Disposable electronic components could be printed on paper
Image credit: Adapted from ACS Applied Materials & Interfaces 2022, DOI: 10.1021/acsami.2c13503
Researchers in the US have created a prototype circuit board made from a sheet of paper with fully integrated electrical components, meaning it can be burned or left to degrade, leaving no waste behind.
A team at the State University of New York has devised a way of minimising e-waste, by developing disposable electronic components that can be printed on a sheet of paper.
They designed a paper-based amplifier-type circuit that incorporates resistors, capacitors and a transistor, which would be both easy to carry and to recycle.
The team first used wax to print channels onto a sheet of paper in a simple pattern. After melting the wax so that it soaked into the paper, the researchers printed semiconductive and conductive inks, which soaked into the areas not blocked by wax. Then, they screen-printed additional conductive metal components and cast a gel-based electrolyte onto the sheet.
The final circuit was very flexible and thin, just like paper, even after adding the components. To demonstrate the degradability of the circuit, the team showed that the entire unit quickly burned to ash after being set on fire. They say this represents a step toward producing completely disposable electronic devices.
The amount of electronics produced is likely to increase considerably in the coming years, with the use of raw materials in the sector expected to double by 2050. Electronic waste has also almost doubled over the past 16 years and only around 20 per cent is collected efficiently.
Discarded electronic devices, such as mobile phones, are a fast growing source of waste. One study has estimated that the world’s mountain of discarded electronics, for 2021 alone, weighed 57 million tonnes - more than the entire Great Wall of China.
However, most small electronic devices contain circuit boards that are made from glass fibres, resins and metal wiring. These boards are not easy to recycle and are relatively bulky, making them undesirable for use in point-of-care medical devices, environmental monitors or personal wearable devices.
In contrast, this new circuit would be simple to manufacture and had all the electronic components fully integrated into the sheet which could be burned or easily disposed of, meaning it could help address the challenge of e-waste.
The team published its findings in ACS Publications.
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