Development of Transparent and Flexible Neural Electrodes Using Thin Gold

Professor Kang Hong-gi's Team at DGIST

Professor Hongki Kang (back), majoring in Information and Communication Convergence at Daegu Gyeongbuk Institute of Science and Technology (DGIST), and master’s graduate Woongki Hong (front), who developed a transparent and flexible brain electrode device made of very thin gold.

[Asia Economy Reporter Kim Bong-su] The research team led by Professor Kang Hong-gi from the Department of Information and Communication Convergence at Daegu Gyeongbuk Institute of Science and Technology (DGIST) has developed a new thin-film neural electrode device for efficient measurement of brain neural signals. Made of ultra-thin gold, this device is transparent and flexible, making it promising for use in the recently focused brain-machine interface technology.

Recently, scientists studying the brain have been developing optoelectronic hybrid technologies that enable brain signal measurement and stimulation using light, such as optogenetics, beyond the conventional electrical brain signal measurement and stimulation techniques. The core of this technology is reading the brain's electrical signals and developing brain neural circuit modulation and brain disease treatment interface technologies using light. Transparent and flexible neural electrode materials are essential for these technologies, but the complex manufacturing processes have posed significant material limitations.

Professor Kang's team succeeded in developing a transparent and highly flexible neural electrode structure by utilizing electrodes made of ultra-thin gold with a thickness of less than 10 nm (nanometers). The electrodes, developed to be compatible with existing manufacturing methods for mass production, exhibit a high transmittance of up to 77% and excellent conductivity below 5 Ω/sq (ohms per square), as well as flexibility that allows bending with a curvature of 1 mm.

The electrodes developed by Professor Kang's team were also confirmed to be superior in several aspects compared to existing electrodes in terms of electrochemical properties and transparency, which are important for cell imaging-related research and development. It is expected that through brain-machine interface technology, research on electrical signals of brain nerves will be widely applied in brain-related fields such as neural prosthetic operation and brain disease treatment.

Professor Kang stated, “The transparent and flexible ultra-thin metal neural electrode development technology developed through this research is a new core technology for optoelectronic hybrid brain-machine interfaces,” and added, “It is expected to be utilized for the application of new forms of brain-machine interface technology, transparent biosensors, wearable devices, and the practical use of new-concept bioelectronic devices.”

□ This research was conducted under the DGIST general project, led by Hong Woong-gi, a master's student in the Department of Information and Communication Convergence, in international collaboration with the team of Professor Anna Rostedt Punga, a clinical neurophysiology expert from the prestigious Swedish university Uppsala University. The research results were published online on Tuesday, November 21, in the international academic journal ‘Advanced Functional Materials’ in the related field.