KIST develops high-performance memory devices that dissolve in water, addressing the E-waste problem

The use of electronics in various forms is on the rise, from wearable devices like smartwatches to implantable devices like body-implanted sensors, skin-worn smart patches, and disposable monitoring devices. These devices, which are inevitably discarded after use, contribute to the growing problem of electronic waste (e-waste), a significant environmental concern.

The Korea Institute of Science and Technology (KIST) has announced that a joint research team, led by Dr. Sangho Cho of the Center for Extreme Materials Research and Dr. Yongho Joo of the Center for Functional Composite Materials Research, has developed a polymeric material that offer high-performance data storage while completely degrading within days when immersed in water. The material is biocompatible and stable enough for implantation in the human body, and the onset of degradation can be controlled by adjusting the thickness and the composition of the protective layer. Once this protective layer dissolves, the material degrades naturally in water within approximately three days, without leaving any residue.

Although electronic devices that dissolve in water have previously been developed, they have typically suffered from poor data storage capabilities, limited performance, and vulnerability to repeated mechanical deformation. To address these challenges, the KIST research team designed a new molecular structure (PCL-TEMPO), which combines TEMPO-a functional organic molecule capable of storing electrical information-with polycaprolactone (PCL), a biodegradable polymer. This novel design enables both electrical signal storage and natural degradation to be achieved within a single molecular system.

The memory device made from this material showed excellent signal discrimination, successfully distinguishing between ON and OFF states over one million cycles. It also retained stored data reliably for more than 10,000 seconds. Moreover, the device showed no degradation after more than 250 write-erase cycles or after being bent over 3,000 times-an exceptional combination of durability and performance for an organic electronic device.

This technology is not limited to implantable medical devices; it also holds promise for applications in disposable healthcare monitoring systems, surgical implants that naturally degrade post-operation, eco-friendly data storage devices, and one-time-use military reconnaissance tools. In particular, its ability to disappear in the body without requiring surgery removal could significantly reduce patient discomfort and healthcare costs. Furthermore, this technology addresses the growing issue of e-waste and supports global efforts toward carbon neutrality.

"This achievement is technologically significant as it marks the first example of integrating physical self-destruction into a high-performance organic memory device," said Dr. Sangho Cho. "In the future, we aim to evolve this into an 'intelligent transient electronic device' by incorporating self-healing and photo-responsive capabilities, accelerating the commercialization of next-generation bioelectronics and eco-friendly devices."

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KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://www.kist.re.kr/eng/index.do

This research was supported by the Ministry of Science and ICT (Minister Yoo Sang-im) under the KIST Institutional Program and the Korea Research Foundation Mid-Career Researcher Support Project (RS-2023-00208313). The findings were published in the latest issue of the international journal Angewandte Chemie International Edition (IF 16.1, JCR field 5.8%).