A Dissolvable Smartwatch Makes for Easier Electronics Recycling
August 6, 2021 | ACSEstimated reading time: 2 minutes
Small electronics, including smartwatches and fitness trackers, aren’t easily dismantled and recycled. So when a new model comes out, most users send the old devices into hazardous waste streams. To simplify small electronics recycling, researchers reporting in ACS Applied Materials & Interfaces have developed a two-metal nanocomposite for circuits that disintegrates when submerged in water. They demonstrated the circuits in a prototype transient device — a functional smartwatch that dissolved within 40 hours.
Planned obsolescence and the fast pace of technology innovations leads to new devices that are continuously replacing old versions, which generates millions of tons of electronic waste per year. Recycling can reduce the volume of e-waste and is mandatory in many places. However, it often isn’t worth the effort to recycle small consumer electronics because their parts must be salvaged by hand, and some processing steps, such as open burning and acid leaching, can cause health issues and environmental pollution. Dissolvable devices that break apart on demand could solve both of those problems. Previously Xian Huang and colleagues developed a zinc-based nanocomposite that dissolved in water for use in temporary circuits, but it wasn’t conductive enough for consumer electronics. So, they wanted to improve their dissolvable nanocomposite’s electrical properties while also creating circuits robust enough to withstand everyday use.
The researchers modified the zinc-based nanocomposite by adding silver nanowires, making it highly conductive. Then, they screen-printed the metallic solution onto pieces of poly(vinyl alcohol) — a polymer that degrades in water — and solidified the circuits by applying small droplets of water that facilitate chemical reactions and then evaporate. With this approach, the team made a smartwatch with multiple nanocomposite-printed circuit boards inside a 3D printed poly(vinyl alcohol) case. The smartwatch had sensors that accurately measured a person’s heart rate, blood oxygen levels and step count, and sent the information to a cellphone app via a Bluetooth connection. The outer package held up to sweat, but once the whole device was fully immersed in water, both the polymer case and circuits dissolved completely within 40 hours. All that was left behind were the watch’s components, such as an organic light-emitting diode (OLED) screen and microcontroller, as well as resistors and capacitors that had been integrated into the circuits. The researchers say the two-metal nanocomposite can be used to produce transient devices with performance matching that of commercial models, which could go a long way toward solving the challenges of small electronics waste.
Suggested Items
Kimball's Worldwide Headquarters Employees Donate Time to 'Dogs Day Out' Event
05/31/2024 | Kimball Electronics Inc.Recently, 15 employees from the Kimball Electronics World Headquarters donated work time to help the Dubois County Humane Society exercise their dogs during a "Dogs Day Out" event.
EOS Brings IPC Standards to South Korea
05/31/2024 | Tina Choi, IPC AsiaWe are well aware of the saying, “There are no borders in the world economy.” To grow, a company must think about establishing a global customer base, no matter how small the product. So, the product must be manufactured according to a common global standard. In electronics manufacturing, one South Korean company learned that IPC standards should be applied immediately.
Remembering Michael Gasch: Europe's Foremost PCB Industry Expert
05/30/2024 | EIPCKnown and appreciated far beyond the European electronics industry, Michael Gasch initially worked at DYNAMIT NOBEL AG from 1971 to 1988, including 11 years as sales manager for electrical melting products in Troisdorf and 6 years as managing director and regional representative for Southeast Asia at DYNAMIT NOBEL Singapore. B
Renesas Announces Execution of Facilities Agreement for Altium Acquisition
05/30/2024 | RenesasAs announced in a previous press release, Renesas Electronics Corporation, a premier supplier of advanced semiconductor solutions, reached an agreement with Altium Limited, a global leader in electronics design systems, in which Renesas will acquire all outstanding shares of Altium, making Altium a wholly-owned subsidiary of Renesas, subject to the satisfaction of certain conditions.
Nano Dimension Announces Major Enhancement to its Additive Electronics Robotics Systems from Essemtec
05/30/2024 | Nano DimensionNano Dimension Ltd., a leading supplier of Additively Manufactured Electronics (AME) and multi-dimensional polymer, metal and ceramic Additive Manufacturing (AM) 3D printing solutions, announced a major enhancement to its Additive Electronics (AE) offering from its Essemtec product group that has introduced a new jet-on-the-fly capability, significantly enhancing the speed of additive electronics dispensing by up to 3x, marking a major advancement in AME.