Soft Conducting Materials for Peripheral Nerve Interfaces

초록

Advances in robotic, electronic, and computer technologies have changed not just our daily life but also biomedical prostheses. Human intention can be delivered to operate artificial prosthetic devices as commanding signals through so called ‘brain-machine interfaces (BMIs)’ or ‘peripheral nerve interfaces (PNIs)’. Although BMIs hold strong future impacts, PNIs are near clinical practice in broad applications such as cochlear implants, implantable defibrillators, cardiac pacemakers, phrenic pacemakers, and artificial limbs. The PNI designs vary from less invasive cuff electrodes, to higher selective intraneural electrodes, and to regenerative electrodes. Challenges of current PNIs, however, are forming chronically functional biotic-abiotic interfaces because their electrode components are mainly composed of hard materials such as metals and ceramics. These materials evoke inflammation responses around electrodes within few weeks, i.e., insulating scar tissues, fibrosis, and neural tissue damages. Thus, the quality and reproducibility of signal communication at the interfaces decay. To prevent these functional failures, wide ranges of soft conducting materials such as conducting polymers, conducting hydrogels, carbon nanotubes, graphenes, and natural polymers are tried. I will discuss the pros and cons of these new materials and briefly introduce our recent efforts to develop chronically implantable PNIs.