The research team comprises of researcher Hyunseon Seo and senior researcher Dr. Donghee Son of the Korea Institute of Science and Technology's Biomedical Research Institute and postdoctoral candidate Dr. Jiheong Kang and Professor Zhenan Bao of Stanford University (chemical engineering).
Interest in the development of wearable electronic devices is growing rapidly and the KIST-Stanford research team decided to look at and develop a new material that can be used as an interconnect that could offer the same properties as existing wearable materials as well as high levels of electrical conductivity and stretchability, allowing the more stable transmission of electricity and data from the human body to electronic devices.
The KIST-Stanford team dispersed silver micro-/nano-particles throughout the highly stretchable and self-healable polymer material to achieve a new design for a nanocomposite material with high stretchability and high electrical conductivity.
During tests, the material used as an interconnect and attached to the human body to allow for the measurement of biometric signals in real time. The signals were then transmitted to a robotic arm, which successfully and accurately imitated (in real time) the movements of a human arm.
Contrary to typical materials, the electrical conductivity (and thus performance) of which decreases when the shape of the materials is changed by an applied tensile strain, the new material developed by the KIST research team was able to show a dramatic increase in conductivity under a tensile strain of 3,500 percent. In fact, electrical conductivity rose over 60-fold, achieving the highest conductivity level reported worldwide so far.
Even if the material is damaged or completely cut through, it is able to self-heal, a property that is already gaining attention from academia.
The KIST team investigated a particular phenomena called electrical "self-boosting," which refers to the self-improvement of electrical conductivity through the rearrangement and self-alignment of a material's micro-/nano-particles when the material is stretched. The team also discovered the mechanism of such dynamic behaviour of micro-/nano-particles by using SEM and microcomputed tomography (μ-CT) analyses.
Seo said, "Our material is able to function normally even after being subjected to extreme external forces that cause physical damages, and we believe that it will be actively utilised in the development and commercialisation of next-generation wearable electronic devices," while Son stated, "Because the outcome of this study is essentially the foundational technology necessary for the development of materials that can be used in major areas of the Fourth Industrial Revolution, such as medical engineering, electrical engineering, and robotics, we expect that it will be applicable to diverse fields."
