利用环境扫描电子显微镜(ESEM)和原子力显微镜(AFM)表征红瓶猪笼草蜡质滑移区表面微观形貌，并提取粗糙度的相关参数。利用AFM分别在低载荷和高载荷下对蜡质区表面同一区域进行扫描，在不同条件下的扫描形貌一致，且扫描后的探针针尖上未发现附着污染物。利用胶体探针技术在无针尖的探针悬臂上粘附15 μm SiO2小球，模拟单根刚毛与猪笼草蜡质区表面的接触，并测试蜡质区表面的粘附力和摩擦力，并与不同粗糙度的抛光纸表面做对照。考虑到表面物理化学性质对其粘附特性的重要影响，利用接触角测量仪测量蜡质区表面和同粗糙度范围抛光纸表面对水和二碘甲烷的表观接触角并利用二滴法计算其表面能。研究结果表明：蜡质滑移区表面单个蜡质晶体具有力学稳定性，不会因脱落而污染昆虫的粘附器官，污染学说不成立；表面微粗糙度能有效地减小界面间的接触面积，降低了蜡质滑移区表面的粘附力和摩擦力；蜡质滑移区超疏水特性和低表面能是降低表面粘附力和摩擦力的另一个重要因素，两者共同作用形成了猪笼草蜡质滑移区的反粘附特性。
毕可东
,
宋小闯
,
王玉娟
,
杨决宽
,
陈云飞
. 猪笼草蜡质滑移区表面反粘附特性的研究[J]. 机械工程学报, 2015
, 51(23)
: 103
-109
.
DOI: 10.3901/JME.2015.23.103
The micro-topography and geometrical parameters of the surface of nepenthes waxy slippery zone are characterized by atomic force microscope (AFM) and environment scanning electron microscope (ESEM). An individual domain of the waxy slippery zone surface is scanned by AFM with different normal forces applied, showing no difference in the topography and without pollutant adhering to the probe tip after scanning. Colloidal probe, which is made by gluing a 15 μm silica sphere onto the probe cantilever equipped with no tips, is employed to behave as a single seta contacting with the surface of nepenthes waxy slippery zone. Adhesion and friction forces of the waxy zone surface are measured and compared with those of polishing papers. Considering the effect of surface physicochemical properties on its adhesion ability, contact angles of polar (water) and non-polar (diiodomethane) liquids on the waxy zone surface and polishing papers with a similar roughness are measured by contact angle measuring device. The results show that a single crystal of waxy zone is of the mechanical stability, thus disclaiming the contamination hypothesis. The contact area at the interface can be reduced efficiently by the surface roughness of waxy zone, which, to some extent, decreases its adhesion and friction forces. The super-hydrophobic property and low surface energy of the waxy zone, combined with each other to form an anti-adhesion effect on the nepenthes waxy slippery zone, are another factor in reducing the surface adhesion and friction forces.
[1] THUM M. The significant of carnivory for the fitness of Drosera in its natural habitat. 1. the reactions of Drosera intermedia and Drosera rotundifolia to supplementary feeding[J]. Oecologia，1988，75(3)：427-480.
[2] ELLISON A M，GOTELLI N J. Energetics and the evolution of carnivorous plants-Darwin’s ‘most wonderful plants in the world’[J]. J. Exp. Bot.，2009，60(1)：19-42.
[3] MORAN E A. Nutrient limitation and stoichiometry of carnivorous plants[J]. Plant Biol.，2006，8(6)：740-747.
[4] BOHN H F，FEDERLE W. Insect aquaplaning：Nepenthes pitcher plants capture prey with the peristome，a fully wettable water-lubricated anisotropic surface[J]. PANS.，2009，101(39)：4138-14143.
[5] MORAN J A，CHA，CLARK C M. The carnivorous syndrome in Nepenthes pitcher plants[J]. Plant Signaling & Behavior，2010，5(6)：644-648.
[6] GORB E，HASS K，HENRICH A，et al. Composite structure of the crystalline epicuticular wax layer of the slippery zone in the pitchers of the carnivorous plant Nepenthes alata and its effect on insect attachment[J]. Journal of Experimental Biology，2005，208(24)：4651-4662.
[7] 周强，周伟荣，王立新，等. 仿生光滑表面显微结构计算机仿真与设计[J]. 农业机械学报，2009，40(9)：201-205. ZHOU Qiang，ZHOU Weirong，WANG lixin，et al. Computer simulation and design on bionic slippery microstructure surface[J]. Journal of Agricultural Machinery，2009，40(9)：201-205.
[8] BENZ M J，GORB E V，GORB E N. Diversity of the slippery zone microstructure in pitchers of nine carnivorous Nepenthes taxa[J]. Arthropod-Plant Interactions，2012，6(1)：147-158.
[9] SCHOLZ I，BUCKINS B，DOLGE J，et al. Slipppery surface of pitcher plants：Nepenthes wax crystals minimize insect attachment via microscopic surface roughness[J]. The Journal of Experimental Biology，2009，213(8)：1115-1125.
[10] JAMES M R，BULLOCK， FEDERLE W. The effect of surface roughness on claw and adhesive hair performance in the dock beetle Gastrophysa virdula[J]. Insect Science，2011，18(3)：298-304.
[11] VOIGT D，SCHWEIKART A，FERY A. Leaf beetle attachment on wrinkles：Isotropic friction on anisotropic surfaces[J]. The Journal Experimental Biology，2012，215(12)：1975-1982.
[12] BORODICH F M，GORB E V，GORB S N. Fracture behaviour of plant epicuticular wax crystals and its role in preventing insect attachment：A theoretical approach[J]. Appl. Phys. A，2010，100(1)：63-71.
[13] KOVALEV A E，FILLIPPOV A E，GORB S N. Insect wet steps：Loss of fluid from insect feet adhering to a substrate[J]. Journal of the Royal Society Interface，2013，10 (78)：20120639.
[14] WHITNEY H M，FEDERLA W. Biomechanics of plant-insect interactions[J]. Current Opinion in Plant Biology，2013，16(1)：105-111.
[15] DUCKER W A，SENDEN T J，ASHLEY R M. Direct measurement of colloidal force using an atomic force microscope[J]. Nature，1991，353：239-241.
[16] GAN Y. Attaching spheres to Cantilevers for colloidal probe force measurements：A simplified techniques[J]. Microscope Today，2005，13(6)：48-50.
[17] GORB S N. The design of the fly adhesive pad：Distal tenent setae are adapted to the delivery of an adhesive secretion[J]. Proc. R. Soc. Lond. B，1998，265(1398)：747-752.
[18] 俞志伟，李宏凯，张晓峰，等. 仿壁虎脚趾结构设计及粘附运动性能测试[J]. 机械工程学报，2011，47(21)：7-13.YU Zhiwei，LI Hongkai，ZHANG Xiaofeng，et al. Structure design of bionic gecko’s toe and the adhesive locomotion performance test[J]. Journal of Mechanical Engineering，2011，47(21)：7-13.
[19] JOHNSON K L，KENDALL K，ROBERTS A D. Surfaces energy and contact of elastic solids[J]. Proceedings of the Royal Society of London Series A-Mathematical and Physical Science，1971，324(1558)：301.
[20] OWENS D K，WENDT R C. Estimation of surface free energy of polymers[J]. Applied Polymer Science. 1969，13(8)：1741-1747.
[21] KAELBLE D H. Dispersion-polar surface tension properties of organic solids[J]. The Journal of Adhesion，1970，2(2)：66-81.
[22] BUSSCHER H J，VANPERT A W，DEBOER P，et al. The effect of the surface roughening of polymers on measured contact angle of liquids[J]. Colloids and Surfaces，1984(9)：319-331.
[23] 陈莉，周宏，赵宇，等. 不同形态和间隔非光滑表面模具钢的磨损性能[J]. 机械工程学报，2008，44(3)：173-176. CHEN Li，ZHOU Hong，ZHAO Yu，et al. Wear behavior of die steel with non-smooth surface in different shape and distance[J]. Chinese Journal of Mechanical Engineering，2008，44(3)：173-176.
[24] 齐迎春，从茜，王骥月，等. 凹槽形仿生针头优化设计与减租机理分析[J]. 机械工程学报，2012，48(15)：126-130.QI Yingchun，CONG Qian，WANG Jiyue，et al. Optimization design and drag reduction mechanism research on groove shape bionic needle[J]. Journal of Mechanical Engineering，2012，48(15)：126-130.
[25] VOIGT D，SCHUPPERT J M，DATTINGER S，et al. Sexual dimorphism in the attachment ability of the Colorado potato beetle Leptinotarsa decemlineata (Coleoptera：Chrysomelidate) to rough substrates[J] Journal of Insect Physiology，2008，54(5)：765-776.
[26] 韩志武，邱兆美，王淑杰，等. 植物表面非光滑形态与湿润型的关系[J]. 吉林大学学报，2008，38(1)：110-115.HAN Zhiwu，QIU Zhaomei，WANG Shujie，et al. Relationship between non-appearance and wettability of plant leaf surface[J]. Journal of Jilin University，2008，38(1)：110-115.
[27] 温诗铸，黄平. 界面科学与技术[M]. 北京：清华大学出版社，2011. WEN Shizhu，HUANG Ping. Interface science and technology[M]. Beijing：Tsinghua University Press，2011.
[28] DZYALOSHINSKII I E，LIFSCHITZ E M，PITAEVSKII L P. General theory of van der Waals’force[J]. Sov. Phys. Usp.，1961，4(6)：153-176.
[29] POPOV V L. Contact mechanics and friction physical principles and applications[M]. German：Springer，2009.
