We demonstrate a novel principle of contactless actuation for ionic membranes in salt solution based on solvation. Actuation is driven by differential swelling of the sides of the membrane, due to comigrating water in the solvation shells of mobile ions. We validate our theory through a series of experiments, which unravel a strong dependence of membrane deflection on the hydration numbers of mobile ions in the external solution and membrane. Our study suggests a critical role of solvation in the chemoelectromechanics of natural and artificial selectively permeable membranes.
Bibliographical noteFunding Information:
The authors acknowledge financial support from the National Science Foundation under Grant No. OISE-1545857 and National Research Foundation of Korea (NRF) funded by the Korea government (MSIT) under Grant No. 2020R1A2C2005252. The authors are grateful to Roni Barak Ventura and Agnieszka Truszkowska for their help with experiments and useful discussion.
© 2021 American Physical Society.
ASJC Scopus subject areas
- Physics and Astronomy(all)