Polysulfonated covalent organic framework as active electrode host for mobile cation guests in electrochemical soft...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Electrochemical soft actuators require efficient ion transfer across electrolyte-electrode interfaces for optimal performance.
• Actuation is typically governed by the cation-anion affinity for electrode surfaces under an applied electric field.

Purpose of the Study:

• To develop a novel material for enhanced electrochemical actuation.
• To investigate the use of a conjugated polysulfonated covalent organic framework (pS-COF) as a common electrolyte-electrode host.

Main Methods:

• Integration of 1-ethyl-3-methylimidazolium cations within a pS-COF/Nafion membrane composite.
• Characterization of the pS-COF-based actuator's performance, including bending deflection, blocking force, and response time.

Main Results:

• The pS-COF-based actuator demonstrated significant bending deflection at a near-zero voltage of ~0.01 V.
• Achieved an unprecedented blocking force 34 times its own weight.
• Exhibited ultrafast step response with a 1.59-second rising time and no back-relaxation.
• Showcased substantial ultralow-voltage actuation at frequencies up to 5.0 Hz.

Conclusions:

• The pS-COF serves as an effective common electrolyte-electrode host, significantly improving electrochemical actuator performance.
• The developed actuator shows promise for engineering applications, including soft fluidic switches.
• Ultralow-voltage operation and high performance highlight the potential of this new material system.