A tiny device that can be reprogrammed using a laser could lead to adaptable devices for computing, imaging and telecommunications. Most devices are built to perform a particular job. If you want them to do something different, you generally need to replace a component, rewire the system or manufacture a new one. For example, every time you ask a large language model like ChatGPT or Claude a question, many electrical signals race through computer chips, carrying information and performing calculations. This takes energy, and lots of it.