"Frozen" Ionogels with High and Tunable Toughness for Soft Electronics

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Ionogels are promising for flexible electronics and energy storage.
• Existing ionogels often exhibit poor mechanical properties, limiting their applications.
• Developing mechanically robust ionogels is crucial for advanced device performance.

Purpose of the Study:

• To develop a universal strategy for toughening ionogels.
• To create ionogels with enhanced mechanical properties and functionalities.
• To demonstrate the potential of these ionogels in wearable electronic devices.

Main Methods:

• A novel strategy involving freezing the polymer network via network design was employed.
• Ionogels were prepared by copolymerizing isobornyl acrylate (IBA) and ethoxyethoxyethyl acrylate (CBA) in ionic liquid.
• A bicontinuous phase-separated structure was achieved with rigid, ionic liquid-free PIBA segments and flexible PCBA phases.

Main Results:

• The toughened ionogels exhibited significantly improved mechanical properties: rigidity (48.5 MPa), strength (4.19 MPa), and toughness (8.19 MJ·m⁻³).
• The ionogels demonstrated remarkable thermo-softening performance, strong adhesiveness, high ionic conductivity, shape memory effects, and good biocompatibility.
• The ionogel functioned effectively as an ionic skin, accurately detecting body motions over extended periods.

Conclusions:

• The developed network design strategy offers an effective method for toughening ionogels.
• These mechanically enhanced ionogels possess multiple desirable properties for advanced applications.
• This work paves the way for the development of robust and stable ionotronic devices.