High-Performance Electrochemical Adhesives Enabled by Perfluorinated Sulfonic-Acid Ionomers with Precise Adhesion...

Electrically switchable adhesion enables the dynamic and on-demand modulation of adhesion through electrical control. Herein, a new class of electrochemical adhesives based on the perfluoro-sulfonic acid (PFSA) ionomers is presented, which deliver robust adhesion with precise tunability through modulation of the applied charge density. Remarkably, once activated, these adhesives maintain strong adhesion without continuous power input, enabling long-term programmable bonding. Electrochemically tunable adhesion between PFSA ionomers and copper substrates is investigated. A positive potential to the copper substrate promotes sulfonate-copper coordination at the interface, resulting in strong adhesion, whereas a negative bias triggers detachment. Fracture mechanics analysis reveals a linear relationship between the critical energy release rate (G_c) and applied charge density (q) with a value of 3.2  ×  10^-2 J C^-1, confirming that electrochemical reactions govern adhesion and can be precisely modulated by the applied charge density. Based on PFSA ionomers, it demonstrates high-performance electrochemically activated lap-shear clutches capable of sustaining a force capacity (F_c) of 200 N cm^-2 with an on/off ratio of 462, maintaining more than 2 months of adhesion retention without a power supply and enduring more than 50 on/off adhesion cycles for repeated use-outperforming existing electrochemical adhesives.