S. Korean researchers develop electronic device that can be eaten by worms

SEATTLE (Scrap Monster): South Korean researchers have developed an electronic device that can be broken down after use by being eaten by worms, in a finding that could open a new route for tackling electronic waste.

The achievement is significant because the team did not simply produce an environmentally friendly material. Instead, it demonstrated through experiments that an entire working electronic component could be processed biologically after use.

The Gwangju Institute of Science and Technology, or GIST, said on 6 July that a joint research team led by Professor Myung-Han Yoon of its Department of Materials Science and Engineering and Professor Bong Sup Shim of Inha University's Department of Chemical Engineering had developed an eco-friendly electronic device that can be consumed and decomposed by worms.

The study focused on an organic electrochemical transistor, or OECT, a type of device used in sensors and bioelectronic systems. The findings were published online on 29 June in ACS Polymer Science & Technology, a journal published by the American Chemical Society.

The central point of the research is not merely the creation of a material that can degrade, but the development of an electronic device designed to degrade as a whole.

Previous studies on environmentally friendly electronics have often focused on whether individual materials can break down in natural conditions. But real electronic devices are complex structures, made up of active layers, electrodes, substrates and protective elements. The fact that one material can degrade does not necessarily mean that the entire device can be disposed of without leaving an environmental burden.

The joint research team sought to address that gap by testing whether a fully functioning OECT could be consumed and broken down by worms.

OECTs use interactions between ions in an electrolyte and conducting polymers to amplify electrical signals. They are seen as promising components for biosensors, environmental sensors and wearable electronic devices. OECT-based biosensors have attracted growing attention in biomolecular detection because of their low operating voltage, biocompatibility and signal-amplifying properties.

The challenge is what happens after such devices are used.

Low-cost sensors installed across wide areas, such as those used for environmental monitoring or smart farming, are often difficult to retrieve one by one. The same problem applies to disposable electronic components used for medical diagnostics or short-term monitoring.

As digitalization and the expansion of the Internet of Things increase demand for electronic devices, e-waste has already become a major environmental concern. According to the UN's Global E-waste Monitor 2024, the world generated 62 million tonnes of e-waste in 2022, an 82% increase from 2010. The figure is projected to rise to 82 million tonnes by 2030, while only 22.3% was formally collected and recycled in 2022.

To address this issue, the researchers turned to montmorillonite, or MMT, a clay mineral that can be consumed by worms. Clay alone, however, has low electrical conductivity, making it difficult to apply directly to electronic devices without compromising performance.

The team combined the clay with PEDOT, a conducting polymer widely used in OECTs, to create a composite material that could provide both degradability and electrical performance. They also used a paper-substrate-based printing process and introduced waterproofing and reinforcement techniques to compensate for paper's weakness in moisture-rich conditions.

The OECT made with the composite material was found to operate stably even at low voltage.

The researchers then conducted feeding experiments using superworms to test whether the device could actually be broken down. According to the team, the worms consumed the entire 3cm-by-3cm device, including its active layer, substrate and electrodes, in about a week.

The survival rate of the superworms remained at around 95% during the experiment. Analysis of their frass, or excrement, also showed that the process involved chemical changes, suggesting that the device had not merely been physically fragmented but had undergone actual decomposition.

The study is being viewed as more than a laboratory demonstration. It adds a new approach to existing e-waste strategies, which have largely focused on collection and recycling: designing electronic devices from the outset so that they can disappear after use.

The technology could be applied to areas where sensors are deployed in large numbers and are difficult to recover, including environmental monitoring, healthcare sensing and smart agriculture. The use of printing-based manufacturing also points to the possibility of low-cost, large-scale production.

Professor Yoon said the study was meaningful because it proved that an entire device made with eco-friendly materials could be degraded by worms. He said the findings could help set a new direction for sustainable electronic devices and environmentally friendly electronics research.

Professor Shim said the key distinction of the work was that, while earlier research had focused on developing individual degradable materials, this study demonstrated that a real working device could be completely consumed by worms.

Experts say the broader direction of e-waste policy and technology is shifting from simple recycling towards environmental design at the manufacturing stage. Making products that last longer, are easier to repair and can be collected more efficiently remains important. But for ultra-small or disposable electronic devices that are structurally difficult to retrieve, end-of-life treatment may also need to be built into the product design itself.

The research is not at a stage where it can be applied immediately to all electronic devices. But at a time when sensors are becoming smaller, cheaper and more widely distributed, it raises a significant question for the electronics industry: how should the end of an electronic device be designed?

Courtesy: www.koreapost.com