During the metal cutting process,especially in continuous contact conditions like turning,the challenge of lubricants failing to effectively reach the cutting point remains unresolved.Micro-textured cutting tools offe...During the metal cutting process,especially in continuous contact conditions like turning,the challenge of lubricants failing to effectively reach the cutting point remains unresolved.Micro-textured cutting tools offer a potential solution for tool-chip contact challenges.Inspired by the evolutionary achievements of the biosphere,micro-textures are expected to overcome lubrication limitations in cutting zones.Drawing on the anti-gravity water transport seen at the mouth edge of the Nepenthes plant,an innovative microchannel with Nepenthes-shaped contours was designed on the rake face to enable controlled lubricant transport.However,the dynamics of lubricant delivery on textured surfaces are not fully understood.This study first analyzed the microstructure and water transport mechanism of Nepenthes to reconstruct a micro-textured surface for controlled lubricant transport.A dynamic model was then developed to describe lubricant transport within open microchannels,with mathematical simulations predicting transport speed and flow distance.To validate this model,diffusion experiments of alumina soybean oil nanolubricant on polycrystalline diamond(PCD)cutting tool surfaces were conducted,showing an average prediction deviation of 5.01%.Compared with the classical Lucas-Washburn model,the new model improved prediction accuracy by 4.72%.Additionally,comparisons were made to examine droplet spreading and non-uniform diffusion on textured surfaces,revealing that the T2 surface exhibited the strongest unidirectional diffusion characteristics.The contact angle ratio,droplet unidirectional spreading ratio,and droplet spreading aspect ratio were 0.48,1.75,and 3.99,respectively.Finally,the anti-wear,friction-reducing,and efficiency-enhancing mechanisms of micro-textured surfaces in minimum quantity lubrication turning were analyzed.This approach may support continuous cutting of difficult-tomachine materials.展开更多
Carnivorous plants of Nepenthes species have evolved particular organs named pitchers at the tips of their conspicuous leaves, allowing slippery trapping and effective digesting prey to acquire sufficient growing nutr...Carnivorous plants of Nepenthes species have evolved particular organs named pitchers at the tips of their conspicuous leaves, allowing slippery trapping and effective digesting prey to acquire sufficient growing nutrients. Nepenthes pitchers are generally distinguished by several morphological regions exhibiting distinct functions in prey capturing, and combined effect of the several zones results in great trapping efficiency. Depending on specific micro-structures, slippery zone performs an important role in efficiently preying arthropods, and this prey ability inspires an idea for biomimetic development of slippery trapping plate used in controlling agricultural pests. In this paper, combined with our latest results, the authors introduced the recent studies of the slippery zone, including surface structures and anti-attachment functions. They also highlighted the biomimetic application of slippery zone in developing slippery trapping plate for controlling agricultural pest.展开更多
Soft tissue sticking to electrosurgical electrodes in minimally invasive surgery can cause tissue trauma,laceration,and bleeding and can easily lead to medical accidents.The multilevel structure on the peristome surfa...Soft tissue sticking to electrosurgical electrodes in minimally invasive surgery can cause tissue trauma,laceration,and bleeding and can easily lead to medical accidents.The multilevel structure on the peristome surface of Nepenthes alata creates a stable liquid film and long-term slippery phenomena,providing excellent antisticking performance.However,transferring the multilevel structure to metallic substrates is a critical challenge.Herein,a facile method using a bionic replication process combined with an electroforming process was reported to successfully prepare a realistic metallic-peristome surface(MPS)from the peristome surface of Nepenthes alata to a copper-based substrate.The long-term lubrication theory of MPS was analyzed,which demonstrated the high wettability and robustness of the surface.The unidirectional transport behavior and long-term lubrication performance of dimethyl silicone oil on the MPS under the action of a thermal field gradient were analyzed.The results show that the as-prepared metallic-peristome surface has liquid transport capability in the opposite direction of the thermal field gradient.In addition,the introduction of microstructures on the surface of the MPS electrode can promote the occurrence of spark effects and improve the cutting effect.An electrocution test of isolated pig liver tissue was conducted to test the tissue antisticking properties,thermal damage,and antibacterial effects of self-lubricating slippery surface bionic electrosurgery.MPS exhibits excellent antistick properties,low thermal damage,and significant antibacterial properties,laying the foundation for its application in other fields.展开更多
Unidirectional liquid transport without any need of external energy has drawn worldwide attention for its potential applications in various fields such as microfluidics,biomedicine and mechanical engineering.In nature...Unidirectional liquid transport without any need of external energy has drawn worldwide attention for its potential applications in various fields such as microfluidics,biomedicine and mechanical engineering.In nature,numerous creatures have evolved such extraordinary unidirectional liquid transport ability such as spider sik,Sarracenia's trichomes,and Nepenthes alata's peristome,etc.This review summarizes the current progresses of natural unidirectional liquid transport on 1-Dimensional(1D)linear structure and 2-Dimensional(2D)surface stucture.The driving force of unidirectional liquid transport which is determined by unique structure exist distinct differences in physics.The fundamental understanding of 1D and 2D unidirectionaliquid transport especially about hierarchical structural characteristics and their transport mechanism were concentrated,and various bioinspired fabrication methods are also introduced.The applications of bioinspired directional liquid transport are demonstrated especially in fields of microfluidies,biomedical devices and anti-icing surfaces.With newly developed smart materials,various liquid transport regulation strategies are also summarized for the control of transport speed,direction guiding,etc.Finally,we provide new insights and future perspectives of the directional transport materials.展开更多
A dichotomous key and descriptions of the species of pitcher plants recorded from bris forest at Jambu Bongkok is given.Three species of pitcher plants were recognized from the study area.They are Nepenthes rafflesian...A dichotomous key and descriptions of the species of pitcher plants recorded from bris forest at Jambu Bongkok is given.Three species of pitcher plants were recognized from the study area.They are Nepenthes rafflesiana,Nepenthes gracilis and Nepenthes mirabilis.These species can easily be identified by their morphological differences.Nepenthes gracilis differed from the other two species in having triangular stem,sessile leaves,winged leaf base,under lid surface of the pitcher sparsely covered with honey glands,inner pitcher cavity wall covered exposed digestive glands and very narrow peristome with the thickness of≤1 cm.On the other hand,Nepenthes rafflesiana and Nepenthes mirabilis have cylindrical stem,stalked leaves,semi-amplexicaul leaf base,under lid surface densely covered with honey glands,inner pitcher cavity wall covered with overarched digestive glands and broad peristome with a thickness of≥1 cm.Nepenthes rafflesiana can be differentiated from Nepenthes mirabilis by its infundibulate upper pitcher,ellipsoidal lower pitcher,inner pitcher wall cavity wholly covered with digestive glands whereas Nepenthes mirabilis have tublose-ventricose upper and lower pitchers,inner pitcher cavity wall of both pitchers partly covered with digestive glands.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.52375447,52305477 and 52105457)Shandong Provincial Natural Science Foundation(Grant Nos.ZR2023QE057,ZR2024QE100 and ZR2024ME255)+2 种基金Qingdao Municipal Science and Technology Planning Park Cultivation Plan(Grant No.23-1-5-yqpy-17-qy)the Science and Technology SMEs Innovation Capacity Improvement Project of Shandong Province(Grant No.2022TSGC1115)the Special Fund of Taishan Scholars Project。
文摘During the metal cutting process,especially in continuous contact conditions like turning,the challenge of lubricants failing to effectively reach the cutting point remains unresolved.Micro-textured cutting tools offer a potential solution for tool-chip contact challenges.Inspired by the evolutionary achievements of the biosphere,micro-textures are expected to overcome lubrication limitations in cutting zones.Drawing on the anti-gravity water transport seen at the mouth edge of the Nepenthes plant,an innovative microchannel with Nepenthes-shaped contours was designed on the rake face to enable controlled lubricant transport.However,the dynamics of lubricant delivery on textured surfaces are not fully understood.This study first analyzed the microstructure and water transport mechanism of Nepenthes to reconstruct a micro-textured surface for controlled lubricant transport.A dynamic model was then developed to describe lubricant transport within open microchannels,with mathematical simulations predicting transport speed and flow distance.To validate this model,diffusion experiments of alumina soybean oil nanolubricant on polycrystalline diamond(PCD)cutting tool surfaces were conducted,showing an average prediction deviation of 5.01%.Compared with the classical Lucas-Washburn model,the new model improved prediction accuracy by 4.72%.Additionally,comparisons were made to examine droplet spreading and non-uniform diffusion on textured surfaces,revealing that the T2 surface exhibited the strongest unidirectional diffusion characteristics.The contact angle ratio,droplet unidirectional spreading ratio,and droplet spreading aspect ratio were 0.48,1.75,and 3.99,respectively.Finally,the anti-wear,friction-reducing,and efficiency-enhancing mechanisms of micro-textured surfaces in minimum quantity lubrication turning were analyzed.This approach may support continuous cutting of difficult-tomachine materials.
文摘Carnivorous plants of Nepenthes species have evolved particular organs named pitchers at the tips of their conspicuous leaves, allowing slippery trapping and effective digesting prey to acquire sufficient growing nutrients. Nepenthes pitchers are generally distinguished by several morphological regions exhibiting distinct functions in prey capturing, and combined effect of the several zones results in great trapping efficiency. Depending on specific micro-structures, slippery zone performs an important role in efficiently preying arthropods, and this prey ability inspires an idea for biomimetic development of slippery trapping plate used in controlling agricultural pests. In this paper, combined with our latest results, the authors introduced the recent studies of the slippery zone, including surface structures and anti-attachment functions. They also highlighted the biomimetic application of slippery zone in developing slippery trapping plate for controlling agricultural pest.
基金funded by the National Natural Science Foundation of China(Nos.52205306 and 51935001)the Hebei Natural Science Foundation(No.E2022208039)+1 种基金the Science and Technology Project of the Hebei Education Department(No.BJK2023028)the Central Guidance on Local Science and Technology Development Fund of Hebei Province(No.236Z1802G).
文摘Soft tissue sticking to electrosurgical electrodes in minimally invasive surgery can cause tissue trauma,laceration,and bleeding and can easily lead to medical accidents.The multilevel structure on the peristome surface of Nepenthes alata creates a stable liquid film and long-term slippery phenomena,providing excellent antisticking performance.However,transferring the multilevel structure to metallic substrates is a critical challenge.Herein,a facile method using a bionic replication process combined with an electroforming process was reported to successfully prepare a realistic metallic-peristome surface(MPS)from the peristome surface of Nepenthes alata to a copper-based substrate.The long-term lubrication theory of MPS was analyzed,which demonstrated the high wettability and robustness of the surface.The unidirectional transport behavior and long-term lubrication performance of dimethyl silicone oil on the MPS under the action of a thermal field gradient were analyzed.The results show that the as-prepared metallic-peristome surface has liquid transport capability in the opposite direction of the thermal field gradient.In addition,the introduction of microstructures on the surface of the MPS electrode can promote the occurrence of spark effects and improve the cutting effect.An electrocution test of isolated pig liver tissue was conducted to test the tissue antisticking properties,thermal damage,and antibacterial effects of self-lubricating slippery surface bionic electrosurgery.MPS exhibits excellent antistick properties,low thermal damage,and significant antibacterial properties,laying the foundation for its application in other fields.
基金the National Key R&D Program of China(No.2019YFB1309702)the National Natural Science Foundation of China(Nos.51935001,51725501 and 51905022).
文摘Unidirectional liquid transport without any need of external energy has drawn worldwide attention for its potential applications in various fields such as microfluidics,biomedicine and mechanical engineering.In nature,numerous creatures have evolved such extraordinary unidirectional liquid transport ability such as spider sik,Sarracenia's trichomes,and Nepenthes alata's peristome,etc.This review summarizes the current progresses of natural unidirectional liquid transport on 1-Dimensional(1D)linear structure and 2-Dimensional(2D)surface stucture.The driving force of unidirectional liquid transport which is determined by unique structure exist distinct differences in physics.The fundamental understanding of 1D and 2D unidirectionaliquid transport especially about hierarchical structural characteristics and their transport mechanism were concentrated,and various bioinspired fabrication methods are also introduced.The applications of bioinspired directional liquid transport are demonstrated especially in fields of microfluidies,biomedical devices and anti-icing surfaces.With newly developed smart materials,various liquid transport regulation strategies are also summarized for the control of transport speed,direction guiding,etc.Finally,we provide new insights and future perspectives of the directional transport materials.
基金This project is funded by Malaysian Government Research and Development Fund(R and D)09-02-02-0090-EA233in part by Universiti Kebangsaan Malaysia research grant ST一017-2003,ST一611-2002.
文摘A dichotomous key and descriptions of the species of pitcher plants recorded from bris forest at Jambu Bongkok is given.Three species of pitcher plants were recognized from the study area.They are Nepenthes rafflesiana,Nepenthes gracilis and Nepenthes mirabilis.These species can easily be identified by their morphological differences.Nepenthes gracilis differed from the other two species in having triangular stem,sessile leaves,winged leaf base,under lid surface of the pitcher sparsely covered with honey glands,inner pitcher cavity wall covered exposed digestive glands and very narrow peristome with the thickness of≤1 cm.On the other hand,Nepenthes rafflesiana and Nepenthes mirabilis have cylindrical stem,stalked leaves,semi-amplexicaul leaf base,under lid surface densely covered with honey glands,inner pitcher cavity wall covered with overarched digestive glands and broad peristome with a thickness of≥1 cm.Nepenthes rafflesiana can be differentiated from Nepenthes mirabilis by its infundibulate upper pitcher,ellipsoidal lower pitcher,inner pitcher wall cavity wholly covered with digestive glands whereas Nepenthes mirabilis have tublose-ventricose upper and lower pitchers,inner pitcher cavity wall of both pitchers partly covered with digestive glands.
