Moisture-responsive ultralow-hysteresis polymer ionogels for adhesion-switchable strain sensing

Area of Science:

• Materials Science
• Polymer Chemistry
• Soft Electronics

Background:

• Soft electronics require materials with tunable adhesion to prevent damage and ensure signal integrity.
• Developing ionogels with switchable adhesion and stable mechanical properties remains a significant challenge.

Purpose of the Study:

• To design and fabricate novel polymer ionogels with adhesion-switchable properties and ultralow mechanical hysteresis.
• To investigate the potential of these ionogels in advanced soft electronic applications.

Main Methods:

• Utilizing binary ionic solvents with oppositely charged ionic components to engineer ionogel properties.
• Inducing moisture-triggered phase separation to control adhesion characteristics.
• Characterizing viscoelastic behavior and mechanical hysteresis under large strain.

Main Results:

• The developed ionogels demonstrate moisture-induced phase separation, leading to switchable adhesion with >99% detaching efficiency.
• Ultralow mechanical hysteresis (approx. 3%) was observed, maintaining viscoelasticity in the rubbery plateau region.
• Ionogel films were successfully integrated into a smart clamp for selective prey activation based on vibration sensitivity.

Conclusions:

• This novel approach enables the creation of ionogels with tunable adhesion and stable mechanical performance for soft electronics.
• The demonstrated flytrap-like selective activation highlights the potential of these materials in advanced sensing and actuation systems.
• This research opens new avenues for designing sophisticated soft electronic devices with enhanced functionality.