A prototype smartwatch made with zinc-silver nanocomposite circuits inside a poly(vinyl alcohol) case (top) dissolves in water within 40 hours (bottom).
Credit: Adapted from ACS Applied Materials & Interfaces 2021, DOI: 10.1021/acsami.1c07102
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.
Original Article: A dissolvable smartwatch makes for easier electronics recycling
More from: Tianjin University | American Chemical Society
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
Small electronics recycling
- Researchers introduce new step in process for saving e-waste scraps
Researchers at Oak Ridge National Laboratory and Momentum Technologies have piloted an industrial-scale process for recycling valuable materials in the millions of tons of e-waste generated annually ...
- ‘A mountain that just keeps growing.’ What to know about the e-waste left behind by your gadgets
Decades of the tech sector’s pressure to “innovate or die” have led to a long list of useful and flashy household tech products, but many of these same devices end up as e-waste.
- Precious Metals E-Waste Recovery Global Market Report 2022 - ResearchAndMarkets.com
The global precious metals e-waste recovery market is expected to grow from $9.22 billion in 2021 to $9.61 billion in 2022 at a compound annual growth rate (CAGR) of 4.28%. The market is expected to ...
- Raven Recycling embraces uniqueness, carves space for creativity
In many Canadian cities, residents put their recycling out at the curb. It gets taken away, out of sight and mind. In Whitehorse, driving to the local depot and physically dropping off sorted ...
- Novel polymer offers fully recyclable future
Their achievement will help introduce a much broader range of fully recyclable plastic products and should bring into reach an efficient circular economy for durable goods like automobiles. Humanity ...
Go deeper with Google Headlines on:
Small electronics recycling
Go deeper with Bing News on:
Electronics recycling
- Free electronics recycling available starting Tuesday
Take your unwanted electronics to 2134 Texaco Ave., off of Van Horn Road. Green Star of Interior Alaska is taking these items at no charge until Sept. 30.
- Licking County recycling resource: How do I get rid of paint?
In a new quarterly column, Licking County's recycling director aims to answer common questions of how to dispose of different materials.
- Land use, refuse and recycling ‘We’ve seen this movie before’
Recycling became a theme at the July 26 Northbrook Village Board of Trustees meeting. Should the village agree to a rate hike for garbage pickup in return for concierge at-your-door recycling ...
- GUESS and Homeboy Industries Announce the Upcycled Collection ‐ A New Way to Re‐Wear
GUESS will work directly with Homeboy Recycling, a social enterprise branch of Homeboy Industries on the new Upcycled Collection. In partnering with GUESS, Homeboy Recycling has expanded from ...
- E-scrap Recycling Market Worth $7.3 Billion by 2031 | CAGR: 7.6%: States TMR Report
Analysts of a research report by Transparency Market Research (TMR) note that the global e-scrap recycling market is estimated to ...