Bioinspiration’s success requires straightforward access to biological data in a form that non-biologists can understand. In this poster, we present a new tool, "Bioinspire-Explore", which allows biomimicry practitioners to delve into global biodiversity data via a user-friendly interface (Saint-Sardos et al., 2024). Through this exploration, stakeholders can uncover biological models potentially relevant to a range of bioinspired fields and sectors. Bioinspire-Explore’s entry point is a taxon of interest (i.e. species, genus, family, etc.) connecting the user to information regarding its position in the phylogenetic "tree of life", its distribution and climatic niche, as well as its appearance. This is achieved through linking Bioinspire-Explore to international databases, namely the Global Biodiversity Information Facility GBIF (based on the Catalogue of Life taxonomic backbone), WordClim, Wikidata, and INaturalist. Aside from presenting this fundamental biological and ecological information through a single interface, Bioinspire-Explore also allows users to assess the semantic proximity of relevant entities within a corpus of scientific literature pertaining to bioinspiration/biomimicry. This supports bioinspired design by offering potential connections between a taxon and its associated biological functions, environment, or physical characteristics. Bioinspire-Explore thus provides a unique way to explore biodiversity data and visualise biological relationships. This innovative tool acts as a guide, not a replacement for the active involvement of biologists in bioinspiration projects. Rather, it orientates the user towards promising information regarding living systems of interest and presents those systems in their scientific context. It is intended to create opportunities for education, insight, and interaction within bioinspiration teams interested in a “biology-push” approach to innovation.

Global population growth, environmental degradation, climate change, and geopolitical issues are putting pressure on sectors like agriculture, forestry, water management, environmental protection, and biodiversity preservation, making the sustainable use of the environment a growing challenge. The potential uses of biomimetic sensors in agriculture and other sectors have drawn a lot of interest in recent years. Despite extensive research on biomimetic sensors in general, a comprehensive analysis of their unique applications and developments in agriculture is still lacking. Hence, this paper aims to provide a comprehensive understanding of the future advancement and application of biomimetic sensors' potential in various sectors, highlighting their potential in agriculture. Through synthesizing the available literature from the last 10 years, this paper delves into the integration of biomimetic sensors in agricultural practices, highlighting potential benefits and identifying current limitations, challenges, and construction. It will encourage researchers, experts, and industry professionals to explore new ways to enhance biomimetic sensor capabilities in the agricultural sector. This review suggests that biomimetic sensors in agriculture require further studies to develop advanced technologies, optimize design, enhance capabilities, and functionality, and integrate fields like biology, materials science, and engineering. Integrating data analytics and machine learning could lead to precision agriculture and real-time crop health monitoring.

Landing on vertical surfaces poses a greater challenge for insects compared to horizontal ones, yet it remarkably expands their spatial range. Butterflies, adept at perching vertically, offer a compelling bio-inspired model. However, the mechanisms behind their landing behavior and the associated perceptual processes on vertical surfaces remain elusive. Similar to takeoff, understanding the distinctive strategies employed by butterflies during vertical landings is imperative. This encompasses the dynamics of self-stability, the role of visual perception in posture control, and the influence of asymmetric wing flapping on posture changes.
This research employs a high-speed camera system to comprehensively track the descent process of butterflies onto vertical surfaces. This study successfully captures a sequence of coordinated behaviors involved in wall landings. Kinematic analysis reveals the ability of butterflies to maintain body stability despite significant pitch rate variations. This suggests that, beyond flight mechanics, butterflies exhibit robust control over body posture influenced by other factors. Drawing on insect optic flow perception during landing, this study proposes three primary visual cues influencing butterfly landing behavior. Correlation analysis establishes connections between butterfly rotational maneuvers and visual cues. Finally, by delineating the asymmetrical differences in wing Euler angle changes, the corresponding relationships with posture angle variations are identified.

Introduction: Many avian species are well equipped for dynamic flight with flexible morphing wings and tails that optimize aerodynamic performance across various environmental conditions. As a result, imitating the shape-changing anatomical characteristics of birds can result in unmanned aerial vehicle (UAV) designs that outperform conventional fixed-wing UAVs in terms of flight performance. This rationale is the guiding principle behind the research on morphing aerospace structures. Methods: This work presents CGull, a bio-inspired, non-flapping UAV with wing- and tail-morphing capabilities. CGull’s target weight and size are based on the characteristics of the Great Black-Backed Gull (GBBG). A mathematical model was first developed in MachUpX to guide the selection of the design parameters for optimal performance at various morphing configurations. Only one morphing degree of freedom (DOF) was used in CGull’s wing, which bends the inner wing forward and the feathered outer wing backward, replicating the seagull’s wing deformation. A compact design of an actuation mechanism was proposed to control three DOFs in the tail: pitching, tilting, and feather expansion. Laminated composite structures were utilized in various components, such as the outer shell of the central body and the feathers. Computational fluid dynamics (CFD) and finite element analysis (FEA) simulations were performed to validate the design choices. Results: A proof-of-concept prototype was built, and various tests were performed to prove the effectiveness of the proposed design. Conclusions: The proposed bio-inspired morphing UAV design can replicate the GBBG’s non-flapping flight effectively. The selected composite materials and servomotors enabled us to achieve the design objectives.

Hummingbirds and insects can hover in disturbed conditions, escape from predators with a very fast response, fly for miles without landing, etc. These outstanding features are still unmatched by the most recent bio-inspired drones, due to complex aerodynamic phenomena that are underexploited by flapping wings. We propose an innovative control framework that blends model-free and model-based strategies to control the wing kinematics of Flapping Wing Micro Air Vehicles (FWMAVs) in a “take-off and hover” scenario.
The control strategy reunites a Reinforcement Learning approach (Deep Deterministic Policy Gradient), that mimics the trial-and-error learning process of natural species and an adjoint-based approach that interacts with a calibrated model of the environment. The approaches collaborate and learn from each other to be robust to highly dynamic maneuvers and sample-efficient. The approach is tested on a canonical drone formed of a spherical body and two semi-elliptical, rigid wings that operate within the hummingbird’s range. The drone flight is simulated combining the equations of motion with a data-driven, quasi-steady model that estimates the wing aerodynamic forces. The controller adapts those forces by varying the wing motion, parametrized by three degrees of freedom, to reach the flight objective and satisfy an energy-minimization constraint.
The results show that the drone efficiently reaches its target thanks to the complex adaptation of its wing kinematics. The physics of the flight was also analyzed thanks to a high-fidelity CFD environment. This contribution thus shows a first proof of concept of a control algorithm that aims to bridge the gap between natural flyers and bio-inspired drone flight maneuvers.

Introduction: The most common back and neck discomfort is closely linked to the dysfunction of intervertebral discs (IVDs) as they undergo degeneration. Intervertebral discs (IVDs) are composed of three distinct structures, namely the nucleus pulposus (NP), the annulus fibrosus (AF), and vertebral end-plates (VEP). With advancing age, there is a decrease in the water content of the NP, resulting in the accumulation of mechanical loads on the annulus. Consequently, the NP experiences wear and cracking, leading to an ensuing inflammatory reaction and the occurrence of a prolapsed intervertebral disc.

Methods: Current therapeutic approaches for degenerative disc disease provide pain relief or partially restore the native functions of IVDs. The application of biomimetic materials in tissue engineering represents a new strategy to restore the structure and function of IVDs. Nanofiber scaffolds are widely utilized in the engineering of soft orthopedic tissues such as intervertebral discs due to their extensive surface area, structural similarities to components of the extracellular matrix, capacity to deliver bioactive signals, flexibility in polymer selection, and cost-effective fabrication methods. Fabricated IVDs must simulate the structure of native discs. Long-term implantation should show good shape maintenance, hydration, integration with surrounding tissues, and mechanical support and flexibility.

Results and Conclusions: Biodegradable nanofibers can carry anti-inflammatory drugs and cytokines for gradual release, aiding in healing and preventing inflammation. Synthetic scaffolds loaded with bioactive materials, stem cells, and growth factors can support IVDs for long-term cure. The use of natural materials like silk with textile design features can imitate IVD structure, providing cytocompatibility, biodegradability, high strength, and stiffness in tension and compression. Nanofiber-based scaffolds, with their extraordinary properties, provide researchers with the opportunity to design scaffolds that can mimic the morphological and mechanical properties of native IVDs.

The flight muscles of birds and bats actively control wing deformations, while insect wings rely mainly on passive mechanisms determined by their adaptive wing structures. This study delves into the unique design of insect wings, specifically focusing on the 3D component known as the basal complex situated in the wing's proximal region. Our research, employing a comprehensive array of multidisciplinary methods, including modern imaging techniques, mechanical testing, finite element analysis, parametric modelling, conceptual design, and 3D printing, rigorously tests the hypothesis that the basal complex plays a pivotal role in determining the quality and quantity of wing deformations during flight. The results support this hypothesis, revealing that variations in the basal complex's material and structural design elements among dragonfly and damselfly species lead to significant differences in symmetric or asymmetric deformation patterns observed in insect wings in flight. Our systematic investigation of geometric parameters in a set of numerical models further indicates adaptations for achieving maximum camber under loading. Inspired by the basal complex, we introduce a shape-morphing mechanism applicable to wind turbine blades, simplifying actuation and control systems. This research not only contributes to understanding the biomechanics of complex insect wings but also offers valuable insights for engineering shape-morphing systems with enhanced mechanical intelligence and simplified control requirements.

Introduction: Bacteria belonging to the Legionella gormanii species cause respiratory diseases. The key factor in the proper functioning and virulence of these microorganisms is the structure of biological membranes, the main components of which are phospholipids (PL). Their composition in the outer membrane layer of L. gormanii cells can change under various environmental factors, such as the presence of choline in the growth medium. Phospholipid distribution, the quantitative proportions of individual classes and intermolecular interactions define the physicochemical properties of bacterial membranes. The aim of the present research was the thermodynamic analysis of interactions occurring in model L. gormanii membranes with different phospholipid compositions.

Methods: Model membranes were created by means of the Langmuir monolayer technique using phospholipids isolated from bacteria grown with (PL+choline) and without (PL-choline) the addition of choline. To characterize the interactions between PL molecules in mixed monolayers, model single-component membranes of representatives of specific phospholipids classes were analyzed. The dependencies of surface pressure on mean molecular area (π-A isotherms) were obtained. Based on experimental data, the excess area A_exc and excess Gibbs energy of mixing ΔG_exc were determined.

Results: The PL-choline membrane, due to its higher content of anionic phospholipids, is characterized by stronger repulsive interactions, while the PL+choline membrane, containing mostly zwitterionic compounds, shows stronger attractive interactions in comparison to single-component monolayers. The increase in repulsive interactions between PL-choline molecules results in greater flexibility of the membrane and limited miscibility of the components. On the contrary, the increase in attractive forces in PL+choline causes the formation of more homogeneous and tightly packed membranes.

Conclusions: The determination of interactions occurring in bacterial membranes and their changes induced by external factors can contribute to the development of new methods of treating infections caused by L. gormanii.

Introduction

The stiffness of a tissue changes during the lifetime of an individual and is an indicator of age, disease, and pathophysiological conditions. Increased tissue stiffness is a hallmark of illnesses like cancer and cardiovascular diseases, causing major mortality worldwide. Cells interact with the mechanical cues of the surrounding ECM by adjusting themselves through communication from the nanometer to the meter scale by rearranging their cytoskeleton, nuclear envelope structure and composition, and migration. Understanding how forces work will unlock new avenues in disease research, regenerative medicine, and the design of implantable biomaterials.

Materials and methods

A 3D silk fibroin biomaterial library is created with diverse mechanical stiffness ranging from ~3 kPa to 0.4 kPa.

Results

The cell–cell and cell–ECM interactions in this dynamic niche are evaluated using stem cells. The up- or down-regulation of certain genes with ECM stiffness acts as a marker of cellular response to dynamic mechanical ECM, while cell-mediated mineralization is indicative of cell–cell and cell–ECM crosstalk.

Conclusion

This study also confirms that biomimetic, dynamic ECM-mediated physical cues not only influence the differentiation behavior of the cells but also regulate the migration of surrounding cells toward the engineered niche. However, further investigation is needed.

Acknowledgments

This work is supported by SERB-DST (SRG/2022/000563/LS), the Government of India (B.K.). The author is thankful to the I3Bs, Research Institute on Biomaterials, Biodegradables, and Biomimetics, University of Minho, Portugal, for the infrastructure support.

Animals such as chameleons change their skin colour in case of potential threat and recover damaged tissues [1]. Some ferrocenyl-containing polymers are similar to chameleon skin in terms of its colour-changing behaviour. For instance, they exhibit electrochromic properties due to easy reversible one-electron redox transition [2].

Another feature of chameleons represented in polymer materials is their self-healing ability. One of the most promising self-healing materials is silicone rubber [3]. Some silicone materials possess self-healing properties achieved through siloxane equilibrium. This mechanism is based on reversible interactions between “living” anionic centres and polysiloxane chains [2,3].

The siloxane equilibrium discussed above allowed us to prepare unique chameleon-like ferrocenyl-containing silicone rubbers (FSRs) which exhibit both electrochromic and self-healing properties [2]. Thus, FSRs were obtained through ring-opening anionic copolymerisation of cyclic siloxane monomers including octamethylcyclotetrasiloxane (D₄), tetraferrocenyl-substituted cyclotetrasiloxane (1,3,5,7-(2-ferrocenylethyl)-1,3,5,7-tetramethylcyclotetrasiloxane, Fc₄D₄), and bicyclic cross-linking agent (bis-D₄). The physicochemical properties of the FSRs were estimated by tensile tests and cyclic voltammetry. As a result, the tensile strength of the FSRs reached 0.1 MPa, and elongation at break was 215%. After one hour, the recovery of FSR self-healing efficiency at 25 and 100 °C reached 98%. The FSRs also possess redox activity (Fc/Fc⁺ transformations at E⁰ = 0.43 V) and electrical conductivity at the level of antistatic materials (approximately 10^–10 S cm^–1). The FSR films change their colour from yellow (reduced state) to blue (oxidised state). Our chameleon-inspired materials could find potential application as redox-active and flexible electrochromic coatings.

This research was funded by the Russian Science Foundation (№ 23-23-00103).

References:

1. Zheng, R. et al. // ACS Appl. Mater. Interfaces 2018, 10, 35533–35538, doi:10.1021/acsami.8b13249.
2. Rashevskii, A.A. et al. // Coatings 2023, 13, 1282, doi:10.3390/coatings13071282.
3. Deriabin, K.V. et al. // Biomimetics 2023, 8, 286, doi:10.3390/biomimetics8030286.