In the ever-evolving landscape of wearable technology, a groundbreaking achievement has emerged from the labs of Pohang University of Science and Technology (POSTECH). Led by Professor Sei Kwang Hahn and Dr. Tae Yeon Kim from the Department of Materials Science and Engineering, a research team has introduced a cutting-edge integrated wearable sensor device that not only captures but processes two bio-signals simultaneously. This groundbreaking development has the potential to reshape industries, particularly in healthcare and integrated electronic systems.

Figure 1. Bio-Signal Detection. (Credit: POSTECH)

The Power of Gold Beyond Olympic Glory

Figure 1 is the proposed method. Gold, a symbol of wealth and honor in both Eastern and Western cultures, has transcended its iconic role in Olympic medals. Its stability in air, exceptional electrical conductivity, and biocompatibility make it a sought-after element in various fields. In the medical and energy sectors, gold acts as the 'preferred catalyst,' while its applications in cutting-edge wearable technologies are expanding.

Challenges in Wearable Technology

Wearable devices have become instrumental in detecting physical, chemical, and electrophysiological signals for disease diagnosis and management. Recent strides in research aim to create wearables capable of measuring multiple bio-signals concurrently. However, a significant hurdle has been the use of disparate materials for each signal measurement, leading to interface damage, complex fabrication, and reduced device stability. Additionally, diverse signal analyses necessitate complex signal processing systems and algorithms.

Gold Nanowires: A Game-Changing Fusion

The POSTECH research team addressed these challenges by incorporating various shapes of gold (Au) nanowires, merging them with the commonly used silver (Ag) nanowires. By initially developing bulk gold nanowires through the coating of silver nanowires, the team suppressed the galvanic phenomenon. Subsequently, they created hollow gold nanowires by selectively etching the silver, with bulk gold nanowires responding to temperature variations and hollow ones showing high sensitivity to minute changes in strain.

Integration for Seamless Functionality

The engineered gold nanowires were seamlessly patterned onto a substrate made of styrene-ethylene-butylene-styrene (SEBS) polymer, eliminating separations. Leveraging two types of gold nanowires, each with distinct properties, the team successfully engineered an integrated sensor capable of measuring both temperature and strain. Additionally, a logic circuit for signal analysis was created, utilizing the negative gauge factor resulting from micrometer-scale corrugations in the pattern.

Intelligent Wearable Device System

The result? An intelligent wearable device system that not only captures but also analyzes signals simultaneously, all achieved using a single material—gold (Au). The sensors exhibited remarkable performance in detecting subtle muscle tremors, identifying heartbeat patterns, recognizing speech through vocal cord tremors, and monitoring changes in body temperature. Notably, these sensors maintained high stability without causing damage to the material interfaces, showcasing flexibility and excellent stretchability that enables seamless conformity to curved skin.

Future Prospects

Professor Sei Kwang Hahn envisions a futuristic bioelectronics platform capable of analyzing a diverse range of bio-signals. This groundbreaking research, sponsored by the Basic Research Program and the Biomedical Technology Development Program of the National Research Foundation of Korea, and POSCO Holdings, opens new possibilities across various industries, promising advancements in healthcare and integrated electronic systems. The era of intelligent, adaptable wearable technology has dawned, and the possibilities are limitless.

Source: Pohang University of Science & Technology (POSTECH)

Cite this article:

Hana M (2023), Unveiling the Future of Wearable Technology: Gold Nanowires Revolutionize Bio-Signal Detection, AnaTechmaz, pp. 243