A superworm consumes an OECT device during the biodegradation experiment. [Provided by GIST]
A superworm consumes an OECT device during the biodegradation experiment. [Provided by GIST]

Researchers have developed a technology that could offer a sweeping solution to the growing problem of electronic waste, which is difficult to dispose of and poses mounting environmental hazards.

The Gwangju Institute of Science and Technology (GIST) announced Monday that a joint research team led by professor Yoon Myung-han of its Department of Materials Science and Engineering and professor Shim Bong-seop of Inha University's Department of Chemical Engineering has developed an eco-friendly electronic device that worms can ingest and biodegrade.

Demand for low-cost sensors that collect data in real time across diverse locations has been rising with advances in environmental monitoring and biosensor technology.

Sensors, however, are often difficult to retrieve after use and frequently end up as e-waste. Previous research on eco-friendly electronic devices had largely been limited to confirming the biodegradability of individual materials, falling short of practical application in actual devices.

The research team focused on the organic electrochemical transistor (OECT), a device widely used in biosensors and environmental sensors.

The team combined montmorillonite (MMT), a clay mineral that worms can ingest, with PEDOT:PSS, a conductive polymer material commonly used in OECTs, to develop a composite material with both degradability and strong electrical performance.

The team also applied a paper substrate-based printing process and developed waterproofing and reinforcement techniques to offset paper's vulnerability to moisture.

Using the composite material, the researchers fabricated an actual OECT and confirmed that it operates stably even at low voltages.

To verify whether worms could break down the device in practice, the team conducted an experiment using superworms.

From left: GIST professor Yoon Myung-han, Inha University professor Shim Bong-seop, GIST doctoral candidate Na Hyeon-jun, Inha University doctoral candidate Hong Young-beom, GIST postdoctoral researcher Cho Il-young, and GIST doctoral candidate Lee Da-young. [Provided by GIST]
From left: GIST professor Yoon Myung-han, Inha University professor Shim Bong-seop, GIST doctoral candidate Na Hyeon-jun, Inha University doctoral candidate Hong Young-beom, GIST postdoctoral researcher Cho Il-young, and GIST doctoral candidate Lee Da-young. [Provided by GIST]

The superworms' survival rate remained at around 95 percent throughout the experiment, and the worms fully consumed a 3-centimeter-by-3-centimeter device — including the active layer, substrate and electrodes — in about one week.

Analysis of the worms' frass also confirmed that the devices had undergone actual chemical decomposition, not merely physical fragmentation.

"This research is significant in that it demonstrates an entire device made from eco-friendly materials can be broken down by worms," Yoon said. "We expect it to chart a new course for the development of sustainable electronic devices and eco-friendly electronics."

The findings, supported by the National Research Foundation of Korea, were published June 29 in ACS Applied Polymer Materials, a journal of the American Chemical Society.


nbgkoo@heraldcorp.com