Fabrication and Characterization of Multi-Stimuli-Responsive Hydrogels with Robust Mechanical Properties, Good Self-Healing, and Substrate Adhesiveness Using a Traditional Chemical Crosslinker and Initiator-Free Approach

Hydrogels are essential in various applications, including biomedical fields, robotics, sensors, and wearable technologies. Traditional fabrication methods often involve chemical crosslinkers and initiators, which can introduce toxicity and limit practical use. This study presents an innovative approach to creating multifunctional, multi-stimuli-responsive hydrogels without using these traditional components. By polymerizing AMPS, DMAA, and MAA monomers using environmentally friendly AlCl₃·6H₂O as a crosslinker via UV polymerization, the study produces hydrogels exhibiting good mechanical properties such as tensile strength (3.02 ± 0.12 MPa), toughness (20.01 ± 1.8 J m⁻³), superior stretchability (2182.4 ± 114% elongation), and good compression resistance in addition to possessing self-healing capabilities, ionic conductivity, and responsiveness to temperature, pH, and ionic strength. This innovative technique represents a significant advancement toward developing sustainable hydrogels suitable for diverse biomedical, robotic, and sensor, technology applications.