Nanotube-Based Actuator and Sensor Paradigm: Conceptual Design and Challenges

With the widespread application of mechatronic concepts to dynamic systems in recent years, interest has been focused on the substitution of piezoelectric ceramic (PZT) fibers for conventional electrical motors and actuators. Piezoelectricity effects in elongated and poled PVDF as well as the ferroelectric properties have been observed for a number of decades. Although PVDF copolymers have found diverse uses in industrial applications, such as ultrasonic transducers and vibration damping, their low stiffness and electromechanical coupling coefficients have limited their use. To improve the performance and capability of future automated systems, the development of next generation actuator subsystems utilizing nanotubes is presented. Specifically, the actuation mechanism associated with carbon and boron nitride (BN) nanotube-based actuators, and ultimately manufacturing macro-level actuators compromised of functional nanotubes are discussed in this paper. This exciting area of research is motivated by discovery of bond extension in charged nanotubes. Termed “artificial muscles”, such actuators provide wonderful opportunities in MEMS due to their incredible strength and stiffness, with relatively low (∼10 V) driving voltage. The proposed nanotube-based actuator configuration could be utilized for many applications such as miniature motors, vibration control of flexible structures, micro scale robotic systems, biomedical (drug delivery and tumor removal), and power generation applications.