Functionalizing Double-Network Hydrogels for Applications in Remote Actuation and in Low-Temperature Strain Sensing

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Multifunctional hydrogels are crucial for applications like artificial muscles, wearable devices, and tissue engineering.
• Key desirable properties include mechanical strength, low-temperature resistance, and stimuli-responsiveness.

Purpose of the Study:

• To fabricate a polyacrylamide/sodium alginate/carbon nanotube (PAAm/SA/CNT) double-network (DN) hydrogel.
• To enhance the hydrogel's low-temperature performance and broaden its applications.

Main Methods:

• Fabrication of PAAm/SA/CNT double-network hydrogels.
• Introduction of calcium chloride (CaCl2) as an additive to improve low-temperature properties.
• Characterization of mechanical strength, conductivity, self-healing, photomechanical deformation, and strain-sensing capabilities.

Main Results:

• The PAAm/SA/CNT hydrogel demonstrated high tensile strength (271.68 ± 6.04 kPa), conductivity (1.38 ± 0.17 S·m⁻¹), and self-healing ability.
• The composite hydrogel showed controllable photomechanical deformations under near-infrared irradiation.
• The addition of CaCl2 maintained excellent mechanical properties and conductivity at -20 °C, alongside good recoverability and strain-sensing capability.

Conclusions:

• The developed PAAm/SA/CNT/CaCl2 hybrid DN hydrogels offer multifunctional properties suitable for extended applications.
• The study provides new methods and inspiration for creating advanced hydrogels for extreme environments.