Aminated Lignin/Cellulose-Based Hydrogel with High Adhesion for Wearable Sensors

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomaterials

Background:

• Hydrogels are crucial for wearable sensors, enabling flexibility, stretchability, and conductivity.
• Achieving multifunctional hydrogel sensors with superior mechanical strength, self-adhesion, and stimulus responsiveness remains a challenge for practical applications.

Purpose of the Study:

• To develop a one-pot method for preparing a multifunctional conductive hydrogel.
• To enhance hydrogel properties by incorporating aminated lignosulfonate (A-LS) and aminated cellulose nanocrystals (A-CNC).
• To explore the potential of renewable forest biomass resources in creating advanced sensor materials.

Main Methods:

• A one-pot synthesis approach was employed to create the conductive hydrogel matrix.
• Aminated lignosulfonate (A-LS) and aminated cellulose nanocrystals (A-CNC) were introduced into the hydrogel.
• The synergistic effects of a dynamic reversible noncovalent bond network and nanoparticles were utilized.

Main Results:

• The resulting hydrogel demonstrated excellent mechanical properties due to the synergistic effects.
• Remarkable and sustainable adhesion strength was achieved (24 kPa on pig skin, >18 kPa after 20 cycles).
• The hydrogel sensor exhibited a wide operating range (0-200%), high sensitivity (GF=0.71 at 0-100% strain, GF=3.15 at 100-200% strain), and a fast response time (320 ms).

Conclusions:

• The developed conductive hydrogel possesses multifunctionality, including excellent mechanical strength, adhesion, and stimulus responsiveness.
• The use of A-LS and A-CNC from renewable forest biomass offers a sustainable approach for green chemistry.
• This work paves the way for advanced wearable sensors with improved performance and eco-friendly material sourcing.