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Bioinspired Strategies for Water Collection and Water Purification

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Biomimetics

Part of the book series: Springer Series in Materials Science ((SSMATERIALS,volume 279))

Abstract

Fresh water sustains human life and is vital for human health. There is enough fresh water for everyone on Earth. However, due to bad economics or poor infrastructure, water scarcity affects more than 40% of the global population and is projected to rise. It is estimated that more than 800 million people do not have access to clean water and over 1.7 billion people are currently living in river basins where water use exceeds recharge.

In 2010, the United Nations General Assembly recognized the human right to water and sanitation and acknowledged that clean drinking water and sanitation are essential to the realization of all human rights.

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References

  • Agre, P., Sasaki, S., and Chrispeels, M. J. (1993), “Aquaporins: A Family of Water Channel Proteins,” Am. J. Physiol. 265, F461.

    Article  CAS  Google Scholar 

  • Andrews, H. G., Eccles, E. A., Schofield, W. C. E., and Badyal, J. P. S. (2011), “Three-Dimensional Hierarchical Structures for Fog Harvesting,” Langmuir 27, 3798–3802.

    Article  CAS  Google Scholar 

  • Anonymous (2008), Environmental Outlook to 2030, OECD Publishing, Paris, France.

    Google Scholar 

  • Anonymous (2009), “Charting Our Water Future: Economic Frameworks to Inform Decision-Making,” see http://www.2030wrg.org/wp-content/uploads/2014/07/Charting-Our-Water-Future-Final.pdf.

  • Anonymous (2015a), Water Uses, Food and Agricultural Organization of the United Nations, see http://www.fao.org/nr/water/aquastat/water_use.

  • Anonymous (2015b), Progress on Sanitation and Drinking Water, World Health Organization and UNICEF, WHO Press, Geneva, Switzerland.

    Google Scholar 

  • Bai, H., Tian, X., Zheng, Y., Ju, J., Zhao, Y., and Jiang, L. (2010), “Direction Controlled Driving of Tiny Water Drops on Bioinspired Artificial Spider Silks,” Adv. Mater. 22, 5521–5525.

    Article  CAS  Google Scholar 

  • Bai, H., Wang, L., Ju, J., Sun, R., Zheng, Y., and Jiang, L. (2014), “Efficient Water Collection on Integrative Bioinspired Surfaces with Star-Shaped Wettability Patterns,” Adv. Mater. 26, 5025–5030.

    Article  CAS  Google Scholar 

  • Bentley, P. J. and Blumer, W. F. C. (1962), “Uptake of Water by the Lizard, Moloch horridus,” Nature 194, 699–700.

    Article  CAS  Google Scholar 

  • Beresford-Jones, D., Pullen, A. G., Whaley, O. Q., Moat, J., Chauca, G., Cadwallader, L., Arce, S., Orellana, A., Alarcón, C., Gorriti, M., Maita, P. K., Sturt, F., Dupeyron, A., Huaman, O., Lane, K. J., and French, C. (2015), “Re-evaluating the Resource Potential of Lomas Fog Oasis Environments for Preceramic Hunter–gatherers under Past ENSO Modes on the South Coast of Peru,” Quat. Sci. Rev. 129, 196–215.

    Article  Google Scholar 

  • Bhushan, B. (2013), Introduction to Tribology, 2nd ed., Wiley, New York.

    Book  Google Scholar 

  • Bhushan, B. and Martin, S. (2018), “Substrate-Independent Superliquiphobic Coatings for Water, Oil, and Surfactant Repellency: An Overview,” J. Colloid Interface Sci. 526, 90–105.

    Article  CAS  Google Scholar 

  • Brown, P. S. and Bhushan, B. (2015a), “Mechanically Durable, Superoleophobic Coatings Prepared by Layer-by-Layer Technique for Anti-smudge and Oil-Water Separation,” Sci. Rep. Nat. 5, 8701.

    Google Scholar 

  • Brown, P. S. and Bhushan, B. (2015b), “Bioinspired, Roughness-Induced, Water and Oil Super-philic and Super-phobic Coatings Prepared by Adaptable Layer-by-Layer Technique,” Sci. Rep. Nat. 5, 14030.

    Google Scholar 

  • Brown, P. S. and Bhushan, B. (2016), “Bioinspired Materials for Water Supply and Management: Water Collection, Water Purification and Separation of Water from Oil,” Phil. Trans. R. Soc. A 374, 20160135.

    Article  Google Scholar 

  • Cavallo, F. and Lagally, M. G. (2010), “Semiconductors Turn Soft: Inorganic Nanomembranes,” Soft Matter 6, 439–455.

    Article  CAS  Google Scholar 

  • Cazacu, A., Tong, C., van der Lee, A., Fyles, T. M., and Barboiu, M. (2006), “Columnar Self-assembled Ureido Crown Ethers: An Example of Ion-Channel Organization in Lipid Bilayers,” J. Am. Chem. Soc. 128, 9541–9548.

    Article  CAS  Google Scholar 

  • Chen, Y., Wang, L., Xue, Y., Jiang, L., and Zheng, Y. (2013), “Bioinspired Tilt-Angle Fabricated Structure Gradient Fibers: Micro-drops Fast Transport in a Long-Distance,” Sci. Rep. 3, 2927, pp. 1–8.

    Google Scholar 

  • Comanns, P., Effertz, C., Hischen, F., Staudt, K., Böhme, W., and Baumgartner, W. (2011), “Moisture Harvesting and Water Transport Through Specialized Micro-structures on the Integument of Lizards,” Beilstein J. Nanotechnol. 2, 204–214.

    Article  CAS  Google Scholar 

  • Comanns, P., Buchberger, G., Buchbaum, A., Baumgartner, R., Kogler, A., Bauer, S., and Baumgartner, W. (2015), “Directional, Passive Liquid Transport: the Texas Horned Lizard as a Model for a Biomimetic ‘Liquid Diode’,” J. R. Soc. Interface 12, 20150415, pp. 1–8.

    Article  Google Scholar 

  • Corry, B. (2008), “Designing Carbon Nanotube Membranes for Efficient Water Desalination,” J. Phys. Chem. B 112, 1427–1434.

    Article  CAS  Google Scholar 

  • Crini, G. (2005), “Recent Developments in Polysaccharide-based Materials used as Adsorbents in Wastewater Treatment,” Prog. Polym. Sci. 30, 38–70.

    Article  CAS  Google Scholar 

  • Davis, M. E. (2002), “Ordered Porous Materials for Emerging Applications,” Nature 417, 813–820.

    Article  CAS  Google Scholar 

  • Davis, S. A., Burkett, S. L., Mendelson, N. H., and Mann, S. (1997), “Bacterial Templating of Ordered Macrostructures in Silica and Silica-Surfactant Mesophases,” Nature 385, 420–423.

    Article  CAS  Google Scholar 

  • Dong, H., Wang, N., Wang, L., Bai, H., Wu, J., Zheng, Y., Zhao, Y., and Jiang, L. (2012), “Bioinspired Electrospun Knotted Microfibers for Fog Harvesting,” ChemPhysChem 13, 1153–1156.

    Article  CAS  Google Scholar 

  • Ebner, M., Miranda, T., and Roth-Nebelsick, A. (2011), “Efficient Fog Harvesting by Stipagrostis sabulicola (Namib Dune Bushman Grass),” J. Arid Environ. 75, 524–531.

    Article  Google Scholar 

  • Edmonds, D. T. and Vollrath, F. (1992), “The Contribution of Atmospheric Water Vapour to the Formation and Efficiency of a Spider’s Capture Web,” Proc. R. Soc. Lond. B 248, 145–148.

    Article  CAS  Google Scholar 

  • Elimelech, M. and Phillip, W. A. (2011), “The Future of Seawater Desalination: Energy, Technology, and the Environment,” Science 333, 712–717.

    Article  CAS  Google Scholar 

  • EPA (1995), The Great Lakes: An Environmental Atlas and Resource Book, 3rd ed., EPA, Chicago, IL.

    Google Scholar 

  • Esmanski, A. and Ozin, G. A. (2009), “Silicon Inverse-Opal-based Macroporous Materials as Negative Electrodes for Lithium Ion Batteries,” Adv. Funct. Mater. 19, 1999–2010.

    Article  CAS  Google Scholar 

  • Fornasiero, F., Park, H. G., Holt, J. K., Stadermann, M., Grigoropoulos, C. P., Noy, A., and Bakajin, O. (2008), “Ion Exclusion by Sub-2-nm Carbon Nanotube Pores,” Proc. Natl. Acad. Sci. 105, 17250–17255.

    Article  CAS  Google Scholar 

  • Garrod, R. P., Harris, L. G., Schofield, W. C. E., McGettrick, J., Ward, L. J., Teare, D. O. H., and Badyal, J. P. S. (2007), “Mimicking a Stenocara Beetle’s Back for Microcondensation Using Plasmachemical Patterned Superhydrophobic-Superhydrophilic Surfaces,” Langmuir 23, 689–693.

    Article  CAS  Google Scholar 

  • Ghadiri, M. R., Granja, J. R., Milligan, R. A., McRee, D. E., and Khazanovich, N. (1993), “Self-assembling Organic Nanotubes Based on a Cyclic Peptide Architecture,” Nature 366, 324–327.

    Article  CAS  Google Scholar 

  • Habel, J., Hansen, M., Kynde, S., Larsen, N., Midtgaard, S. R., Jensen, G. V., Bomholt, J., Ogbonna, A., Almdal, K., Schulz, A., and Hélix-Nielsen, C. (2015), “Aquaporin-based Biomimetic Polymeric Membranes: Approaches and Challenges,” Membranes 5, 307–351.

    Article  CAS  Google Scholar 

  • Hamilton, W. J. and Seely, M. K. (1976), “Fog Basking by the Namib Desert Beetle, Onymacris unguicularis,” Nature 262, 284–285.

    Article  Google Scholar 

  • Holt, J. K., Park, H. G., Wang, Y., Stadermann, M., Artyukhin, A. B., Grigoropoulos, C. P., Noy, A., and Bakajin, O. (2006), “Fast Mass Transport through Sub-2-Nanometer Carbon Nanotubes,” Science 312, 1034–1037.

    Article  CAS  Google Scholar 

  • Hourani, R., Zhang, C., van der Weegen, R., Ruiz, L., Li, C., Keten, S., Helms, B. A., and Xu, T. (2011), “Processable Cyclic Peptide Nanotubes with Tunable Interiors,” J. Am. Chem. Soc. 133, 15296–15299.

    Article  CAS  Google Scholar 

  • Hummer, G., Rasaiah, J. C., and Noworyta, J. P. (2001), “Water Conduction Through the Hydrophobic Channel of a Carbon Nanotube,” Nature 414, 188–190.

    Article  CAS  Google Scholar 

  • Ju, J., Bai, H., Zheng, Y., Zhao, T., Fang, R., and Jiang, L. (2012), “A Multi-structural and Multi-functional Integrated Fog Collection System in Cactus,” Nat. Commun. 3, Art. 247.

    Google Scholar 

  • Ju, J., Xiao, K., Yao, X., Bai, H., and Jiang, L. (2013), “Bioinspired Conical Copper Wire with Gradient Wettability for Continuous and Efficient Fog Collection,” Adv. Mater. 25, 5937–5942.

    Article  CAS  Google Scholar 

  • Ju, J., Yao, X., Yang, S., Wang, L., Sun, R., He, Y., and Jiang, L. (2014), “Cactus Stem Inspired Cone-Arrayed Surfaces for Efficient Fog Collection,” Adv. Funct. Mater. 24, 6933–6938.

    Article  CAS  Google Scholar 

  • Lee, K. P., Arnot, T. C., and Mattia, D. (2011), “A Review of Reverse Osmosis Membrane Materials for Desalination—Development to Date and Future Potential,” J. Membr. Sci. 370, 1–22.

    Article  CAS  Google Scholar 

  • Liu, G. and Ding, J. (1998), “Diblock Thin Films with Densely Hexagonally Packed Nanochannels,” Adv. Mater. 10, 69–71.

    Article  CAS  Google Scholar 

  • Liu, C., Xue, Y., Chen, Y., and Zheng, Y. (2015), “Effective Directional Self-gathering of Drops on Spine of Cactus with Splayed Capillary Arrays,” Sci. Rep. 5, 17757, pp. 1–8.

    Google Scholar 

  • Lorenceau, É. and Quéré, D. (2004), “Drops on a Conical Wire,” J. Fluid Mech. 510, 29–45.

    Article  Google Scholar 

  • Louw, G. N. and Seely, M. K. (1980), “Exploitation of Fog Water by a Perennial Namib Dune Grass, Stipagrotis sabulicola,” S. Afr. J. Sci. 76, 38–39.

    Google Scholar 

  • Ma, W., Samal, S. K., Liu, Z., Xiong, R., De Smedt, S. C., Bhushan, B., Zhang, Q., and Huang, C. (2017), “Dual pH- and Ammonia-Vapor-Responsive Electrospun Nanofibrous Membranes for Oil-Water Separations,” J. Membr. Sci. 537, 128–139.

    Article  CAS  Google Scholar 

  • Mondal, B., Eain, M. M. G., Xu, Q, Egan, V. M., Punch, J., and Lyons, A. M. (2015), “Design and Fabrication of a Hybrid Superhydrophobic–Hydrophilic Surface That Exhibits Stable Dropwise Condensation,” ACS Appl. Mater. Interfaces 7, 23575–23588.

    Article  CAS  Google Scholar 

  • Mooney, H. A., Weisser, P. J., and Gulmon, S. L. (1977), “Environmental Adaptations of the Atacama Desert Cactus Copiapoa haseltoniana,” Flora 166, 117–124.

    Article  Google Scholar 

  • Negin, S., Daschbach, M. M., Kulikov, O. V., Rath, N., and Gokel, G. W. (2011), “Pore Formation in Phospholipid Bilayers by Branched-Chain Pyrogallol[4]arenes,” J. Am. Chem. Soc. 133, 3234–3237.

    Article  CAS  Google Scholar 

  • Ogasawara, W., Shenton, W., Davis, S. A., and Mann, S. (2000), “Template Mineralization of Ordered Macroporous Chitin–Silica Composites Using a Cuttlebone-Derived Organic Matrix,” Chem. Mater. 12, 2835–2837.

    Article  CAS  Google Scholar 

  • Ogburn, R. M. and Edwards, E. J. (2009), “Anatomical Variation in Cactaceae and Relatives: Trait Lability and Evolutionary Innovation,” Am. J. Bot. 96, 391–408.

    Article  Google Scholar 

  • Park, K.-C., Chhatre, S. S., Srinivasan, S., Cohen, R. E., and McKinley, G. H. (2013), “Optimal Design of Permeable Fiber Network Structures for Fog Harvesting,” Langmuir 29, 13269–13277.

    Article  CAS  Google Scholar 

  • Parker, A. R. and Lawrence, C. R. (2001), “Water Capture by a Desert Beetle,” Nature 414, 33–34.

    Article  CAS  Google Scholar 

  • Peinemann, K.-V., Abetz, V., and Simon, P. F. W. (2007), “Asymmetric Superstructure Formed in a Block Copolymer via Phase Separation,” Nat. Mater. 6, 992–996.

    Article  CAS  Google Scholar 

  • Percec, V., Dulcey, A. E., Balagurusamy, V. S. K., Miura, Y., Smidrkal, J., Peterca, M., Nummelin, S., Edlund, U., Hudson, S. D., Heiney, P. A., Duan, H., Magonov, S. N., and Vinogradov, S. A. (2004), “Self-assembly of Amphiphilic Dendritic Dipeptides into Helical Pores,” Nature 430, 764–768.

    Article  CAS  Google Scholar 

  • Percec, V., Dulcey, A. E., Peterca, M., Adelman, P., Samant, R., Balagurusamy, V. S. K., and Heiney, P. A. (2007), “Helical Pores Self-assembled from Homochiral Dendritic Dipeptides Based on l-Tyr and Nonpolar α-Amino Acids,” J. Am. Chem. Soc. 129, 5992–6002.

    Article  CAS  Google Scholar 

  • Phillip, W. A., Hillmyer, M. A., and Cussler, E. L. (2010), “Cylinder Orientation Mechanism in Block Copolymer Thin Films Upon Solvent Evaporation,” Macromolecules 43, 7763–7770.

    Article  CAS  Google Scholar 

  • Pollard, S. J. T., Fowler, G. D., Sollars, C. J., and Perry, R. (1992), “Low-Cost Adsorbents for Waste and Waste-Water Treatment—A Review,” Sci. Total Environ. 116, 31–52.

    Google Scholar 

  • Roth-Nebelsick, A., Ebner, M., Miranda, T., Gottschalk, V., Voigt, D., Gorb, S., Stegmaier, T., Sarsour, J., Linke, M., and Konrad, W. (2012), “Leaf Surface Structures Enable the Endemic Namib Desert Grass Stipagrostis sabulicola to Irrigate Itself with Fog Water,” J. R. Soc. Interface 9, 1965–1974.

    Article  CAS  Google Scholar 

  • Schwenk, K. and Greene, H. W. (1987), “Water Collection and Drinking in Phrynocephalus helioscopus: A Possible Condensation Mechanism,” J. Herpetol. 21, 134–139.

    Article  Google Scholar 

  • Sengur-Tasdemir, R., Aydin, S., Turken, T., Genceli, E. A., and Koyuncu, I. (2016), “Biomimetic Approaches for Membrane Technologies,” Sep. Purif. Rev. 45, 122–140.

    Article  Google Scholar 

  • Shannon, M. A., Bohn, P. W., Elimelech, M., Georgiadis, J. G., Mariñas, B. J., and Mayes, A. M. (2008), “Science and Technology for Water Purification in the Coming Decades,” Nature 452, 301–310.

    Article  CAS  Google Scholar 

  • Shanyengana, E. S., Henschel, J. R., Seely, M. K., and Sanderson, R. D. (2002), “Exploring Fog as a Supplementary Water Source in Namibia,” Atmos. Res. 64, 251–259.

    Article  CAS  Google Scholar 

  • Shiklomanov, I. A. (1993), “World Fresh Water Resources,” in Water in Crisis: A Guide to the World’s Fresh Water Resources (ed. P. H. Gleick), p. 13, Oxford University Press, New York.

    Google Scholar 

  • Shin, Y., Liu, J., Chang, J. H., Nie, Z., and Exarhos, G. J. (2001), “Hierarchically Ordered Ceramics Through Surfactant-Templated Sol-Gel Mineralization of Biological Cellular Structures,” Adv. Mater. 13, 728–732.

    Article  CAS  Google Scholar 

  • Shin, Y., Wang, L.-Q., Chang, J. H., Samuels, W. D., and Exarhos, G. J. (2003), “Morphology Control of Hierarchically Ordered Ceramic Materials Prepared by Surfactant-Directed Sol-Gel Mineralization of Wood Cellular Structures,” Stud. Surf. Sci. Catal. 146, 447–451.

    Google Scholar 

  • Srivastava, A., Srivastava, O. N., Talapatra, S., Vajtai, R., and Ajayan, P. M. (2004), “Carbon Nanotube Filters,” Nat. Mater. 3, 610–614.

    Article  CAS  Google Scholar 

  • Surwade, S. P., Smirnov, S. N., Vlassiouk, I. V., Unocic, R. R., Veith, G. M., Dai, S., and Mahurin, S. M. (2015), “Water Desalination using Nanoporous Single-Layer Graphene,” Nat. Nanotechnol. 10, 459–464.

    Article  CAS  Google Scholar 

  • Taguchi, A. and Schüth, F. (2005), “Ordered Mesoporous Materials in Catalysis,” Micropor. Mesopor. Mater. 77, 1–45.

    Article  CAS  Google Scholar 

  • Verkman, A. S., Anderson, M. O., and Papadopoulos, M. C. (2014), “Aquaporins: Important but Elusive Drug Targets,” Nat. Rev. Drug Discov. 13, 259–277.

    Article  CAS  Google Scholar 

  • Vesilind, P. J. (2003), “Atacama Desert,” National Geographic (August, 2003) see http://ngm.nationalgeographic.com/features/world/south-america/chile/atacama-text.

  • Wang, S. and Peng, Y. (2010), “Natural Zeolites as Effective Adsorbents in Water and Wastewater Treatment,” Chem. Eng. J. 156, 11–24.

    Article  CAS  Google Scholar 

  • Wang, Y., Zhang, L., Wu, J., Hedhili, M. N., and Wang, P. (2015), “A Facile Strategy for the Fabrication of a Bioinspired Hydrophilic–superhydrophobic Patterned Surface for Highly Efficient Fog-Harvesting,” J. Mater. Chem. A 3, 18963–18969.

    Article  CAS  Google Scholar 

  • Wong, I., Teo, G. H., Neto, C., and Thickett, S. C. (2015), “Micropatterned Surfaces for Atmospheric Water Condensation via Controlled Radical Polymerization and Thin Film Dewetting,” ACS Appl. Mater. Interfaces 7, 21562–21570.

    Article  CAS  Google Scholar 

  • Xue, Y., Wang, T., Shi, W., Sun, L., and Zheng, Y. (2014), “Water Collection Abilities of Green Bristlegrass Bristle,” RSC Adv. 4, 40837–40840.

    Article  CAS  Google Scholar 

  • Yang, D., Qi, L., and Ma, J. (2002), “Eggshell Membrane Templating of Hierarchically Ordered Macroporous Networks Composed of TiO2 Tubes,” Adv. Mater. 14, 1543–1546.

    Article  CAS  Google Scholar 

  • Zhang, B., Davis, S. A., and Mann, S. (2002), “Starch Gel Templating of Spongelike Macroporous Silicalite Monoliths and Mesoporous Films,” Chem. Mater. 14, 1369–1375.

    Article  CAS  Google Scholar 

  • Zhao, Y., Qiu, C., Li, X., Vararattanavech, A. Shen, W. Torres, J., Hélix-Nielsen, C., Wang, R., Hu, X., Fane, A. G., and Tang, C. Y. (2012), “Synthesis of Robust and High-Performance Aquaporin-based Biomimetic Membranes by Interfacial Polymerization-Membrane Preparation and RO Performance Characterization,” J. Membr. Sci. 423–424, 422–428.

    Article  CAS  Google Scholar 

  • Zheng, Y., Bai, H., Huang, Z., Tian, X., Nie, F.-Q., Zhao, Y., Zhai, J., and Jiang, L. (2010), “Directional Water Collection on Wetted Spider Silk,” Nature 463, 640–643.

    Article  CAS  Google Scholar 

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  1. Nanoprobe Laboratory for Bio/Nanotechnology and Biomimetics (NLBB), The Ohio State University, Columbus, OH, USA

    Bharat Bhushan

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Appendix: Laplace Pressure Gradient on a Conical Surface

Appendix: Laplace Pressure Gradient on a Conical Surface

For a spherical droplet sitting on a surface, capillary pressure or Laplace pressure in the liquid \( p_{L} \) is proportional to the surface tension of the liquid in air (\( \gamma_{LA} \)) divided by the local radius, R (Bhushan 2013),

$$ p_{L} = \frac{{\gamma_{LA} }}{R} $$
(17.1)

The Laplace pressure can be attractive or repulsive depending on whether the surface is hydrophilic or hydrophobic , respectively. The \( p_{L} \) remains constant on a flat surface.

Next, we consider a liquid droplet sitting on a conical object. We consider two adjacent locations A and B with the local radii of the cone, as RA and RB, respectively, Fig. 17.27. The substrate curvature gradient results in the Laplace pressure difference between the two opposite ends of the droplet along the surface. The Laplace pressure difference is given as

Fig. 17.27
figure 27

Schematic of a liquid droplet on conical object with a cone angle of 2α and local radii RA and RB at two locations of A and B, respectively. Shown is the Laplace force (FL) which helps in driving the droplet towards a larger radius

Full size image
$$ \Delta p_{L} = \gamma_{LA} \left( {\frac{1}{{R_{B}^{'} }} - \frac{1}{{R_{A}^{'} }}} \right) $$
(17.2)

where \( R_{A}^{'} \) and \( R_{B}^{'} \) are the radii of curvature at the rear and front contact lines of the droplet, respectively. The curvature gradient leading to Laplace pressure difference which acts on the contact area \( \Omega \), produces the Laplace force FL,

$$ F_{L} = \iint\limits_{\Omega } {\Delta p_{L} {\text{d}}\Omega } $$
(17.3)

where the contact area is approximately equal to volume of the droplet, \( V_{droplet} \) divided by the length L of the droplet,

$$ \Omega \sim\frac{\sin \alpha }{{\left( {R_{A} - R_{B} } \right)}}V_{droplet} $$
(17.4)

where α is the half apex angle of the cone. Using (17.2)–(17.4), we get

$$ F_{L} \sim\gamma_{LA} \left( {\frac{1}{{R_{B}^{'} }} - \frac{1}{{R_{A}^{'} }}} \right)\frac{\sin \alpha }{{R_{A} - R_{B} }}V_{droplet} $$
(17.5)

The Laplace force acting on a conical object drives the droplet from regions of lower radius to larger radius. As the droplet moves away from the region, a new droplet can get condensed and provide the continuous movement.

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Bhushan, B. (2018). Bioinspired Strategies for Water Collection and Water Purification. In: Biomimetics. Springer Series in Materials Science, vol 279. Springer, Cham. https://doi.org/10.1007/978-3-319-71676-3_17

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