots, encompassing targeted drug delivery, cellular manipulation, and minimally invasive surgical procedures, among others. Moreover, the current technical challenges and future directions of bioinspired microrobots in the biomedical field are discussed. The objective is to impart a holistic view to the readership, illuminating the significance of bioinspired microrobots in contemporary biomedicine and charting potential trajectories of innovation.

Bionic dual-scale structured films for efficient passive radiative cooling accompanied by robust durability.

Passive radiative cooling (PRC), as an energy-free cooling approach, is ingeniously harnessed for certain natural organisms to withstand extreme high-temperature climates, which has inspired numerous bionic designs. However, it is a great challenge to enhance the durability of the designed materials in practical scenarios while inheriting the natural biological principles. We demonstrate bionic dual-scale structured (BDSS) films for efficient passive radiative cooling accompanied by robust durability after discovering the excellent thermoregulatory properties of the inner surface of Hawaiian scallop shell. We found that the inner surface of the shell consists of large-scale triangular ridges scattered with small-scale terrace steps. This dual-scale structure can enhance the reflectivity of sunlight by efficient Mie scattering and increase the emissivity in the mid-infrared range by lengthening the propagation of photons, thereby decreasing the surface temperature. Underpinned by this finding, we developed a BDSS film that features a strong solar spectrum reflectivity of 0.95 and a high mid-infrared emissivity of 0.98, achieving a sub-ambient cooling of 10.8 °C under direct sunlight. Additionally, the designed films possess robust durability including excellent self-cleaning, flexibility, mechanical strength, chemical stability, and anti-ultraviolet radiation, which is promising for thermal thermoregulation in various harsh scenarios.

Biomimicry: Journey to the Future with the Power of Nature

Biomimicry involves studying and imitating nature's strategies and features in man-made design and technology. This approach fosters innovation in industrial, scientific, and design projects, drawing inspiration from the exceptional adaptations, processes, and structures of organisms. The primary goal of biomimicry is to comprehend the complexity and efficiency of natural ecosystems, leveraging this understanding to develop sustainable technologies and utilize natural resources more effectively. While humans have drawn inspiration from nature for thousands of years, the modern term gained popularity in the mid-20th century. Biomimicry is integral to sustainability, offering solutions in harmony with nature by integrating its balances into man-made systems. In medicine, biomimicry taps into the characteristics and processes of natural organisms to inspire innovative treatment methods and materials. In education, it equips students with the skills to comprehend and replicate nature responsibly, inspiring future designers and scientists. Ethical considerations emphasize that learning from nature should occur without causing harm to the natural environment. To unlock its full potential, biomimicry requires broader acceptance, integration into industrial applications, and technological advances for sustainable resource use. The energy sector, for instance, can benefit from biomimicry by enhancing the efficiency of solar panels through inspiration from photosynthesis, offering environmentally friendly energy production solutions. In essence, biomimicry is the key to discovering sustainable, innovative, and ethical solutions inspired by nature. As we delve into the richness of the natural world, this approach plays a pivotal role in shaping future technology and design. This review focuses on current biomimicry research, particularly highlighting its potential in the energy sector. The paper aims to serve as a blueprint for future achievements while shedding light on the unseen limitations of biomimicry.