Ion-exchange membranes are polymers in which one of the two species is fixed, while the other can move throughout. Cation-exchange membranes, with fixed negative charges, have been widely used for applications as artificial muscles in soft robots. On the other hand, anion-exchange membranes, with fixed positive charges, have been seldom used for this purpose.
In their new paper, our own postdoctoral associated Alain Boldini and Prof. Maurizio Porfiri, in collaboration with the former visiting student Nicco Ulbricht, Prof. Chulsung Bae from Rensselaer Polytechnic Institute, and Prof. Thomas Wallmersperger from Technical University of Dresden, demonstrated the first use of anion-exchange membranes as contactless actuators in salt solution, under the influence of an external electric field. Actuation is due to solvation, the electrostatic interaction between ions and solvent molecules in the salt solution and in the membrane.
Read the full paper “Solvation-Driven Actuation of Anion-Exchange Membranes” published in Advanced Materials Interfaces here.
Image credit: Alain Boldini and Maurizio Porfiri.