On elastocapillarity:A review

Elastocapillary phenomena involving elastic deformation of solid structures coupled with capillary effects of liquid droplets/films can be observed in a diversity of fields, e.g., biology and microelectromechanical systems （MEMS）. Understanding the physical mechanisms underlying these phenomena is of great interest for the design of new materials and devices by utilizing the effects of surface tension at micro and nano scales. In this paper, some recent developments in the investigations on elastocapillary phenomena are briefly reviewed. Especially, we consider the deformation, adhesion, self-assembly, buckling and wrinkling of ma- terials and devices induced by surface tensions or capillary forces. The main attention is paid to the experimental results of these phenomena and the theoretical analysis meth- ods based on continuum mechanics. Additionally, the applications of these studies in the fields of MEMS, micro/nanometrology, and biomimetic design of advanced materials and devices are discussed.

A unified analysis of a micro-beam,droplet and CNT ring adhered on a substrate:Calculation of variation with movable boundaries

In this study, we developed a general method to analytically tackle a kind of movable boundary problem from the viewpoint of energy variation. Having grouped the adhesion of a micro-beam, droplet and carbon nanotube （CNT） ring on a substrate into one framework, we used the developed line of reasoning to investigate the adhesion behaviors of these systems. Based upon the derived governing equations and transversality conditions, explicit solutions involving the critical parameters and morphologies for the three systems are successfully obtained, and then the parameter analogies and common characteristics of them are thor- oughly investigated. The presented method has been verified via the concept of energy release rate in fracture mechanics. Our analyses provide a new approach for exploring the mechanism of different systems with similarities as well as for understanding the unity of nature. The analysis results may be beneficial for the design of nano-structured materi- als, and hold potential for enhancing their mechanical, chemical, optical and electronic properties.

Why a mosquito leg possesses superior load-bearing capacity on water:Experimentals

Mosquitoes possess the striking ability to walk on water because each of their legs has a huge water supporting force（WSF） that is 23 times their body weight.Aiming at a full understanding of the origins of this extremely large force,in this study,we concentrate on two aspects of it：the intrinsic properties of the leg surface and the active control of the initial stepping angle of the whole leg.Using a measurement system that we developed ourselves,the WSFs for the original leg samples are compared with those whose surface wax and microstructures have been removed and with those of a different stiffness.The results show that leg f exibility plays a dominant role over surface wax and microstructures on the leg surface in creating the supporting force.Moreover,we discuss the dependence relationship between the maximum WSF and the initial stepping angle,which indicates that the mosquito can regulate this angle to increase or decrease the WSF during landing or takeoff.These finding are helpful for uncovering the locomotion mechanism of aquatic insects and for providing inspiration for the design of microfluids miniature boats,biomimetic robots,and microsensors.

Are incidence and severity of clubfoot related to the season of birth?

Background:This study was designed to determine whether the occurrence of clubfoot follows a seasonal pattern in neonates from eastern and south-eastern China and to speculate the potential etiology of clubfoot.Methods:We reviewed 239 neonates with clubfeet during a period of 4 years as well as the monthly neonatal population of the Sixth National Population Census.Seasonal variations in terms of month of birth and severity were analyzed.Results:The incidence of clubfoot in neonates from eastern and south-eastern China showed seasonal variations,and the incidence was higher in autumn with a reference to the average birth rate in this corresponding area.No signifi cant difference was found in severity of clubfoot.Conclusion:This seasonal pattern is of signifi cant value to further understanding the etiology and pathogenesis of clubfoot in the corresponding area of China.

Dye-sensitized solar cells based on functionalized truxene structure

Three new metal-free organic dyes （TX1, TX2 and TX3） based on truxene core structure, with triphenylamine as the electron donor, thiophene as the n spacers, and cyanoacetic acid or rhodanine-3- acetic acid as the electron acceptor are designed and synthesized. Their UV-vis absorption spectra, electrochemical and photovoltaic properties were investigated. The cyanoacrylic acid is verified to be a better acceptor unit （meanwhile the anchoring group） compared to the rhodanine-3-acetic acid. And also, two anchoring groups in TX2 could provide stronger adsorption ability on the TiO2 surface. In addition, the EIS results indicate a slower charge recombination processes for TX2. As a result, dye TX2 bearing two cyanoacetic acid outperforms the other two dyes, exhibiting the photo-conversion efficiency of 2.64%, with Jsc = 5.09 mAcm^-2, Voc = 729 mV, FF = 71.1.

Manipulation of a temporal electron-spin splitter via aδ-potential in an embedded magnetic-electric-barrier microstructure

We theoretically explore the manipulation of a temporal electron-spin splitter by aδ-potential in an embedded magnetic-elec tric-barrier micro structure(EMEBM),which is constructed by patterning a ferromagnetic stripe and a Schottky-metal stripe on the top and bottom of an InAs/Al_(x)In_(1-x)As heterostructure,respectively.Spin polarization of the dwell time remains,even though aδ-potential is inserted by atomic-layer doping.Both the magnitude and sign of the spinpolarized dwell time can be manipulated by changing the weight or position of the 6-potential.Thus,a structurally controllable temporal electron-spin splitter can be obtained for spintronics device applications.

Combined fenestrated/chimney thoracic endovascular repair for the treatment of blunt traumatic aortic injury:A case report

Blunt traumatic thoracic aortic injury(BTAI)is an extremely serious medical condition with a high rate of associated mortality.Recent advances in techniques such as thoracic endovascular repair offer new opportunities to manage the critical BTAI patients in an efficacious yet less invasive manner.A 65 year-old-male suffered from multiple injuries after a fall,including BTAI in the aortic arch,which resulted in dissection of the descending thoracic-abdominal aorta and iliac artery,development of an intimal flap in the left common carotid artery,and dissection of the left subclavian artery.Based on the imaging information of this patient and our clinical experience,the combined treatment of fenestrated thoracic endovascular repair and a chimney technique was immediately planned to fully repair these dissections and moreover prevent further dissection of the branching vessels,additionally to ensure sufficient blood flow in the left subclavian artery and left common carotid artery.The intervention yielded satisfactory early outcomes.Follow-up assessment at six months reported no symptoms or complications associated with the stent-graft.Computed tomography angiography further confirmed adequate stent-graft coverage of the aortic injury.