•A miniature tool to measure the fatigue limit under high temperature conditions.•Thermo-mechanical coupled in situ fatigue testing under microscope.•Deformation behaviors and fatigue limit of micro defect under variable temperature condition.This paper focuses on the design of a thermo-mechanical coupled in situ fatigue device driven by piezoelectric actuator. The structural resonances, transient response, grip design and thermal insulation performance of the device are discussed in detail. Micro-indentations are prepared on the specimen’s surface as embedded defects, and the deformation behaviors of the indentation subjected to cyclic strain under temperature of 530 °C are investigated. Quantitative effects of the cross-sectional area of indentation, alternating displacement amplitude and temperature on the fatigue life of copper/aluminum composite specimens are obtained, respectively. The experimental results could serve as proofs to verify the feasibility of the proposed device. This paper shows a modular example that combines piezoelectric actuator and ceramic heating components to realize thermo-mechanical coupled in situ fatigue testing.

The bionic consciousness, idea, and practice opened a unique path for the progress of mankind, the development of the society, and the innovation of science and technology from the subconscious bionic activities of the ancient humans to the significant bionic designs in modern engineering. Nowadays, driven by the practical demand of human beings, bionics becomes an important factor for the sustainable development of technology. A lot of new and outstanding innovations have been produced through the effective interactions between bionics, technology, and demand. The stronger the interactions, the greater the innovation success would be. In this article, the basic factors such as the connotation, characteristics, and interactions of bionic demands, bionic models, bionic simulations, and bionic products were explained, which are the indispensable basic knowledge for improving the ability of innovation especially for the original one, realizing the design and innovation of new technology and manufacturing for better bionic products.

As a promising means, the passive porosity technology is used for the trailing-edge noise reduction of a bionic airfoil. The detailed two-dimensional Large Eddy Simulation is achieved to gain a better understanding of the prediction and passive control of trailing-edge noise source with the non-porous and porous treatment, respectively. The flow fields around the bionic airfoil indicate that the leading-edge separation causes both the noise contributors, i.e., the turbulent boundary layer and the vortex shedding. In addition, the effect of the porous trailing edge is substantiated in the distribution of the static pressure. The relevant noise also suggests a pronounced noise reduction potential in excess of 10 dB, but it has dependence on the flow resistivities. The two trailing-edge noise reduction mechanisms are characterized: (1) the suppression of the tonal vortex shedding noise; (2) the reduction of broadband turbulent boundary layer scattering noise. The findings may be used as reference in the design of silent aircraft.

•We found that the S. subcrenata shell has an anti-wear ability.•This is related to the morphology, structure and material of the shell surface.•Organic material is the principal coupling element in its anti-wear ability.•Rib morphology could be considered the secondary coupling element.•The coupled structure could be regarded as the general coupling element.As a typical natural biological mineralisation material, molluscan shells have excellent wear-resistance properties that result from the interactions amongst biological coupling elements such as morphology, structure and material. The in-depth study of the wear-resistance performance of shells and the contribution made by each coupling element may help to promote the development of new bionic wear-resistant devices. The objective of this study was to investigate the influence of surface morphology (rib distribution on the shell), structure (rib coupled with nodules) and material (organic matter) on the anti-wear performance of the molluscan Scapharca subcrenata shell. The effect and contribution of each of these biological coupling elements were systematically investigated using the comparative experiment method. All three were found to exert significant effects on the shell's wear-resistance ability, and their individual contributions to that ability were revealed. Organic material can be classified as the principal coupling element, rib morphology as the secondary coupling element and the combined rib-nodule structure as the general coupling element.

Dragonfly is one of the most excellent nature flyers, and its wings exhibit excellent functional characteristics through the coupling and synergy of morphology, configuration, structure and material. The functional characteristics presented by dragonfly wings provide an biological inspiration for the investigation and development of aerospace vehicles and bionics flapping aerocraft flapping-wing micro air vehicles. In resent years, some progresses have been achieved in the researches on the wings’ geometric structure, material characteristics, flying mechanism and the controlling mode. In this paper, the functional characteristics of the dragonfly wings including flying, self-cleaning, anti-fatigue, vibration elimination and noise reduction are introduced and the effects of their morphology, configuration, structure and material on the functional characteristics are described. Moreover, the current state of the bionic study on the functional characteristics of dragonfly wings is analyzed and its application prospect is depicted.

The mechanism of the self-propagating high temperature synthesis (SHS) processing in the Cu–Ti–C system was investigated. The reaction sequence and mechanism were explored using combustion front quenching method. The SHS reaction in the Cu–Ti–C system starts with the solid diffusion reaction between Cu and Ti particles, subsequently, the Cu–Ti liquid forms and spreads over C particles. The C particles dissolve into the Cu–Ti liquid, leading to the formation of the Cu–Ti–C ternary liquid, as a result, TiC particulates are gradually precipitated out of the liquid.Highlights► The mechanism of the SHS processing in the Cu–Ti–C system was investigated. ► The reaction sequence was explored using combustion front quenching method. ► The TiC particles formed at the interface between the liquids and the C particles.

The SHS reaction behavior of the Cu–Ti–C system with various Cu contents was investigated. The Cu addition not only serves as diluent and binder, but also plays an important role in the ignition behavior of the SHS reaction. With the increase of Cu content, the combustion temperature decreases greatly, the ignition time decreases remarkably first and increases. With the addition of 20 wt.% Cu, the system exhibits the shortest ignition time. The SHS reactions consist of two consecutive combustion stages with different brightness intensity. The two combustion stages mainly correspond to the formation of TixCuy compounds and TiC particulates, respectively. The products of the SHS reaction in the Cu–Ti–C system with various Cu contents (10–50 wt.%) consist of TiC and Cu without any intermediate phases. With the increase in the Cu reactant, the size of the TiC particulates decreases considerably.Highlights► The SHS reaction behavior of the Cu–Ti–C system was investigated. ► The Cu addition plays an important role in the ignition behavior. ► The SHS reactions consist of two consecutive combustion stages.

The study of three-dimensional human kinematics has significant impacts on medical and healthcare technology innovations. As a non-invasive technology, optoelectronic stereophotogrammetry is widely used for in-vivo locomotor evaluations. However, relatively high testing difficulties, poor testing accuracies, and high analysis complexities prohibit its further employment. The objective of this study is to explore an improved modeling technique for quantitative measurement and analysis of human locomotion. Firstly, a 3D whole body model of 17 rigid segments was developed to describe human locomotion. Subsequently, a novel infrared reflective marker cluster for 17 body segments was constructed to calibrate and record the 3D segmental position and orientation of each functional body region simultaneously with high spatial accuracy. In addition, the novel calibration procedure and the conception of kinematic coupling of human locomotion were proposed to investigate the segmental functional characteristics of human motion. Eight healthy male subjects were evaluated with walking and running experiments using the Qualisys motion capture system. The experimental results demonstrated the followings: (i) The kinematic coupling of the upper limbs and the lower limbs both showed the significant characteristics of joint motion, while the torso motion of human possessed remarkable features of segmental motion; (ii) flexion/extension was the main motion feature in sagittal plane, while the lateral bending in coronal plane and the axial rotation in transverse plane were subsidiary motions during an entire walking cycle regarding to all the segments of the human body; (iii) compared with conventional methods, the improved techniques have a competitive advantage in the convenient measurement and accurate analysis of the segmental dynamic functional characteristics during human locomotion. The modeling technique proposed in this paper has great potentials in rehabilitation engineering as well as ergonomics and biomimetic engineering.

Through rigorous natural selection, biological organisms have evolved exceptional functions highly adaptable to their living environments. Biological organisms can achieve a variety of biological functions efficiently by using the synergic actions of two or more different parts of the body, or the coupling effects of multiple factors, and demonstrate optimal adaptations to the living environment. In this paper, the function, characteristics and types of biological couplings are analyzed, the implementation mechanism and mode of biological coupling functions are revealed from the bionic viewpoint. Finally, the technological prospects of the bionic implementation of biological coupling function are predicted.

Molluscan shells are fascinating examples of highly ordered hierarchical structure and complex organic-inorganic biocomposite material. However, their anti-wear properties were rarely studied especially in the perspective of biological coupling. So in the current study three typical shells, Scapharca subcrenata, Rapana venosa and Acanthochiton rubrolineatus, were selected as coupling models to further study their anti-wear properties. Stereomicroscope and scanning electron microscopic observations showed that all these three shells had specific surface morphologies and complicated section microstructures. Importantly, a special structure, pore canal tubules, was discovered in the shells of Scapharca subcrenata and Acanthochiton rubrolineatus, which probably contributed most to their anti-wear properties. X-ray diffraction and micro-Vikers hardness tester were further adopted to analyze the phase compositions and micro-hardness of the shells. The measured results demonstrated that aragonite was the most extensive phase present in the shell, and possesed a relatively high micro-hardness. In this paper, the shells were described in details in morphology, structure and material with emphasis on the relationship with anti-wear property. The study revealed that the selected seashells possess distinct anti-wear properties by complicated mechanisms involving the integrated functions of multiple biological coupling elements, and this would provide inspiration to the design of new bionic wear resistance components.

Some kinds of particular functions possessed by natural organisms are often formed by coupling up the multiple typical features on their body surfaces. Inspired by the coupling phenomenon in biological system, the medium carbon steel specimens with the coupling effect of non-smooth mechanical property and microstructural features were fabricated by laser processing. Thermal fatigue behavior of specimens with biomimetic coupling surface was investigated and compared. The results confirmed that such a biomimetic method has the beneficial effect on improving the thermal fatigue property of medium carbon steel specimens. The related mechanisms behind the biomimetic coupling effect for explaining the enhanced thermal fatigue resistance were discussed preliminarily.

The phenomena that biological functions originate from biological coupling are the important biological foundation of multiple bionics and the significant discoveries in the bionic fields. In this paper, the basic concepts related to biological coupling are introduced from the bionic viewpoint. Constitution, classification and characteristic rules of biological coupling are illuminated, the general modes of biological coupling studies are analyzed, and the prospects of multi-coupling bionics are predicted.

The theoretical studies of bionics of machinery have great scientific significance, and the development of bionic machines has large practical values in the field of engineering and technology. Through the rigorous selection process of evolution, the survived living organisms have successfully developed outstanding abilities to adapt to their surroundings and to reproduce their offspring. In this review, we interpreted the fundamental principles of anti-adhesion and anti-resistance of soil animals by reviewing the current status in this research field and summarizing the work of the research group at Jilin University of China in the past decades. The principles and technologies used in morphology bionics, electric-osmosis bionics, flexibility bionics, configuration bionics and coupling bionics were examined. Finally, the applications of the engineering bionics and their extensive prospects were introduced.

Ti3SiC2-based compound was synthesized by mechanical alloying (MA) using starting materials consisting of 3Ti/Si/2C/xAl (x = 0, 0.1, 0.2, 0.3) powder mixtures, and the effects of Al on the MA synthesis of Ti3SiC2 were studied. Our results showed that, ball milling of the 3Ti/Si/2C powder mixture for 10 h produced both powder form products of TiC, TiSi2 and Ti3SiC2, and bulk form products with Ti3SiC2 as the main phase. Adding a small amount of Al remarkably increased the ratio of Ti3SiC2 in the mechanically alloyed products (in both the powders and the bulks). When x = 0.1, Ti3SiC2 content in the powders and bulks reached 76.8 and 85.9 wt%, respectively, after being ball milled for 10 h. Excessive Al, however, would reduce the content of Ti3SiC2 in the milled products.

The body color in animals results from billions of years of their natural evolution in order to evade natural enemies, catch quarries or display themselves beauty, investigation on mechanisms of structural light is an important aspect of bionics. Based on the phenomenon of Papilio maackii ménétriès’ blue scales changing into green ones immediately after dropping some alcohol aqua on the underwing surface and soon returning back to the original color, the relationship between microstructure, optics characteristic of scales and changing color effect were studied using the Olympus Stereomicroscope, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Ultraviolet (UV)-Visible Spectrophotometer. The color variation mechanisms of blue scales of Papilio maackii ménétriès in Chinese Northeast were revealed in this paper. When visible lights traveled through the concaver structure with multilayer reflector and the filled medium with different refractive indices, the reflected lights in definite wavelengths produced interference and color at that wavelength came into being. It has important academic reference value to biomimetics design of video stealth materials.

The principle of homology-continuity in Multi-Dimensional Biomimetic Informatics Space is applied to construct the identifying mechanism of category of deep representation of mental imagery. The model of each cerebral region involved in recognizing is established respectively and a feedforward method for establishing category mental imagery is proposed. First, the model of feature acquisition is developed based on Hubel-Wiesel model, and Gaussian function is used to simulate the simple cell receptive field to satisfy the specific function of visual cortex. Second, multiple input aggregation operation is employed to simulate the feature output of complex cells to get the invariance representation in feature space. Then, imagery basis is extracted by unsupervised learning algorithm based on the primary feature and category mental imagery is obtained by building Radial Basis Function (RBF) network. Finally, the system model is tested by training set and test set composed of real images. Experimental results show that the proposed method can establish valid deep representation of these samples, based on which the biomimetic construction of category mental imagery can be achieved. This method provides a new idea for solving imagery problem and studying imagery thinking.

Biomimetic coupling surface is a recent development in surface science of materials. One of the important methods to achieve this surface is to manufacture large numbers of structural units by certain techniques, arranging them regularly on the surface layer of materials to form the biomimetic structure. The penetration depth and the surface roughness of units are two crucial factors that affect strongly the properties of materials. In this paper, a YAG pulsed laser with varied parameters (electrical current 200 A to 300 A, pulse duration 5 ms to 15 ms, frequency 4 Hz to 10 Hz and scanning speed 0.24 mm·s−1 to 0.72 mm·s−1) was used to fabricate these units on the surface of 3Cr2W8V die steel. The penetration depth and surface roughness of the units were investigated based on orthogonal experimental design. To maximize the penetration depth and minimize the surface roughness, the range analysis and subsequently overall balance method were adopted to identify the most significant factor and level. Meanwhile the most preferable combination of the laser processing parameters was selected. The effect of laser processing parameters on the penetration depth and surface morphology of units was analyzed. The interrelationship among the processing parameters, the penetration depth and the surface roughness was discussed.

This study represents a functional analysis of the human foot complex based on in-vivo gait measurements, finite element (FE) modeling and biological coupling theory, with the objective of achieving a comprehensive understanding of the impact attenuation and energy absorption functions of the human foot complex. A simplified heel pad FE model comprising reticular fiber structure and fat cells was constructed based on the foot pad Magnetic Resonance (MR) images. The model was then used to investigate the foot pad behaviors under impact during locomotion. Three-dimensional (3D) gait measurement and a 3D FE foot model comprising 29 bones, 85 ligaments and the plantar soft tissues were used to investigate the foot arch and plantar fascia deformations in mid-stance phase. The heel pad simulation results show that the pad model with fat cells (coupling model) has much stronger capacity in impact attenuation and energy storage than the model without fat cells (structure model). Furthermore, the FE simulation reproduced the deformations of the foot arch structure and the plantar fascia extension observed in the gait measurements, which reinforces the postulation that the foot arch structure also plays an important role in energy absorption during locomotion. Finally, the coupling mechanism of the human foot functions in impact attenuation and energy absorption was proposed.

A Multi-coupling bionic steel matrix composite was fabricated using the Thermal Explosion (TE) reaction of 30 wt.% Ni-Ti-C system. The results of Scanning Electron Microscopy (SEM) and X-ray microdiffractometer investigations reveal that the reaction zone is divided into three distinct regions, i.e., Ni-TiC region, interfacial region and steel matrix region. In the Ni-TiC region, X-ray microdiffractometer tests reveal the existence of TiC and Ni phases without any intermediate phase. Observations of the interfacial regions reveal a large number of FeNi3 and a few TiC and Fe2Ti formation, which provides an essential composition gradient at the boundaries and keeps a metallurgical bonding between the Ni-TiC region and the steel matrix region. The proposed composite is hard/soft composite which combines the property of rigidity and flexibility. When it is abraded and extruded, this kind of feature shows both rigid resistance and flexible absorption. Sliding wear tests show that the wear resistance of the proposed composite is increased by about 49% in comparison with that of pure carbon steel.

Plant leaf is a natural composite biomaterial, and its strength is closely related to the microstructure. In this paper, the mechanical characteristics of eight species of plant leaves were investigated and analyzed. The ultimate strength of leaves and the hardness of leaf surfaces were measured by using universal testing machine and nanoindenter tester, respectively. The tensile strength of the parallel microstructure was investigated based on its cross-sectional mechanical model. The results of tension tests indicate that the ultimate strength of a leaf is related to the material composition and structure. The coriaceous leaves usually exhibit higher tensile strength. For example, the Phyllostachys pubescens leaf can achieve the maximum ultimate strength of 5.9091 N·mm−2. It is concluded from the results of hardness tests that material components of leaf surface can influence the surface hardness evidently. The leaf surface composed of more lignin and cellulose materials shows a higher surface hardness than that composed of more carbohydrates materials.

Mole cricket (Gryllotalpa orientalis) is a typical animal living under ground. The soil-engaging components of mole cricket have the capacity of wear resistance against soil. In this paper, the foreleg, tergum and forewing of mole cricket were chosen as soil-engaging components and were observed by stereomicroscope (SM), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The functions of the components were analyzed from the viewpoints of both entomology and bionics. The factors for function realization were found, and the single effect and coupling effect of these factors were investigated. Results show that the wear resistance characteristic of mole cricket is realized by biology coupling. The research of biology coupling provides a foundation to the technology of bionic coupling.

The micromorphologies of surfaces of several typical plant leaves were investigated by scanning electron microscopy(SEM). Different non-smooth surface characteristics were described and classified. The hydrophobicity and anti-adhesion of non-smooth leaf surfaces were quantitatively measured. Results show that the morphology of epidermal cells and the morphology and distribution density of epicuticular wax directly affect the hydrophobicity and anti-adhesion. The surface with uniformly distributed convex units shows the best anti-adhesion, and the surface with regularly arranged trellis units displays better anti-adhesion. In contrast, the surface with randomly distributed hair units performs relatively bad anti-adhesion. The hydrophobic models of papilla-ciliary and fold-setal non-smooth surfaces were set up to determine the impacts of geometric parameters on the hydrophobicity. This study may provide an insight into surface machine molding and apparent morphology design for biomimetics engineering.

The improvement of SNR (Signal-to-Noise Ratio) of abnormal engine sounds is of great help in improving the accuracy of engine fault diagnosis. By imitating the way that human technicians use to distinguish abnormal engine sounds from engine acoustics, a humanoid abnormal sound extracting method is proposed. By implementing adaptive Volterra filter in the canonical Adaptive Noise Cancellation (ANC) system, the proposed method is capable of tracing the engine baseline sound which exhibits an intrinsic nonlinear dynamics. Besides, by introducing a template noise tailored from the records of engine baseline sound and taking it as virtual input of the adaptive Volterra filter, the priori knowledge of engine baseline sound, such as inherent correlation, periodicity or phase information, and stochastic factors, is taken into consideration. The hybrid simulations prove that the proposed method is functional. Since the method proposed is essentially a single-sensor based ANC, hopefully, it may become an effective way to extricate the dilemma that canonical dual-sensor based ANC encounters when it is used in extracting fault-featured signals from observed signals.

The fore leg of mole cricket (Orthoptera: Gryllotalpidae) has developed into claw for digging and excavating. As the result of having a well-suited body and appendages for living underground, mole cricket still needs to manoeuvre on land in some cases with some kinds of gait. In this paper, the three-dimensional kinematics information of mole cricket in terrestrial walking was recorded by using a high speed 3D video recording system. The mode and the gait of the terrestrial walking mole cricket were investigated by analyzing the kinematics parameters, and the kinematics coupling disciplines of each limb and body were discussed. The results show that the locomotion gait of mole cricket in terrestrial walking belongs to a distinctive alternating tripod gait. We also found that the fore legs of a mole cricket are not as effective as that of common hexapod insects, its middle legs and body joints act more effective in walking and turning which compensate the function of fore legs. The terrestrial locomotion of mole cricket is the result of biological coupling of three pairs of legs, the distinctive alternating tripod gait and the trunk locomotion.

Extenics is a newly developed interdisciplinary subject combining mathematics, philosophy and engineering. It provides useful formalized qualitative tools and quantitative tools for solving contradictory problems. In this paper, extension theory is introduced briefly and the primary applications of this theory and methods in bionic engineering research are discussed. The extension model of biological coupling functional system is established. In order to identify the primary and secondary sequencing of coupling elements, the Extension Analytic Hierarchy Process (EAHP) was adopted to analyze the contribution of each coupling element to the coupling functional system. Thus, the influence weight factor of each coupling element can be determined, so as to provide a new approach for solving primary and secondary sequencing problem of coupling elements in a quantitative way, and facilitate the subsequent bionic coupling study.

In order to improve the particle erosion resistance of engineering surfaces, this paper proposed a bionic sample which is inspired from the skin structure of desert lizard, Laudakin stoliczkana. The bionic sample consists of a hard shell (aluminum) and a soft core (silicone rubber) which form a two-layer composite structure. The sand blast tests indicated that the bionic sample has better particle erosion resistance. In steady erosion period, the weight loss per unit time of the bionic sample is about 10% smaller than the contrast sample. The anti-erosion mechanism of the bionic sample was studied by single particle impact test. The results show that, after the impact, the kinetic energy of the particle is reduced by 56.5% on the bionic sample which is higher than that on the contrast sample (31.2%). That means the bionic sample can partly convert the kinetic energy of the particle into the deformation energy of the silicone rubber layer, thus the erosion is reduced.

Bionic alumina samples were fabricated on convex dome type aluminum alloy substrate using hard anodizing technique. The convex domes on the bionic sample were fabricated by compression molding under a compressive stress of 92.5 MPa. The water contact angles of the as-anodized bionic samples were measured using a contact angle meter (JC2000A) with the 3 μL water drop at room temperature. The measurement of the wetting property showed that the water contact angle of the unmodified as-anodized bionic alumina samples increases from 90° to 137° with the anodizing time. The increase in water contract angle with anodizing time arises from the gradual formation of hierarchical structure or composite structure. The structure is composed of the micro-scaled alumina columns and pores. The height of columns and the depth of pores depend on the anodizing time. The water contact angle increases significantly from 96° to 152° when the samples were modified with self-assembled monolayer of octadecanethiol (ODT), showing a change in the wettability from hydrophobicity to super-hydrophobicity. This improvement in the wetting property is attributed to the decrease in the surface energy caused by the chemical modification.

Biomimetic surface is an effective ways to promote the performance grade and applied range of materials without altering their substrate. Many improved properties such as resisting fatigue, enduring wear, etc, have been achieved by applying biomimetic morphology or structure to some engineering material surfaces. In this paper, aiming to reveal the relationship between thermal cracking behavior and mechanical properties of engineering materials with biomimetic surface, biomimetic specimens were fabricated using laser technique by imitating the heterogeneous structure on the surface of plant leaves. The effect of thermal fatigue cycling on the tensile properties of H13 die steel specimens with different surfaces (several types of biomimetic surfaces and a smooth surface) was compared and investigated. As a result, due to the coupling effects of the morphological features on the surface and the microstructure characteristics within unit zone, these specimens with biomimetic surface exhibit remarkably enhanced Ultimate Tensile Strength (UTS) and 0.2% Yield Strength (YS) compared with reference specimens while corresponding ductility remains largely unaffected even heightened, whether the thermal fatigue loads or not. The relative mechanisms leading to these improvements have been discussed.

As one of the most important daily motor activities, human locomotion has been investigated intensively in recent decades. The locomotor functions and mechanics of human lower limbs have become relatively well understood. However, so far our understanding of the motions and functional contributions of the human spine during locomotion is still very poor and simultaneous in-vivo limb and spinal column motion data are scarce. The objective of this study is to investigate the delicate in-vivo kinematic coupling between different functional regions of the human spinal column during locomotion as a stepping stone to explore the locomotor function of the human spine complex. A novel infrared reflective marker cluster system was constructed using stereophotogrammetry techniques to record the 3D in-vivo geometric shape of the spinal column and the segmental position and orientation of each functional spinal region simultaneously. Gait measurements of normal walking were conducted. The preliminary results show that the spinal column shape changes periodically in the frontal plane during locomotion. The segmental motions of different spinal functional regions appear to be strongly coupled, indicating some synergistic strategy may be employed by the human spinal column to facilitate locomotion. In contrast to traditional medical imaging-based methods, the proposed technique can be used to investigate the dynamic characteristics of the spinal column, hence providing more insight into the functional biomechanics of the human spine.

As one of the most important daily motor activities, human locomotion has been investigated intensively in recent decades. The locomotor functions and mechanics of human lower limbs have become relatively well understood. However, so far our understanding of the motions and functional contributions of the human spine during locomotion is still very poor and simultaneous in-vivo limb and spinal column motion data are scarce. The objective of this study is to investigate the delicate in-vivo kinematic coupling between different functional regions of the human spinal column during locomotion as a stepping stone to explore the locomotor function of the human spine complex. A novel infrared reflective marker cluster system was constructed using stereophotogrammetry techniques to record the 3D in-vivo geometric shape of the spinal column and the segmental position and orientation of each functional spinal region simultaneously. Gait measurements of normal walking were conducted. The preliminary results show that the spinal column shape changes periodically in the frontal plane during locomotion. The segmental motions of different spinal functional regions appear to be strongly coupled, indicating some synergistic strategy may be employed by the human spinal column to facilitate locomotion. In contrast to traditional medical imaging-based methods, the proposed technique can be used to investigate the dynamic characteristics of the spinal column, hence providing more insight into the functional biomechanics of the human spine.