Scientists are positioning a dissolvable smartwatch as a next step solution to tackling e-waste.
So far, disassembly has been the favoured method for the extraction of precious metals contained in metal frames. This approach works well for large household appliances such as washing machines but not so much for smaller offerings. This is on account of the fact that manual salvaging of parts from gadgets such as smartwatches and fitness bands could involve dangerous processes such as open burning or acid leaching.
Dissolvable devices that break apart on demand could provide an alternative solution to the problem.
To produce the innovative smartwatch, the research team modified an existing zinc-based nanocomposite material by adding silver nanowires to it. Then, they printed the metallic solution to a water degradable plastic case, solidifying the circuits by applying small drops of water that facilitate chemical reactions and then evaporate.
The smartwatch’s performance holds up to conventional models, being capable of measuring a person’s heart rate, blood oxygen level and step count and sending that information to a mobile phone app via Bluetooth. It can also withstand sweat and water droplets as well as a certain degree of humidity, only dissolving when fully submerged in water. The prototype disintegrates in a 40-hour span, leaving behind only components such as its OLED screen and microcontroller.
In 2019, the world generated 53,6 million metric tons of e-waste of which only 17,4% was recycled. With planned obsolescence and overt consumerism taking its toll, the e-waste generation is set to rise in the foreseeable future. Dissolvable electronics may not solve the e-waste crisis but go a long way towards addressing the challenge of small electronic waste.