Easier to recycle electronics with metal that dissolves in water Researchers have succeeded in developing a metal composite that dissolves in water. The scientists expect the composite to help recycle small electronic devices. After submerging a smartwatch in a bath of water for 40 hours, the watch components soaked off, ready for a second use. To make the recycling process of consumer electronics easier, researchers devised a nano-composite of two metals for the electrical circuit (the set of cables, batteries, appliances and switches, through which electricity can flow from one side to the other). The metal mixture disintegrates when placed under water. The scientists presented their findings in the professional journal ACS Applied Materials & Interfaces. After a bath of several hours, only individual parts of a fully functioning smartwatch remained, such as the OLED screen, resistors, capacitors and switches. The shortage of rare metals is an imminent problem for the energy transition. That is why organizations are calling for global action. Zinc and silver The same researchers have previously succeeded in making a water-soluble composite based on zinc. This mixture alone was not conductive enough to be useful in consumer electronics. Therefore, for this new study, the scientists added silver nanowires that are naturally conductive. They also mounted their own smartwatch (with heart rate monitor, pedometer and Bluetooth connection) with a plastic housing. The latter is not unimportant, since the housing ensures that sweat does not penetrate the moisture-sensitive circuit. Difficult to recycle Consumer electronics often contain precious and scarce metals that you would prefer to reuse. Small electronic devices, such as smartwatches and fitness trackers, are only a recycling headache. The devices consist of different materials that are difficult to dismantle. This makes waste separation and reuse difficult. Moreover, new models follow each other in rapid succession, which does not benefit the waste mountain. In addition, current recycling methods are often energy-intensive or use chemicals that are harmful to the environment. Long way to market The researchers now present a cheap recycling method that uses no extra energy or chemicals. But the question is when we will see the application on a large scale. It will probably be some time before electronic device manufacturers add the nano-composite to their product design. Only if this happens can the innovation contribute to the recycling of electronic waste.