Abstract: In order to improve ability of walking and crossing the barriers , increase the carrying capacity, and enhance its popularity and adaptability, a novel lower limb bionic leg is presented based on 3-UPS parallel mechanism, which has the characteristics of movement flexible and strong adaptability. It is very important analysis to statics of lower limb bionic leg. Firstly, statics equation of the lower limb bionic leg of driving force and output force is established based on virtual work principle. Secondly, static performance evaluation index is defined and the evaluation index distribution map is drawn. The relationship between the structure parameters and the static performance evaluation indexes is analyzed, obtained the influence of structure parameters on the static performance evaluation index, and a set of reasonable structural parameters is selected. The circum-radius of moving platform is 50mm, the circum-radius of the static platform is 150mm, the moving platform angle and static platform angle are equal to 60°, the lower limb bionic leg has the best load carrying capacity. Thirdly, the lower limb bionic leg is designed based on statics analysis and structure parameters optimization. Analysis results show that the lower limb bionic leg has good static transmission performance at the initial position, and the static transmission performance decreases with increasing turning workspace. The static transmission performance decreases with z axle displacement increasing. The analysis results laid a foundation for further analysis and research of the lower limb bionic leg.
Abstract: In this manuscript, a bionic linear actuator was developed base on the ionic actuator: ionicpolymer metal composites, and the mainly fabrication method was presented in the currentinvestigation. Subsequently, a bionic robot was developed using 3D printing technique to fabricatethe skeleton structure and the presented Bi-IPMC(assembled by two segmented IPMC strip) linearactuator as the driving power. After a mathematical model of bionic robot, a experimented bionicrobot was manufactured to investigate. The results founded that our bionic robot behaved a maximumbounce height arrived at 22mm under applied 5V direct current, and the bounce height can keep onthe values of 18mm over the applied voltage of 4V.
Abstract: With the increasing popularity of barefoot running, the difference of foot morphology between habitually unshod runners and shod runners is becoming one concern leading to running injuries. The purpose of this study was to analyze the foot skeletal morphological characteristics between habitually unshod runner and shod runner through inverse modelling. A total of eight subjects, including four habitually unshod runners and four habitually shod runners participated in the Computed Tomography (CT) foot scanning test and Mimics was utilized to rebuild foot model and the Inter-Metatarsal Angle (IMA), Metatarsal-Phalangeal Angle (MPA), and Inter-Phalangeal Distance (IPD) were measured to illustrate the morphology difference. The results showed that the Inter-Phalangeal Distance and Inter-Metatarsal Angle of unshod runners were obviously bigger than those of habitually shod feet. And the difference of Inter-Metatarsal Angle between unshod runner and shod runner was also distinct. Not only can this finding be proven of foot morphology variations, but also it can confirm the development of nature foot from unshod running to shod running.
Abstract: One of the most widely used techniques in present-day in order to save teeth is endodontic treatment (ET). Nowadays, a post or a dowel is widely used in the tooth treatment process. The aims of the current investigation are to: (1) evaluate the stress distribution surrounding the endodontic prefabricated parallel post (EPPP), gutta-percha, and dentin with six types of post materials, and (2) determine the optimum material of an EPPP. Six post materials: (1) carbon fibre post (CFP), (2) gold (G), (3) gold alloy (GA), (4) titanium (T), (5) titanium alloy (TA), and (6) stainless steel (SS) were selected in the present work. In order to evaluate the stress distribution surrounding the EPPP, gutta-percha, and dentin with different post materials, the finite element analysis (FEA) is adopted. After that, the sub-problem approximation method was used in order to investigate the optimum material of an EPPP. The results obtained indicate that the optimum elastic characteristics for the EPPP, elastic modulus (E), and Poisson’s ratio (υ) equal to 185 GPa and 0.245, respectively.
Abstract: This study is conducted to investigate the effects of losing fluid during extension of rabbit ACL (Anterior Cruciate Ligament) on its nonlinear behavior. The incompressible Neo-Hookean model is employed for modeling the mechanical response of ACL under the uniaxial loading. The material properties of the ligament are characterized by measuring the deformation of a continuum element regarding to two assumptions, the exact and near incompressible cases. In the near incompressible assumption, it is assumed that some fluids exit during ligament extension which influence the nonlinear structural response of the ACL. Finally, considering the nonlinearity of the ligament due to the material behavior and geometrical effect, the ligament behavior is modeled using the nonlinear FEM solution. This study provides a new insight based on the model incompressibility for the ACL of the rabbit knee. These findings help researchers to predict the patterns of injuries that occur in the ligament for different amount of losing fluid by developing the computational model to assess the nonlinear response
Abstract: The objectives of this study are to observe the deformation of mitral leaflet in systole condition and compare the rigidity of heart valve leaflet during systole and diastole conditions. Two-dimensional model of the mitral valve leaflet with ventricle were created using fluid structure interaction model in computational simulations. The result shows rigidity of heart valve leaflet always opposite to degeneration and the simulated displacement models corresponded to normal deformation in physical heart valve in systole condition. Modeling simulation techniques are very useful in the study of degenerative heart valve and the findings would allow us to optimize feature and geometries to reduced deformation of heart valve failure.
Abstract: Engineering a cell-friendly material in a form of lab-on-chip is the main goal of this study. The chip was made of polydimethyl siloxane (PDMS) with a surface modification to realize a groovy structure on its surface. This groovy surface was naturally and randomly designed via biomachining process. This measure was aimed to improve the cell attachment on the PDMS surface that always known as hydrophobic surface. The biomachined surface of mold and also products were characterized as surface roughness and wettability. The result shows that the biomachining process were able to be characterized in three classes of roughness on the surface of PDMS.
Abstract: This paper summarizes research on infrared absorption spectrum of gum Arabica, a Bio-material. The frequency shift due to deuterium exchange in gum Arabica molecule and rotational spectrum of bio-molecules are estimated from the measured data of FTIR spectra. The obtained shift of the characteristics frequency caused due to deuterium exchange in the –OH bond of gum Arabica. Normally two major region in the IR spectrum of a molecule are the functional group region ( 7000 cm-1 to 1500 cm-1) it includes the X-H stretching region and finger print region ( 1500 cm-1 to 350 cm-1). The mentioned region is very important in bio-molecular dynamics and it may provide much relevant information about the internal motion of the molecule and is related bio-molecular function in living systems. The change in molecular structure, of the constituent bio-molecules of Gum Arabica, due deuterium exchange is directly determined from analysis of FTIR spectrum in functional group region. The rotational constants as well as the ground state rotational energy levels are estimated from analysis of FTIR spectrum of the experimental specimens. A map of quantum energy levels of the bio-molecule has been extracted from this present FTIR analysis.
Abstract: The formation of layered ripples covered pyramid structure is reported on 316L stainless steel surface with femtosecond laser pulses in this paper. These unique structures form though a combination of preferential ablation of flat regions around the pyramids and extension of layered ripples created during the ablation process. The cause of the formation about these structure is investigated using multi-means and the results show that these structures are derived from an inhomogeneous distribution of laser fluence, which is caused through a combination of the redeposition of nanoparticles and the local oxidation as well as the geometric factors.
Abstract: Most etiology of bad breath is often concerned with gram-negative anaerobic bacteri, and pharmacotherpy using pharmaceutical drugs should be effective but limited, because bacteria at deep periodontal pocket may be sterilized but cannot be washed out and the malodorous compounds remain. The absorbents for the malodorous compound such as volatile sulfur compounds (VSC), hydrogen sulfide (H2S), are expected to prevent the teeth from decaying and peiodontics disease. The VSC adsorption capabilities of layered double hydroxides, of which composition is A1-xBx(OH)2Cx/n·mH2O, where A and B are Mg and Fe ions, and C are carbonate (CO32- : MgFe HTCO3) and chlorine (Cl - : MgFe HTCl) ions in aqueous medium was studied by GC/FPD. The concentration of H2S rapidly decrease to less than 15% for first 1 hours of soaking in H2S water and fell to 0% in 4-5 h when the MgFe HTCO3 and MgFe HTCl were used. The iron ion was not detected in the H2S water after soaking for 18 hours.The MgFe HTCO3 and MgFe HTCl are expected to be likely adsorbent for the fast removal of VSC from the mouth.