Chemically Modified Graphene for Sensing and Nanomechanical Applications

摘要

Chemically modified graphene (CMG) has emerged as a new material whose many attractive properties complement those of pure graphene. Graphene, a single atomic sheet of carbon bonded in a honeycomb lattice, has remarkable physical properties ranging from near-ballistic electron conduction to extremely high mechanical stiffness (more than five times that of steel). Such extreme properties motivate researchers to investigate these materials for use in applications ranging from high-frequency, low-power electronics, to flexible displays, chemical/biological sensors, and high-frequency electromechanical devices. We have developed a process to form large-area, ultra-thin CMG films that enable us to investigate CMG properties and to explore prototype devices. Using these films we have fabricated state-of-the-art chemical sensors and nanomechanical resonators. For chemical sensors, we have increased the sensitivity and reduced the level of noise by tuning the CMG film chemistry. These optimized sensors are capable of real-time detection of explosives and the three main classes of chemical-warfare agents at parts-per-billion concentrations. For nanomechanics, we have utilized chemical modification to produce suspended films under high tension. These high-stiffness, low-mass resonators display quality factors (up to 4000) and figures of merit well exceeding those of pure graphene resonators and are comparable to diamond thin films. Together, these results demonstrate that CMG is an inexpensive, high- performance material that will find application in a wide range of defense and commercial applications.