Biomimetic Design and Optimal Swing of a Hexapod Robot Leg

Biological inspiration has spawned a wealth of solutions to both mechanical design and control schemes in the efforts to develop agile legged machines. This paper presents a compliant leg mechanism for a small six-legged robot, HITCR-ll, based on abstracted anatomy from insect legs. Kinematic structure, relative proportion of leg segment lengths and actuation system were analyzed in consideration of anatomical structure as well as muscle system of insect legs and desired mobility. A spring based passive compliance mechanism inspired by musculoskeletal structures of biological systems was integrated into distal segment of the leg to soften foot impact on touchdown. In addition, an efficient locomotion planner capable of generating natural movements for the legs during swing phase was proposed. The problem of leg swing was formulated as an optimal control procedure that satisfies a series of locomotion task terms while minimizing a biologically-based objective function, which was solved by a Gauss Pseudospectral Method （GPM） based numerical technique. We applied this swing generation algorithm to both a simulation platform and a robot prototype. Results show that the proposed leg structure and swing planner are able to successfully perform effective swing movements on rugged terrains.

Effects of Biomimetic Surface Designs on Furrow Opener Performance

The effects of biomimetic designs of tine furrow opener surface on equivalent pressure and pressure in the direction of motion on opener surface against soil were studied by finite element method (FEM) simulation and the effects of these designs on tool force and power requirements were examined experimentally.Geometrical structures of the cuticle surfaces of dung beetle (Copris ochus Motschulsky) were examined by stereoscopy.The structures of the cuticle surfaces and Ultra High Mo- lecular Weight Polyethylene (UHMWPE) material were modeled on surface of tine furrow opener as biomimetic designs.Seven furrow openers were analyzed in ANSYS program (a FEM simulation software).The biomimetic furrow opener surfaces with UHMWPE structures were found to have lower equivalent pressure and pressure in the direction of motion as compared to the conventional surface and to the biomimetic surfaces with textured steel-35 structures.It was found that the tool force and power were increased with the cutting depth and operating speed and the biomimetic furrow opener with UHMWPE tubular section ridges showed the lowest resistance and power requirement against soil..

A bionic controllable strain membrane for cell stretching at air–liquid interface inspired by papercutting

Lung diseases associated with alveoli,such as acute respiratory distress syndrome,have posed a long-term threat to human health.However,an in vitro model capable of simulating different deformations of the alveoli and a suitable material for mimicking basement membrane are currently lacking.Here,we present an innovative biomimetic controllable strain membrane(BCSM)at an air–liquid interface(ALI)to reconstruct alveolar respiration.The BCSM consists of a high-precision three-dimensional printing melt-electrowritten polycaprolactone(PCL)mesh,coated with a hydrogel substrate—to simulate the important functions(such as stiffness,porosity,wettability,and ALI)of alveolar microenvironments,and seeded pulmonary epithelial cells and vascular endothelial cells on either side,respectively.Inspired by papercutting,the BCSM was fabricated in the plane while it operated in three dimensions.A series of the topological structure of the BCSM was designed to control various local-area strain,mimicking alveolar varied deformation.Lopinavir/ritonavir could reduce Lamin A expression under over-stretch condition,which might be effective in preventing ventilator-induced lung injury.The biomimetic lung-unit model with BCSM has broader application prospects in alveoli-related research in the future,such as in drug toxicology and metabolism.

Interactive Kinetic Canopy with Industrial Architecture Legacy Preservation Approach

Architecture has long sought to improve both in terms of form,space and other elements.Meanwhile,the use of innovative techniques that enhance design is always one of the concerns in the field of design.Biomimetic and Nature-Friendly architecture have always inspired by natural organisms aims to emphasize harmony with the environment.From another approach,contemporary industrial architecture has a valuable place in this knowledge,and the restoration and preservation of this heritage is a serious subject.Using attractive methods like an integration of new technology and monumental heritage lead to a profound impact.To this end,designing a canopy using an interactive and kinetic pattern to value this theme can be effective on sustainable development goals in area.This canopy which is inspired by biomimetic pattern and natural potentials from the site,responses to external motivation and adapts its kinetic movements to follow human interactions.The innovative techniques are involved with choosing a precise geometrical frame and order,kinetic patterns suitable for the project and finally fabrication of an scale model from actual dimensions.By choosing a suitable site that houses building of contemporary industrial architecture such as a railway station,this paper aims at learning from nature to fulfill industrial heritage legacy retention that is in both physical and spiritual interaction with humans.

Bionic Volute Tongue Optimization Design of Multi-blade Centrifugal Fan Inspired by the Wave Leading-edge of Humpback Whale Flippers

The volute tongue can split the gas in the multi-blade centrifugal fan to make the gas flow to the volute outlet as much as possible.However,the unsteady axial deflection of the gas in the impeller results in different air flow angles at the outlet of the impeller at different blade heights.This seriously affects the flow near the volute tongue.The wave leading-edge structure of humpback whale flippers has a very high flow control effect under complex flow conditions.Therefore,the wave leading-edge structure is studied in this paper and applied to the optimization design of multi-blade centrifugal fan volute tongue.First,based on the wave leading-edge structure of humpback whale flippers,three-dimensional wave leading-edge airfoils with different wave direction angles are established to judge the adaptability of the new wave leading-edge structure under different attack angles.Then,aiming at the internal flow field and noise characteristics of multi-blade centrifugal fan,a bionic volute tongue optimization design method is proposed,and studied its influence on the internal flow field and noise characteristics of the fan.The results show that when the wave direction angle is 45°,the wave leading-edge structure can effectively suppress the generation of the leading-edge separation vortex and the shedding of the wake vortex,which is also helpful to reduce the noise.The bionic volute tongue with the wave leading-edge structure can adapt to the situation that the impeller outlet air flow angle is small.At the maximum volume flow rate operating point,the static pressure recovery coefficient of the bionic volute tongue fan is increased by about 5%compared to the original fan,the air volume is increased by 5.16%,and the noise is reduced by 0.6 dB.

Synovial fluid-inspired biomimetic lubricating microspheres:Zwitterionic polyelectrolyte brushes-grafted microgels

Synovial fluid is made up of various biomacromolecules,including hyaluronic acid,aggrecans,lubricins,and phosphatidylcholine lipid,which are assembled onto the surface of articular cartilage in a gel state.Among them,brush-like biomacromolecules or assemblies have a vital effect on human joint lubrication.Inspired by this,the combination of brush-like molecular structures and gel-like assembly may be an efficient approach for the synthesis of biomimetic lubricating matters.Learning from the lubrication system of human joints,poly(2-methacryloyloxyethyl phosphorylcholine)(PMPC)brushes grafted poly(N-isopropylacrylamide-co-acrylic acid)(poly(NIPAAm-co-AA))microgels,abbreviated as MBs-g-MGs,were synthesized as one kind of biomimetic lubricating additives.It is worth noting that this bionic strategy considered both molecular structure and assembled form,which enabled this hairy microgel to achieve low friction in aqueous medium.Meanwhile,the effective lubrication was still achieved when using MBs-g-MGs at high temperature,indicating that this microgel maintains a good lubricating effect over a wide range of temperature.In addition,this kind of microgel possessed good biocompatibility,which laid the foundation for potential biomedical applications.Looking beyond,these biomimetic microgels may provide an effective lubricating effect for water-based sliding interfaces,especially in biomedical systems.

Gather wisdom to overcome barriers:Well-designed nano-drug delivery systems for treating gliomas

Due to the special physiological and pathological characteristics of gliomas,most therapeutic drugs are prevented from entering the brain.To improve the poor prognosis of existing therapies,researchers have been continuously developing non-invasive methods to overcome barriers to gliomas therapy.Although these strategies can be used clinically to overcome the blood-brain barrier(BBB),the accurate delivery of drugs to the glioma lesions cannot be ensured.Nano-drug delivery systems(NDDS)have been widely used for precise drug delivery.In recent years,researchers have gathered their wisdom to overcome barriers,so many well-designed NDDS have performed prominently in preclinical studies.These meticulous designs mainly include cascade passing through BBB and targeting to glioma lesions,drug release in response to the glioma microenvironment,biomimetic delivery systems based on endogenous cells/extracellular vesicles/protein,and carriers created according to the active ingredients of traditional Chinese medicines.We reviewed these well-designed NDDS in detail.Furthermore,we discussed the current ongoing and completed clinical trials of NDDS for gliomas therapy,and analyzed the challenges and trends faced by clinical translation of these well-designed NDDS.

Robust scalable reversible strong adhesion by gecko-inspired composite design

Bio-inspired reversible adhesion has significant potential in many fields requiring flexible grasping and manipulation,such as precision manufacturing,flexible electronics,and intelligent robotics.Despite extensive efforts for adhesive synthesis with a high adhesion strength at the interface,an effective strategy to actively tune the adhesion capacity between a strong attachment and an easy detachment spanning a wide range of scales has been lagged.Herein,we report a novel soft-hard-soft sandwiched composite design to achieve a stable,repeatable,and reversible strong adhesion with an easily scalable performance for a large area ranging from~1.5 to 150 cm2 and a high load ranging from~20 to 700 N.Theoretical studies indicate that this design can enhance the uniform loading for attachment by restraining the lateral shrinkage in the natural state,while facilitate a flexible peeling for detachment by causing stress concentration in the bending state,yielding an adhesion switching ratio of~54 and a switching time of less than~0.2 s.This design is further integrated into versatile grippers,climbing robots,and human climbing grippers,demonstrating its robust scalability for a reversible strong adhesion.This biomimetic design bridges microscopic interfacial interactions with macroscopic controllable applications,providing a universal and feasible paradigm for adhesion design and control.

Computational Design and Fabrication of a Bending-Active Structure Using Fiberglass:A Bioinspired Pavilion Mimicking Marine Microorganism Radiolaria

Bio-inspired architectural designs are often superior for their aesthetics and structural performance.Mimicking forms and loading states of a biological structure is complex as it requires a delicate balance among geometry,material properties,and interacting forces.The goal of this work is to design a biomimetic,ultra-lightweight,bending-active structure utilizing an informed integral design approach,and thereby constructing a self-supporting cellular pavilion.A bioinspired pavilion has been designed and constructed based on the natural cellular organization observed in Radiolaria,a deep-sea microorganism.The cellularity was mimicked via Voronoi tessellation in the structure of the pavilion,whose structural performance was evaluated using finite element analysis.Accordingly,funicular structure design strategies were studied with a focus on cellular distributions and concentration responding to areas with high structural stress.The computer aided custom designed pavilion was constructed with engineered,in-house fabricated fiberglass composite materials.The bending-active lightweight structure was also validated through material performance inquiry,a partial full-scale cellular assembly,and the full-size pavilion construction.This work contributes to the design approach comprising a bending-active form-finding schematic strategy to construct the elastic bending-active structure physically and simulate computationally within the context of nature inspired innovative lightweight structure design.

A hierarchical bilayer architecture for complex tissue regeneration

Engineering a complete,physiologically functional,periodontal complex structure remains a great clinical challenge due to the highly hierarchical architecture of the periodontium and coordinated regulation of multiple growth factors required to induce stem cell multilineage differentiation.Using biomimetic self-assembly and microstamping techniques,we construct a hierarchical bilayer architecture consisting of intrafibrillarly mineralized collagen resembling bone and cementum,and unmineralized parallel-aligned fibrils mimicking periodontal ligament.The prepared biphasic scaffold possesses unique micro/nano structure,differential mechanical properties,and growth factor-rich microenvironment between the two phases,realizing a perfect simulation of natural periodontal hard/soft tissue interface.The interconnected porous hard compartment with a Young’s modulus of 1409.00±160.83 MPa could induce cross-arrangement and osteogenic differentiation of stem cells in vitro,whereas the micropatterned soft compartment with a Young’s modulus of 42.62±4.58 MPa containing abundant endogenous growth factors,could guide parallel arrangement and fibrogenic differentiation of stem cells in vitro.After implantation in critical-sized complete periodontal tissue defect,the biomimetic bilayer architecture potently reconstructs native periodontium with the insertion of periodontal ligament fibers into newly formed cementum and alveolar bone by recruiting host mesenchymal stem cells and activating the transforming growth factor beta 1/Smad3 signaling pathway.Taken together,integration of self-assembly and microstamping strategies could successfully fabricate a hierarchical bilayer architecture,which exhibits great potential for recruiting and regulating host stem cells to promote synergistic regeneration of hard/soft tissues.