Preparation and Performance of Piezoelectric Hydrogels for Accelerating Wound Healing in Damaged Plants
In ecological restoration projects such as wetland reconstruction and mine reclamation, seedling transplantation or mechanical damage often leads to slow healing, reducing survival rates and weakening carbon sequestration and soil-water conservation functions. To address secondary pollution from traditional chemical remediation, this study developed a self-powered piezoelectric hydrogel for green electrical stimulation of plant wounds. The hydrogel, based on polyacrylamide/polyethylene glycol (PAM/PEG) with CaCl2, formed a microporous, locally ordered piezoionic network. Characterization included microstructure, piezoionic response, and water retention. At 30 °C and 55% relative humidity, the hydrogel retained about 70% mass after 80 h of continuous water loss. Under simulated environmental mechanical forces, the hydrogel generated a peak voltage of approximately 6 mV. In tomato seedling stem models, wound callus area ratios reached approximately 49.50%, 64.87%, and 86.13% at 3, 5, and 10 days, respectively, when the hydrogel was attached and driven by environmental forces. The PAM/PEG/CaCl2 hydrogel efficiently converts environmental mechanical energy into mild electrical signals, promoting plant wound healing, reducing exogenous chemical use, and offering a low-carbon, environmentally friendly material pathway for ecological restoration and urban green space management.