Researchers have created a new glass-ceramic that emits light in response to mechanical stress, a property known as mechanoluminescence. With further development, the new material could be used to create a light source that is switched on by mechanical stress. This could be useful for monitoring stress in artificial joints in the body or providing warnings of dangerous stress or fractures in buildings, bridges and other structures. https://phys.org/news/2022-07-glass-ceramic-emits-mechanical-stress.html