Vapor-Driven Propulsion of Catalytic Micromotors
Abstract
Chemically-powered micromotors offer exciting opportunities in diverse fields, including therapeutic delivery, environmental remediation, and nanoscale manufacturing. However, these nanovehicles require direct addition of high concentration of chemical fuel to the motor solution for their propulsion. We report the efficient vapor-powered propulsion of catalytic micromotors without direct addition of fuel to the micromotor solution. Diffusion of hydrazine vapor from the surrounding atmosphere into the sample solution is instead used to trigger rapid movement of iridium-gold Janus microsphere motors. Such operation creates a new type of remotely-triggered and powered catalytic micro/nanomotors that are responsive to their surrounding environment. This new propulsion mechanism is accompanied by unique phenomena, such as the distinct off-on response to the presence of fuel in the surrounding atmosphere, and spatio-temporal dependence of the motor speed borne out of the concentration gradient evolution within the motor solution. The relationship between the motor speed and the variables affecting the fuel concentration distribution is examined using a theoretical model for hydrazine transport, which is in turn used to explain the observed phenomena. The vapor-powered catalytic micro/nanomotors offer new opportunities in gas sensing, threat detection, and environmental monitoring, and open the door for a new class of environmentally-triggered micromotors.
Additional Information
© 2015 Macmillan Publishers Limited, part of Springer Nature. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ Received:09 April 2015. Accepted:20 July 2015. Published online:18 August 2015. This project received support from the Defense Threat Reduction Agency-Joint Science and Technology Office for Chemical and Biological Defense (Grant no. HDTRA1-13-1-0002), UCSD Calit2 Strategic Research Opportunities (CSRO) program (to J.W.) and from NSF Grant No. CBET-1151590 (to D.S.). R.D. and T.X. acknowledges the China Scholarship Council (CSC) for financial support. The authors thank M. Kang and J. Uy for their help. Author Contributions: R.D., I.R. and J.L. performed the experiments. J.L., T.X., I.R., B.E., B.R., C.C. and W.G. analysed the data. B.E., D.S. performed the modelling. J.L., R.D., I.R., B.E. and J.W. wrote the manuscript. All the authors discussed the results and commented on the manuscript. The authors declare no competing financial interests.Attached Files
Published - srep13226.pdf
Supplemental Material - srep13226-s1.pdf
Supplemental Material - srep13226-s2.mov
Supplemental Material - srep13226-s3.mov
Supplemental Material - srep13226-s4.mov
Supplemental Material - srep13226-s5.mov
Supplemental Material - srep13226-s6.mov
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Additional details
- PMCID
- PMC4540091
- Eprint ID
- 81774
- Resolver ID
- CaltechAUTHORS:20170922-151718229
- HDTRA1-13-1-0002
- Defense Threat Reduction Agency (DTRA)
- CBET-1151590
- NSF
- China Scholarship Council
- Created
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2017-09-23Created from EPrint's datestamp field
- Updated
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2023-09-28Created from EPrint's last_modified field