Many materials collapse when shaken or squished, but scientists have engineered a gel that reacts to vibrations by gaining strength rather than weakening.
Aaron Esser-Kahn at the University of Chicago in Illinois and his colleagues wanted to harness the energy from mechanical forces to create chemical bonds in a material’s structure. They crafted a soft matrix using the structural carbohydrate cellulose and filled it with zinc oxide and two types of polymer.
When this composite structure is shaken vigorously for many hours, the zinc oxide converts the energy from the vibrations into a flow of electrons. This flow powers a reaction that forms bonds between the two types of polymer, generating a complex polymer network within the cellulose scaffold. As a result, the composite is up to 66 times stronger and is less easily deformed than the same material that has not been subjected to vibration.
This material could have a wide range of applications, including in self-strengthening adhesives and medical devices, the authors say.