摘要：Personalized drugs,as well as disease-specific and condition-dependent drug release,have been highly desired in drug delivery systems for effective and safe ***-dimensional(4 D)printing,as a newly emerging technique to develop drug capsules,displays unique advantages that can autonomously control drug release according to the actual physiological ***,core-shell structured hydrogel capsules were developed using a multimaterial extrusion-based 4 D printing method,which consists of a model drug as the core and UV cross-linked poly(N-isopropylacrylamide)(PNIPAM)hydrogel as the *** to the lower critical solution temperature(LCST)-induced shrinking/swelling properties,the prepared PNIPAM hydrogel capsules showed temperature-responsive drug release along with the topography changes in the cross-linked PNIPAM *** in vitro drug release test confirmed that the PNIPAM hydrogel capsules can autonomously control their drug release behaviors according to changes in ambient ***,the increased shell thickness of these capsules causes an obvious reduction in drug release rate,distinctly indicating that the drug release behavior can be well adjusted by setting the shell thickness of the *** proposed 4 D printing strategy pioneers the paradigm of smart drug release by showing great potential in the smart controlled release of drugs and macromolecular active agents.

摘要：The human skin has the ability to sense tactile touch and a great range of ***,in prosthetic or robotic systems,it is necessary to prepare pressure sensors with high sensitivity in a wide measurement range to provide human-like tactile ***,we developed a flexible piezoresistive pressure sensor that is highly sensitive in a broad pressure range by using lotus leaf micropatterned polydimethylsiloxane and multilayer *** superposing four layers of micropatterned constructive substrates,the multilayer piezoresistive pressure sensor achieves a broad pressure range of 312 kPa,a high sensitivity of 2.525 kPa^(−1),a low limit of detection(LOD)of<12 Pa,and a fast response time of 45 *** with the traditional flexible pressure sensor,the pressure range of this sensor can be increased by at least an order of *** flexible piezoresistive pressure sensor also shows high robustness:after testing for at least 1000 cycles,it shows no sign of *** importantly,these sensors can be potentially applied in various human motion detection scenarios,including tiny pulse monitoring,throat vibration detection,and large under-feet pressure *** proposed fabrication strategy may guide the design of other kinds of multifunctional sensors to improve the detection performance.

摘要：Mammals such as humans develop skeletal muscles composed of muscle fibers and connective tissue,which have mechanical properties that enable power output with three-dimensional motion when *** muscle-like actuators developed to date,such as the McKibben artificial muscle,often focus sole contractile elements and have rarely addressed the contribution of flexible connective tissue that forms an integral part of the structure and morphology of biological ***,we present a class of pneumatic muscle-like actuators,termed highly mimetic skeletal muscle(HimiSK)actuator,that consist of parallelly arranged contractile units in a flexible matrix inspired by ultrasonic measurements on skeletal *** contractile units act as a muscle fiber to produce active shortening force,and the flexible matrix functions as connective tissue to generate passive *** application of positive pressure to the contractile units can produce a linear contraction and *** this actuator,we assign different flexible materials as contractile units and a flexible matrix,thus forming five mold *** actuators feature three-dimensional motion on activation and present both intrinsic force-velocity and force-length characteristics that closely resebmle those of a biological *** output and tetanic force produced by harder contractile units improve the maximum output force by up to about 41.3%and the tetanic force by up to about 168%.Moreover,high displacement and velocity can be generated by a softer flexible matrix,with the improvement of maximum displacement up to about 33.3%and velocity up to about 73%.The results demonstrate that contractile units play a crucial role in force generation,while the flexible matrix has a significant impact on force transmission and deformation;the final force,velocity,displacement,and three-dimensional motion results from the interplay of contractile units,fluid and flexible *** approach introduces a m

摘要：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 ***,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 *** stronger the interactions,the greater the innovation success would *** 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.

摘要：It is very important to analyze and study the motion process of droplets impacting superhydrophobic surface, which is of great significanee to understand the mechanism of superhydrophobic surface and guide the design and manufacture of superhydrophobic surface. Taking by three-dimensional volume of fluid (VOF) simulation coupling coupled level set (CLS) algorithm, on the one hand, we simulate the morphological changes in the process of droplet impingement, as well as the internal velocity and the pressure distribution;on the other hand,we focus on the effects of droplet impact velocity, surface wettability, surface tension on the dynamics of the droplets. The CLSVOF model inherits the advantages of the VOF model for accurately constructing the phase interface and inherits the advantage that the level set can accurately calculate the surface tension, which improves the accuracy of the calculation of the droplet impact on the superhydrophobic surface. The computed results distinctly demonstrated there were four stages: falling, spreading, shrinking and rebounding. The time history of each stage agreed well with the pictures captured by high-speed camera, which indicated the computational fluid dynamics scheme was effective. Moreover, the motion mechanism of the droplets impacting on the solid surface is elaborated, which was helpful to control the solid-liquid interface to achieve a variety of solid interface characteristics.

摘要：Shape memory polymers(SMPs)are a promising class of materials for biomedical applications due to their favorable mechanical properties,fast response,and good ***,it is difficult to achieve controllable sequential shape change for most SMPs due to their high deformation temperature and the simplex deformation ***,shape memory composites based on polylactic acid(PLA)matrix and semi-crystalline linear polymer polycaprolactone(PCL)are fabricated using 4D printing *** with pure PLA,with the rise of PCL content,the 4D-printed PLA/PCL composites show decreased glass transition temperature(Tg)from 67.2 to 55.2°*** the precise control of the deformation condition,controllable sequential deformation with an outstanding shape memory effect can be achieved for the PLA/PCL shape memory *** response time of shape recovery is less than 1.2 s,and the shape fixation/recov-ery rates are above 92%.In order to simulate sequential petal opening and sequential drug releasing effects,a double-layer bionic flower and a drug release device,respectively,are presented by assembling PLA/PCL samples with different PLA/PCL *** results indicate the potential applications of 4D-printed PLA/PCL composites in the field of bio-inspired robotics and biomedical devices.

摘要：The reduction of water resources and soil fertility in Northeast China will have a requirement on higher working efficiency of agricultural soil-engaging *** adhesion and resistance are main problems for soil-engaging tillage ***,the soil-burrowing or soil-digging animals give inspirations to resolve those *** fair,claw,toe,textured surface and scales have functions of anti-adhesion or resistance *** results provide a way to realize the sustainable development of modern agriculture by developing novel biomimetic agricultural machinery systems with independent intellectual property rights to meet conservation tillage requirements in the Northern China *** structures of some soil-burrowing or soil-digging animals,such as beetle,mole cricket,earthworm,mole,vole,pangolin,and snake,as well as their mechanisms of anti-adhesion or reducing resistance were reviewed in this *** applications in Northeast China were also presented in the paper,including moldboard,subsoiler components,furrow opener,roller,and biomimetic rototilling-stubble-breaking *** addition,the existed problems in agricultural engineering and the future development trends were discussed.

摘要：With the growing demand and working complexity of corn precision planter,it becomes more important to monitor the working performance through intelligent systems.A new fault monitoring system for corn precision planters was designed and *** system consisted of the information acquisition module,controller module,alarm module,input module and display module.A capacitive sensor was utilized to monitor the seed flow without changing the track of a precision *** system can monitor the whole sowing process of a seed-metering device in *** sowing status,fault type and fault location can be displayed on liquid crystal display(LCD).Warning light on the LCD reminds the operator of abnormal *** tests and field tests showed that the minimum monitoring accuracies of missing sowing and total sowing number were 92.11%and 94.28%,respectively,and the seed level sensor and the opener sensor worked *** system can accurately prompt the seed-metering mechanism in real-time.

摘要：The blocking between two snapping rollers will seriously constrict the harvesting efficiency for corn harvester.A variable screw pitch rib snapping roller was developed to solve this *** comparative experiment between fixed screw pitch rib snapping rollers and variable screw pitch rib snapping rollers illustrated that variable screw pitch ribs can avoid corn-stalk blocking effectively,and it can improve working efficiency by 56.7%.Conservation tillage with standing corn residue was testified that it had a strong control of soil wind *** order to implement this mode of conservation tillage at a production scale,a cutter was developed in this ***,two experiments were conducted,one was to test the cutting ratio(defined as the totally cut off stalk population divided by total stalk population),and the other one was to test standing-residue *** experiment results showed that the mean cutting ratio increased significantly(p<0.05)along with increasing height of cutter-head above the ground(cutting height);the cutting ratio’s mean value increased significantly(p<0.05)along with the decreasing angle between the cutter-head and the ground(cutting angle).The average standing-residue height increased along with the increase of cutting height from 300 mm to 500 *** average standing-residue height increased significantly(p<0.05)along with the decrease of cutting angle from 15°to 0°.Therefore,the newly designed snapping roller can improve the harvesting efficiency and prolong the working life of the cutting table;and the cutter can promote the popularization of the conservation tillage with standing corn residue in Northeast China.

摘要：使用扫描电子显微镜（SEM）、接触角测量仪和红外光谱仪（FT-IR），观测了27种蝴蝶翅表面的微观结构、复合浸润性和化学成分．利用Cassie方程建立了蝴蝶翅表面微／纳结构疏水模型，从生物耦合角度探讨了疏水机理．结果表明，蝴蝶翅表面由天然疏水材料组成，具有复杂的多级微／纳结构，包括一级结构（微米级鳞片）、二级结构（纳米级纵肋和横桥）和三级结构（纳米级突起）．翅表面具有高疏水性（接触角138°～157°）和低黏附性（滚动角1°-3°）．翅表面微观形貌和自清洁性具有显著的各向异性．这种特殊的复合浸润性是材料耦元与结构耦元耦合怍用的结果．微米级鳞片的宽度越小、间距越大，纳米级纵助的高度越小、宽度越小、问距越大，翅表面疏水性越强．研究结果有助于进一步流调结果揭示生物表面的疏水机理，为智能界面材料的仿生设计和制备提供启示．