Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

The transpiration of water at negative pressures in a synthetic tree

Abstract

Plant scientists believe that transpiration—the motion of water from the soil, through a vascular plant, and into the air—occurs by a passive, wicking mechanism. This mechanism is described by the cohesion-tension theory: loss of water by evaporation reduces the pressure of the liquid water within the leaf relative to atmospheric pressure; this reduced pressure pulls liquid water out of the soil and up the xylem to maintain hydration1,2,3. Strikingly, the absolute pressure of the water within the xylem is often negative, such that the liquid is under tension and is thermodynamically metastable with respect to the vapour phase1,4. Qualitatively, this mechanism is the same as that which drives fluid through the synthetic wicks that are key elements in technologies for heat transfer5, fuel cells6,7 and portable chemical systems8,9,10. Quantitatively, the differences in pressure generated in plants to drive flow can be more than a hundredfold larger than those generated in synthetic wicks. Here we present the design and operation of a microfluidic system formed in a synthetic hydrogel. This synthetic ‘tree’ captures the main attributes of transpiration in plants: transduction of subsaturation in the vapour phase of water into negative pressures in the liquid phase, stabilization and flow of liquid water at large negative pressures (-1.0 MPa or lower), continuous heat transfer with the evaporation of liquid water at negative pressure, and continuous extraction of liquid water from subsaturated sources. This development opens the opportunity for technological uses of water under tension and for new experimental studies of the liquid state of water.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Transpiration of water at negative pressures.
Figure 2: Liquid water in equilibrium with subsaturated vapours.
Figure 3: Transpiration through a synthetic tree.

References

  1. Boehm, J. Capillaritat und Saftsteigen. Ber. Dtsch. Bot. Ges. 11, 203–212 (1893)

    Google Scholar 

  2. Dixon, H. H. & Joly, J. On the ascent of sap. Phil. Trans. R. Soc. Lond. B 186, 563–576 (1895)

    Article  ADS  Google Scholar 

  3. Nobel, P. S. Physicochemical and Environmental Plant Physiology 2nd edn (Academic, 1999)

    Google Scholar 

  4. Scholander, P. F., Hammel, H. T., Bradstreet, E. D. & Hemmingsen, E. A. Sap pressure in vascular plants: Negative hydrostatic pressure can be measured in plants. Science 148, 339–346 (1965)

    Article  ADS  CAS  Google Scholar 

  5. Peterson, G. P. An Introduction to Heat Pipes: Modeling, Testing, and Applications (Wiley, 1994)

    Google Scholar 

  6. Chen, J., Matsuura, T. & Hori, M. Novel gas diffusion layer with water management function for PEMFC. J. Power Sources 131, 155–161 (2004)

    Article  ADS  CAS  Google Scholar 

  7. Karan, K. et al. An experimental investigation of water transport in PEMFCs: The role of microporous layers. Electrochem. Solid State Lett. 10, B34–B38 (2007)

    Article  CAS  Google Scholar 

  8. Effenhauser, C. S., Harttig, H. & Kramer, P. An evaporation-based disposable micropump concept for continuous monitoring applications. Biomed. Microdevices 4, 27–32 (2002)

    Article  Google Scholar 

  9. Guan, Y. X., Xu, Z. R., Dai, J. & Fang, Z. L. The use of a micropump based on capillary and evaporation effects in a microfluidic flow injection chemiluminescence system. Talanta 68, 1384–1389 (2006)

    Article  CAS  Google Scholar 

  10. Juncker, D. et al. Autonomous microfluidic capillary system. Anal. Chem. 74, 6139–6144 (2002)

    Article  CAS  Google Scholar 

  11. Atkins, P. & de Paula, J. Physical Chemistry 7th edn (Oxford Univ. Press, 2002)

    Google Scholar 

  12. Jacobsen, A. L., Pratt, R. B., Ewers, F. W. & Davis, S. D. Cavitation resistance among 26 chaparral species of southern California. Ecol. Monogr. 77, 99–115 (2007)

    Article  Google Scholar 

  13. Debenedetti, P. G. Metastable Liquids (Princeton Univ. Press, 1996)

    Google Scholar 

  14. Caupin, F. & Herbert, E. Cavitation in water: A review. C. R. Phys. 7, 1000–1007 (2006)

    Article  ADS  CAS  Google Scholar 

  15. Hayward, A. T. J. Mechanical pump with a suction lift of 17 metres. Nature 225, 376–377 (1970)

    Article  ADS  Google Scholar 

  16. Askenasy, E. Beitrage zur Erklarung des Saftsteigens. Verh. Naturhist. Med. Ver. Heidelberg 5, 429–448 (1896)

    Google Scholar 

  17. Guan, Y. & Fredlund, D. G. Use of the tensile strength of water for the direct measurement of high soil suction. Can. Geotech. J. 34, 604–614 (1997)

    Article  Google Scholar 

  18. Aybar, H. S., Egelioglu, F. & Atikol, U. An experimental study on an inclined solar water distillation system. Desalination 180, 285–289 (2005)

    Article  CAS  Google Scholar 

  19. Thut, H. F. Demonstration of the lifting power of evaporation. Ohio J. Sci. 28, 292–298 (1928)

    Google Scholar 

  20. Machin, W. D. A simple method for the generation of negative pressure in liquids. Can. J. Chem. Rev. Can. Chim. 76, 1578–1580 (1998)

    CAS  Google Scholar 

  21. Flory, P. J. Principles of Polymer Chemistry (Cornell Univ. Press, 1955)

    Google Scholar 

  22. Arce, A., Fornasiero, F., Rodriguez, O., Radke, C. J. & Prausnitz, J. M. Sorption and transport of water vapor in thin polymer films at 35 degrees C. Phys. Chem. Chem. Phys. 6, 103–108 (2004)

    Article  CAS  Google Scholar 

  23. Brinker, C. J. & Scherer, G. W. Sol-gel Science: The Physics and Chemistry of Sol-Gel Processing (Academic, 1989)

    Google Scholar 

  24. Herbert, E., Balibar, S. & Caupin, F. Cavitation pressure in water. Phys. Rev. E 74, 041603 (2006)

    Article  ADS  Google Scholar 

  25. Zwieniecki, M. A., Melcher, P. J. & Holbrook, N. M. Hydrogel control of xylem hydraulic resistance in plants. Science 291, 1059–1062 (2001)

    Article  ADS  CAS  Google Scholar 

  26. Holbrook, N. M. & Zwieniecki, M. A. Embolism repair and xylem tension: Do we need a miracle? Plant Physiol. 120, 7–10 (1999)

    Article  CAS  Google Scholar 

  27. Errington, J. R. & Debenedetti, P. G. Relationship between structural order and the anomalies of liquid water. Nature 409, 318–321 (2001)

    Article  ADS  CAS  Google Scholar 

  28. McDonald, J. C. & Whitesides, G. M. Poly(dimethylsiloxane) as a material for fabricating microfluidic devices. Acc. Chem. Res. 35, 491–499 (2002)

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank M. A. Zwieniecki, N. M. Holbrook, P. J. Melcher, C. Cohen, K. J. Niklas, C. Cottin-Bizonne, A. Lassiter and F. Caupin for discussions and suggestions. We thank G. Swan and E. Velez-Rosa for technical assistance with experiments. Support was provided by the Office of Naval Research Young Investigator Program and the Camille and Henry Dreyfus Foundation. T.D.W. acknowledges partial support by a graduate fellowship from the Corning Foundation. The experiments made use of the following facilities: Cornell NanoScale Science and Technology Facility (a member of the National Nanotechnology Infrastructure Network, supported by the National Science Foundation (NSF)), the Nanobiotechnology Center (supported by the STC Program of the NSF under Agreement No. ECS-98767710) and the Cornell Center for Materials Research (supported by the NSF under Award No. DMR-0520404).

Author Contributions A.D.S. conceived the project. Both authors designed the experiments. T.D.W. executed the experiments. Both authors wrote the manuscript.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Abraham D. Stroock.

Supplementary information

Supplementary Information

The file contains Supplementary Methods, Supplementary Figures 1-2, Supplementary Tables 1-2, Supplementary Equations S1-S11 and Supplementary Notes which contain additional information on assumptions stated in the text as well as the derivation of the mathematical relations that are presented in the text. (PDF 354 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Wheeler, T., Stroock, A. The transpiration of water at negative pressures in a synthetic tree. Nature 455, 208–212 (2008). https://doi.org/10.1038/nature07226

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature07226

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing