Harvesting energy from the environment offers the promise of clean power for self-sustained systems1,2. Known technologies—such as solar cells, thermoelectric devices and mechanical generators—have specific environmental requirements that restrict where they can be deployed and limit their potential for continuous energy production3,4,5. The ubiquity of atmospheric moisture offers an alternative. However, existing moisture-based energy-harvesting technologies can produce only intermittent, brief (shorter than 50 seconds) bursts of power in the ambient environment, owing to the lack of a sustained conversion mechanism6,7,8,9,10,11,12. Here we show that thin-film devices made from nanometre-scale protein wires harvested from the microbe Geobacter sulfurreducens can generate continuous electric power in the ambient environment. The devices produce a sustained voltage of around 0.5 volts across a 7-micrometre-thick film, with a current density of around 17 microamperes per square centimetre. We find the driving force behind this energy generation to be a self-maintained moisture gradient that forms within the film when the film is exposed to the humidity that is naturally present in air. Connecting several devices linearly scales up the voltage and current to power electronics. Our results demonstrate the feasibility of a continuous energy-harvesting strategy that is less restricted by location or environmental conditions than other sustainable approaches.
This is a preview of subscription content, access via your institution
Open Access articles citing this article.
Transfer learning enhanced water-enabled electricity generation in highly oriented graphene oxide nanochannels
Nature Communications Open Access 10 November 2022
Nature Communications Open Access 24 August 2022
Nature Communications Open Access 28 July 2022
Subscribe to Nature+
Get immediate online access to Nature and 55 other Nature journal
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Get time limited or full article access on ReadCube.
All prices are NET prices.
The data that support the findings of this study are available within the paper and Supplementary Information. Additional supporting data generated during the present study are available from the corresponding author upon reasonable request.
Tentzeris, M. M., Georgiadis, A. & Roselli, L. Energy harvesting and scavenging. Proc. IEEE 102, 1644–1648 (2014).
Abowd, G. D. & Mynatt, E. D. Charting past, present, and future research in ubiquitous computing. ACM Trans. Comput. Hum. Interact. 7, 29–58 (2000).
Parida, B., Iniyan, S. & Goic, R. A review of solar photovoltaic technologies. Renew. Sustain. Energy Rev. 15, 1625–1636 (2011).
Wang, Z. L. Triboelectric nanogenerators as new energy technology for self-powered systems and active mechanical and chemical sensors. ACS Nano 7, 9533–9557 (2013).
Champier, D. Thermoelectric generators: a review of applications. Energy Convers. Manage. 140, 167–181 (2017).
Zhao, F., Cheng, H., Zhang, Z., Jiang, L. & Qu, L. Direct power generation from a graphene oxide film under moisture. Adv. Mater. 27, 4351–4357 (2015).
Xue, J. et al. Vapor-activated power generation on conductive polymer. Adv. Funct. Mater. 26, 8784–8792 (2016).
Zhao, F., Liang, Y., Cheng, H., Jiang, L. & Qu, L. Highly efficient moisture-enabled electricity generation from graphene oxide frameworks. Energy Environ. Sci. 9, 912–916 (2016).
Ding, T. et al. All-printed porous carbon film for electricity generation from evaporation-driven water flow. Adv. Funct. Mater. 27, 1700551 (2017).
Shen, D. et al. Self-powered wearable electronics based on moisture enabled electricity generation. Adv. Mater. 30, 1705925 (2018).
Liu, K. et al. Induced potential in porous carbon films through water vapor adsorption. Angew. Chem. Int. Edn 55, 8003–8007 (2016).
Cheng, H. et al. Spontaneous power source in ambient air of a well-directionally reduced graphene oxide bulk. Energy Environ. Sci. 11, 2839–2845 (2018).
Xue, G. et al. Water-evaporation-induced electricity with nanostructured carbon materials. Nat. Nanotechnol. 12, 317–321 (2017).
Zhang, Z. et al. Emerging hydrovoltaic technology. Nat. Nanotechnol. 13, 1109–1119 (2018).
Lovley, D. R. Electrically conductive pili: biological function and potential applications in electronics. Curr. Opin. Electrochem 4, 190–198 (2017).
Lovley, D. R. e-Biologics: fabrication of sustainable electronics with “green” biological materials. MBio 8, e00695 (2017).
Lovley, D. R. & Walker, D. J. F. Geobacter protein nanowires. Front. Microbiol. 10, 2078 (2019).
Malvankar, N. S. et al. Tunable metallic-like conductivity in microbial nanowire networks. Nat. Nanotechnol. 6, 573–579 (2011).
Adhikari, R. Y., Malvankar, N. S., Tuominen, M. T. & Lovley, D. R. Conductivity of individual Geobacter pili. RSC Adv. 6, 8354–8357 (2016).
Filman, D. J. et al. Cryo-EM reveals the structural basis of long-range electron transport in a cytochrome-based bacterial nanowire. Commun. Biol. 2, 219 (2019).
Wang, F. et al. Structure of microbial nanowires reveals stacked hemes that transport electrons over micrometers. Cell 177, 361–369 (2019).
Feliciano, G. T., Steidl, R. J. & Reguera, G. Structural and functional insights into the conductive pili of Geobacter sulfureducens revealed in molecular dynamics simulations. Phys. Chem. Chem. Phys. 17, 22217 (2015).
Xiao, K. et al. Low energy atomic models suggesting a pilus structure that could account for electrical conductivity of Geobacter sulfurredecens pili. Sci. Rep. 6, 23385 (2016).
Ho, C. K. & Webb, S. W. Gas Transport in Porous Media (Springer, 2006).
Soares, L. C., Bertazzo, S., Burgo, T. A. L., Baldim, V. & Galembeck, F. A new mechanism for the electrostatic charge build-up and dissipation in dielectrics. J. Braz. Chem. Soc. 19, 277–286 (2008).
Gouveia, R. F. & Galembeck, F. Electrostatic charging of hydrophilic particles due to water adsorption. J. Am. Chem. Soc. 131, 11381–11386 (2009).
Ducati, T. R. D., Simoes, L. H. & Galembeck, F. Charge partitioning at gas-solid interfaces: humidity causes electricity buildup on metals. Langmuir 26, 13763–13766 (2010).
Perkins, R. S. Rate laws for elementary chemical reactions. J. Chem. Educ. 51, 254 (1974).
Wright, S. H. Generation of resting membrane potential. Adv. Physiol. Educ. 28, 139–142 (2004).
Yin, B., Liu, X., Gao, H., Fu, T. & Yao, J. Bioinspired and bristled microparticles for ultrasensitive pressure and strain sensors. Nat. Commun. 9, 5161 (2018).
Vargas, M. et al. Aromatic amino acids required for pili conductivity and long-range extracellular electron transport in Geobacter sulfurreducens. MBio 4, e00105-13 (2013); erratum 4, e00210-13 (2013).
Xiang, J. et al. Ge/Si nanowire heterostructures as high-performance field-effect transistors. Nature 441, 489–493 (2006).
Yao, J. et al. Nanowire nanocomputer as a finite-state machine. Proc. Natl Acad. Sci. USA 111, 2431–2435 (2014).
Esteve-Núñez, A., Rothermich, M. M., Sharma, M. & Lovley, D. R. Growth of Geobacter sulfurreducens under nutrient-limiting conditions in continuous culture. Environ. Microbiol. 7, 641–648 (2005).
Coppi, M. V., Leang, C., Sandler, S. J. & Lovley, D. R. Development of a genetic system for Geobacter sulfurreducens. Appl. Environ. Microbiol. 67, 3180–3187 (2001).
Tan, Y. et al. Expressing the Geobacter metallireducens PilA in Geobacter sulfurreducens yields pili with exceptional conductivity. MBio 8, e02203-16 (2017).
Tan, Y. et al. Synthetic biological protein nanowires with high conductivity. Small 12, 4481–4485 (2016).
Feng, J. et al. Giant moisture responsiveness of VS2 ultrathin nanosheets for novel touchless positioning interface. Adv. Mater. 24, 1969–1974 (2012).
Brooks, B. R. et al. CHARMM: the biomolecular simulation program. J. Comput. Chem. 30, 1545–1614 (2009).
Huang, J. et al. CHARMM36m: an improved force field for folded and intrinsically disordered proteins. Nat. Methods 14, 71–73 (2017).
Smart, O. S., Neduvelil, J. G., Wang, X., Wallace, B. A. & Sansom, M. S. P. HOLE: a program for the analysis of the pore dimensions of ion channel structural models. J. Mol. Graph. Model. 14, 354–360 (1996).
J.Y. and D.R.L. acknowledge support from a seed fund through the Office of Technology Commercialization and Ventures at the University of Massachusetts, Amherst. J.C. and Xiaorong L. acknowledge support from the National Institutes of Health (grant GM114300 to J.C.). Part of the device fabrication work was conducted in the Center for Hierarchical Manufacturing (CHM), a National Science Foundation (NSF) Nanoscale Science and Engineering Center (NSEC) located at the University of Massachusetts Amherst.
The authors declare no competing interests.
Peer review information Nature thanks Liangti Qu and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Liu, X., Gao, H., Ward, J.E. et al. Power generation from ambient humidity using protein nanowires. Nature 578, 550–554 (2020). https://doi.org/10.1038/s41586-020-2010-9
This article is cited by
Advanced Composites and Hybrid Materials (2023)
Nano Research (2023)
Nature Communications (2022)
Nature Reviews Microbiology (2022)
Nature Communications (2022)