The abrupt first-order metal-insulator phase transition in single-crystal vanadium dioxide nanowires (NWs) is engineered to be a gradual transition by axially grading the doping level of tungsten. We also demonstrate the potential of these NWs for thermal sensing and actuation applications. At room temperature, the graded-doped NWs show metal phase on the tips and insulator phase near the cente...

This research focuses on modeling and control of a light-weight and inexpensive pneumatic robot that can be used for position tracking and for end-e ector force control. Unlike many previous controllers, our approach more fully accounts for the nonlinear dynamic properties of pneumatic systems such as servovalve ow characteristics and the thermodynamic properties of air compressed in a cylinder...

There are two different ways of using SMA wires as actuators for shape control of flexible structures; which can be either embedded within the composite laminate or externally attached to the structure. Since the actuator can be placed at different offset distances from the beam, external actuators produce more bending moment and, consequently, considerable shape changes with the same magnitude...

This research focuses on modeling and control of a light-weight and inexpensive pneumatic robot that can be used for position tracking and for end-effector force control. Unlike many previous controllers, our approach more fully accounts for the nonlinear dynamic properties of pneumatic systems such as servovalve flow characteristics and the thermodynamic properties of air compressed in a cylin...

This paper summarizes the design and development of a fault tolerant linear electromechanical actuator for the lower stage thrust vector control of a satellite launch vehicle. Power electronics and electric machine technologies have evolved to the point that high-power electromechanical actuators present a viable alternative in applications historically served by hydraulic devices. In selecting...

Traditional MEMS actuators have limited stroke and force characteristics. This paper describes the development of a hybrid actuation solution, which utilizes a micro-machined actuator array to provide switching of mechanical motion of a larger mesoscale piezo-electric actuator. One motivating application of this technology is the development of a tactile display, where discrete mechanical actua...