Biodegradable Sensors Offer Dual Fix for E-Waste and Air Pollution

INCHEON, South Korea – January 30, 2026 – In a significant step toward a circular economy for electronics, researchers at Incheon National University have developed a new class of high-performance gas sensors that are not only highly sensitive but also fully biodegradable. The innovation, led by Professor Yeong-Don Park, offers a potent solution to two pressing global challenges: the ever-growing mountain of toxic electronic waste and the urgent need for accurate air quality monitoring.

Published in the Chemical Engineering Journal, the research details a novel organic field-effect transistor (OFET) that maintains exceptional stability and performance while being designed to harmlessly break down in seawater. This breakthrough could revolutionize disposable and large-scale sensor applications, particularly in environmentally sensitive areas where device loss or disposal poses a significant pollution risk.

Confronting the Rising Tide of E-Waste

The development arrives at a critical time. The world is grappling with an electronic waste crisis of staggering proportions. In 2022, humanity generated 62 million tonnes of e-waste, a figure projected to swell to 82 million tonnes by 2030. This makes it the planet's fastest-growing domestic waste stream, yet current efforts to manage it are falling dangerously short. Less than a quarter of this waste is properly collected and recycled, leaving vast quantities of hazardous materials to poison ecosystems.

When discarded improperly, toxic substances like lead, mercury, and cadmium leach from electronics into soil and groundwater. In marine environments, the problem is compounded as plastics from discarded devices break down into microplastics. These tiny particles are ingested by marine life, causing internal damage and introducing toxins into the food web, which can ultimately impact human health. The new sensors from Incheon National University directly address this threat with a design centered on biodegradability.

The Science of Sustainable Sensing

Traditional organic electronics, while promising for flexible and lightweight sensors, have been hampered by a critical flaw: their vulnerability to degradation from moisture and oxygen. This shortens their lifespan, reduces performance, and contributes directly to the e-waste problem.

The Incheon team overcame this by creating a novel polymer blend. They combined poly(3-hexylthiophene) (P3HT), a standard organic semiconductor, with poly(butylene succinate) (PBS), a well-known biodegradable polymer used in applications like food packaging. The true innovation, however, lies in the team's use of sophisticated "solvent engineering."

"Using PBS, a well-known biodegradable polymer, and effective solvent engineering, we demonstrated that high sustainability and device performance can be achieved simultaneously," states Prof. Park in the university's announcement. By preparing the blend in a specific mixture of chloroform and dichlorobenzene (CF:DCB), the researchers were able to control the microscopic structure of the sensor's active layer. This process created a uniform, vertically separated structure that was key to the device's success.

This precise fabrication allowed the sensors to remain stable and functional even when composed of up to 90% biodegradable PBS. In contrast, sensors made with a simpler chloroform-only solvent failed when PBS content exceeded 50%. This ability to incorporate a high percentage of biodegradable material without sacrificing electronic performance is the core of the breakthrough.

High Performance for Public Health and Safety

Beyond its environmental benefits, the new sensor excels at its primary function: detecting harmful gases. The study revealed that increasing the PBS content actually enhanced the device's sensitivity to several key air pollutants, including nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and carbon dioxide (CO₂).

The sensor showed particularly high sensitivity to NO₂, a toxic gas primarily produced from burning fossil fuels in vehicles and power plants. NO₂ is a major contributor to respiratory illnesses like asthma and bronchitis, making its accurate detection a public health priority. The lightweight, flexible, and high-performance nature of these biodegradable sensors makes them ideal for portable air quality monitors, wearable health devices, and widespread deployment in smart city networks.

The research also found that increasing the biodegradable polymer content enhanced the physical flexibility of the films, opening up possibilities for use in flexible and wearable electronics that conform to different surfaces.

The Path from Lab to Market

The global market for portable gas sensors is already a multi-billion dollar industry, projected to exceed $4 billion by 2028, driven by industrial safety regulations and growing public concern over air quality. While the demand for eco-friendly alternatives is still emerging, it is rapidly gaining traction due to corporate sustainability goals and tightening environmental regulations.

The Incheon University sensor is uniquely positioned to capture a key segment of this market, especially in applications where biodegradability is a mission-critical feature. Its proven ability to degrade in seawater makes it an ideal candidate for marine research, aquaculture monitoring, and tracking coastal pollution, where the risk of losing a device to the ocean is high.

However, the path to commercialization involves navigating significant hurdles, including scaling up the specialized manufacturing process, ensuring the cost is competitive with conventional sensors, and conducting extensive long-term testing to validate durability in real-world conditions. Furthermore, establishing clear regulatory standards for biodegradable electronics will be essential for market acceptance.

Despite these challenges, the work represents a paradigm shift. "Our eco-friendly and resource-efficient sensors open up new possibilities for environmentally sustainable gas sensing technologies suitable for large-scale or disposable applications," concludes Prof. Park. "In the long term, biodegradable organic sensors could significantly reduce electronic waste, especially for sensors deployed in natural or marine environments."